diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index a2f46b342..4705a5d45 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -23,26 +23,8 @@ jobs:
             bublik/data/migrations/**
             bublik/analytics/migrations/**
 
-  format-check:
-    name: Check Code Formatting
-    needs: detect-changes
-    runs-on: ubuntu-latest
-    if: ${{ needs.detect-changes.outputs.python_files != '' }}
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
-        with:
-          python-version: '3.12'
-
-      - name: Install Black
-        run: pip install $(grep '^black==' requirements.txt)
-
-      - name: Run Black in check mode
-        run: |
-          echo "${{ needs.detect-changes.outputs.python_files }}" | xargs black --check --diff
-
-  lint-check:
-    name: Check Code Quality
+  ruff-check:
+    name: Check Python Quality
     needs: detect-changes
     runs-on: ubuntu-latest
     if: ${{ needs.detect-changes.outputs.python_files != '' }}
@@ -53,26 +35,12 @@ jobs:
           python-version: '3.12'
 
       - name: Install Ruff
-        run: pip install ruff
+        run: pip install $(grep '^ruff' requirements.txt)
 
-      - name: Run Ruff
+      - name: Run Ruff formatter in check mode
         run: |
-          echo "${{ needs.detect-changes.outputs.python_files }}" | xargs ruff check
-
-  f-string-check:
-    name: Check F-String Usage
-    needs: detect-changes
-    runs-on: ubuntu-latest
-    if: ${{ needs.detect-changes.outputs.python_files != '' }}
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
-        with:
-          python-version: '3.12'
-
-      - name: Install Flynt
-        run: pip install flynt
+          echo "${{ needs.detect-changes.outputs.python_files }}" | xargs ruff format --check --diff
 
-      - name: Run Flynt in check mode
+      - name: Run Ruff linter
         run: |
-          echo "${{ needs.detect-changes.outputs.python_files }}" | xargs flynt -f
+          echo "${{ needs.detect-changes.outputs.python_files }}" | xargs ruff check
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 07f6e8ebe..7a2ec2eda 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,8 +1,8 @@
 repos:
 - repo: local
   hooks:
-  - id: run-my-script
-    name: Run My Script
+  - id: ruff-python-quality
+    name: Ruff Python Quality
     entry: ./scripts/pyformat
     language: script
     types: [python]
diff --git a/README.md b/README.md
index e71b894b4..c3b9e5ce6 100644
--- a/README.md
+++ b/README.md
@@ -42,23 +42,44 @@ For now some documentation can be found in **doc/wiki** here.
 
 # Development
 
-## Pre-commit checkings
+## Pre-commit checks
 
-After initial deploy please run the:
+Pre-commit installs a local Git hook that runs before `git commit` creates a
+commit. In this project, the hook runs Ruff on changed Python files via:
+```
+./scripts/pyformat -c <changed-python-files>
+```
+
+Install the hook once after setting up the repository:
 ```
 pre-commit install
 ```
-This will allow the pre-commit tool to run `./scripts/pyformat -c` before each
-commit.
 
-Please note that you can always disable the pre-commit validation by running:
+After that, every `git commit` will automatically run:
+```
+ruff format --check --diff <changed-python-files>
+ruff check <changed-python-files>
+```
+
+If the hook fails, fix the reported issues and run `git commit` again. To apply
+Ruff formatting and autofixes manually, run:
+```
+./scripts/pyformat <path_to_the_changed_file>
+```
+
+You can run the hook manually for all files with:
+```
+pre-commit run --all-files
+```
+
+You can disable the local hook with:
 ```
 pre-commit uninstall
 ```
 
 ## Checking your changes
 
-You can use pyformat script to check your changes.
+You can use pyformat script to run Ruff formatting and lint checks.
 
 For this you need to run:
 ```
diff --git a/bublik/core/auth.py b/bublik/core/auth.py
index 12d721dcb..9a4469cc4 100644
--- a/bublik/core/auth.py
+++ b/bublik/core/auth.py
@@ -70,9 +70,9 @@ def wrapper(*args, **kwargs):
 
 
 def check_action_permission(action):
-    '''
+    """
     Check if the action requires permission.
-    '''
+    """
 
     def wrapper(func):
         @wraps(func)
diff --git a/bublik/core/cache.py b/bublik/core/cache.py
index 66f6fd805..87ca1f7cc 100644
--- a/bublik/core/cache.py
+++ b/bublik/core/cache.py
@@ -159,12 +159,12 @@ def tests(self):
 
 
 class _ProjectSectionCache:
-    '''
+    """
     Base class for project section caches.
 
     Each section cache stores data under keys like
     'project:{project_id}:{SECTION}:{data_key}'.
-    '''
+    """
 
     SECTION: ClassVar[str] | None = None
     KEY_DATA_CHOICES: ClassVar[set[str]] | None = None
@@ -220,7 +220,7 @@ class _TagsCache(_ProjectSectionCache):
     }
 
     def load(self):
-        '''
+        """
         Populate tags cache for the project.
 
         Each cache entry stores a mapping of meta tag IDs to their string
@@ -235,7 +235,7 @@ def load(self):
 
         Value format:
             {meta_id: 'tag_name=tag_value'}
-        '''
+        """
 
         tags = models.Meta.objects.filter(type='tag')
 
diff --git a/bublik/core/config/reformatting/dispatcher.py b/bublik/core/config/reformatting/dispatcher.py
index 7929e8de2..61cde24b5 100644
--- a/bublik/core/config/reformatting/dispatcher.py
+++ b/bublik/core/config/reformatting/dispatcher.py
@@ -62,9 +62,9 @@ def update_config(reformatted_config):
 
 
 class ConfigReformatStatuses(str, Enum):
-    '''
+    """
     All available config reformatting statuses.
-    '''
+    """
 
     SUCCESS = 'success'
     SKIPPED = 'skipped'
diff --git a/bublik/core/config/reformatting/steps.py b/bublik/core/config/reformatting/steps.py
index ff7b08096..c5430314c 100644
--- a/bublik/core/config/reformatting/steps.py
+++ b/bublik/core/config/reformatting/steps.py
@@ -12,10 +12,10 @@
 
 class BaseReformatStep:
     def apply(self, config, **kwargs):
-        '''
+        """
         Reformats the provided content if it has not been reformatted yet,
         and outputs the execution status. Returns the content.
-        '''
+        """
         try:
             if not self.applied(config, **kwargs):
                 config = self.reformat(config, **kwargs)
@@ -28,25 +28,25 @@ def apply(self, config, **kwargs):
             raise err
 
     def applied(self, config, **kwargs):
-        '''
+        """
         Checks whether the step has already been applied.
-        '''
+        """
         msg = 'Subclasses must implement `applied`.'
         raise NotImplementedError(msg)
 
     def reformat(self, config, **kwargs):
-        '''
+        """
         Reformats the provided content.
-        '''
+        """
         msg = 'Subclasses must implement `reformat`.'
         raise NotImplementedError(msg)
 
 
 class UpdateAxisXStructure(BaseReformatStep):
-    '''
+    """
     Reformat passed report config content:
     "axis_x": <str> -> "axis_x": {"arg": <str>}
-    '''
+    """
 
     def applied(self, config, **kwargs):
         content = config.content
@@ -68,12 +68,12 @@ def reformat(self, config, **kwargs):
 
 
 class UpdateSeqSettingsStructure(BaseReformatStep):
-    '''
+    """
     Reformat passed report config content:
     Add the 'sequences' foreign key for all sequences settings
     (sequence_group_arg, percentage_base_value, sequence_name_conversion).
     Rename 'sequence_name_conversion' to 'arg_vals_labels'.
-    '''
+    """
 
     def applied(self, config, **kwargs):
         content = config.content
@@ -109,11 +109,11 @@ def reformat(self, config, **kwargs):
 
 
 class UpdateDashboardHeaderStructure(BaseReformatStep):
-    '''
+    """
     Reformat passed global per_conf config content:
     DASHBOARD_HEADER: {<key>: <label>} ->
     DASHBOARD_HEADER: [{"key": <key>, "label": <label>}]
-    '''
+    """
 
     def applied(self, config, **kwargs):
         return not isinstance(config.content.get('DASHBOARD_HEADER'), dict)
@@ -127,11 +127,11 @@ def reformat(self, config, **kwargs):
 
 
 class UpdateCSRFTrustedOrigins(BaseReformatStep):
-    '''
+    """
     Reformat passed global per_conf config content:
     CSRF_TRUSTED_ORIGINS: ["http://origin1", "origin2", "https://origin3"] ->
     CSRF_TRUSTED_ORIGINS: ["http://origin1", "https://origin2", "https://origin3"]
-    '''
+    """
 
     def applied(self, config, **kwargs):
         content = config.content
@@ -174,13 +174,13 @@ def reformat(self, config, **kwargs):
 
 
 class UpdateLogsFormat(BaseReformatStep):
-    '''
+    """
     Reformat passed global references configs content:
     {"LOGS": {"LOGS_BASE": {"uri": ["uri1", "uri2"], "name": "Logs Base"},
     "BUG_KEY": {"uri": ["uri3", "uri4"], "name": "Bugs Base"}},...} ->
     {"LOGS_BASES": [{"uri": ["uri1", "uri2"], "name": "Logs Base"}],
     "ISSUES": {"BUG_KEY": {"uri": ["uri3", "uri4"], "name": "Bugs Base"}}},...}
-    '''
+    """
 
     def applied(self, config, **kwargs):
         return 'LOGS' not in config.content
@@ -204,7 +204,7 @@ def reformat(self, config, **kwargs):
 
 
 class SimplifyMetaStructure(BaseReformatStep):
-    '''
+    """
     Reformat passed global meta configs content:
     [
         {
@@ -228,7 +228,7 @@ class SimplifyMetaStructure(BaseReformatStep):
             "set-patterns": ["LINUX", "linux-.+$"]
         }
     ]
-    '''
+    """
 
     def applied(self, config, **kwargs):
         return not any(
@@ -266,7 +266,7 @@ def reformat(self, config, **kwargs):
 
 
 class ImproveMetaStructure(BaseReformatStep):
-    '''
+    """
     Reformat global meta config content:
      - remove empty values,
      - split pattern strings into individual elements,
@@ -313,7 +313,7 @@ class ImproveMetaStructure(BaseReformatStep):
             "set-patterns": ["drv", "net_.*$"]
         }
     }
-    '''
+    """
 
     def applied(self, config, **kwargs):
         return isinstance(config.content, dict)
@@ -346,10 +346,10 @@ def reformat(self, config, **kwargs):
 
 
 class RenameSequencesToOverlayBy(BaseReformatStep):
-    '''
+    """
     Reformat passed report config content:
     "sequences": {...} -> "overlay_by": {...}
-    '''
+    """
 
     def applied(self, config, **kwargs):
         content = config.content
@@ -368,11 +368,11 @@ def reformat(self, config, **kwargs):
 
 
 class AllowMultipleSeriesArgs(BaseReformatStep):
-    '''
+    """
     Reformat passed report config content:
     "overlay_by": {"arg": "pkts", "percentage_base_value": 1} ->
     "overlay_by": [{"arg": "pkts", "percentage_base_value": 1}]
-    '''
+    """
 
     def applied(self, config, **kwargs):
         content = config.content
@@ -396,7 +396,7 @@ def reformat(self, config, **kwargs):
 
 
 class MergeDashboardSettings(BaseReformatStep):
-    '''
+    """
     Reformat passed global per_conf config content:
      - merge DASHBOARD_HEADER and DASHBOARD_PAYLOAD into DASHBOARD_COLUMNS,
      - for non-builtin column keys replace the key with the label value,
@@ -447,7 +447,7 @@ class MergeDashboardSettings(BaseReformatStep):
         }
     ],
     "DASHBOARD_RUNS_SORT": ["Session", "start"]
-    '''
+    """
 
     def applied(self, config, **kwargs):
         content = config.content
diff --git a/bublik/core/dashboard/services.py b/bublik/core/dashboard/services.py
index a73033cda..13ab8f93e 100644
--- a/bublik/core/dashboard/services.py
+++ b/bublik/core/dashboard/services.py
@@ -31,7 +31,7 @@ def get_dashboard_data(
         columns: dict | None = None,
         sort_config: list | None = None,
     ) -> dict:
-        '''
+        """
         Get dashboard data for a specific date.
 
         Args:
@@ -46,7 +46,7 @@ def get_dashboard_data(
 
         Raises:
             UnprocessableEntityError: if date format is invalid or config missing
-        '''
+        """
 
         # Get dashboard columns configuration (required) if not provided
         if columns is None:
@@ -120,7 +120,7 @@ def get_dashboard_data(
 
     @staticmethod
     def apply_dashboard_formatting(rows_data: list, columns: dict):
-        '''
+        """
         Apply formatting rules to dashboard row cells.
 
         Available formatters: 'percent'.
@@ -129,7 +129,7 @@ def apply_dashboard_formatting(rows_data: list, columns: dict):
             rows_data: List of row dictionaries with 'row_cells' key
             columns: Columns dict mapping keys to labels, payloads
                      and formatters
-        '''
+        """
         for row in rows_data:
             for key, col_settings in columns.items():
                 if key in row['row_cells']:
@@ -139,7 +139,7 @@ def apply_dashboard_formatting(rows_data: list, columns: dict):
 
     @staticmethod
     def sort_dashboard_rows(rows_data: list, sort_config: list) -> None:
-        '''
+        """
         Sort dashboard rows in-place by the configured columns.
 
         Args:
@@ -147,7 +147,7 @@ def sort_dashboard_rows(rows_data: list, sort_config: list) -> None:
             sort_config: List of column keys to sort by (e.g., ['start', 'total'])
 
         The rows_data list is modified in-place.
-        '''
+        """
 
         def prepare_sort_key(row: dict, key: str):
             if key == 'start':
@@ -170,12 +170,12 @@ def prepare_sort_key(row: dict, key: str):
 
     @staticmethod
     def _format_percent(data):
-        '''
+        """
         Format a value as a percentage.
 
         Args:
             data: Cell data (dict or list of dicts) with 'value' key
-        '''
+        """
 
         def format_value(item):
             value = item.get('value')
@@ -191,7 +191,7 @@ def format_value(item):
 
     @staticmethod
     def prepare_row_data(run, columns):
-        '''
+        """
         Prepare row cells data for a run.
 
         Args:
@@ -200,7 +200,7 @@ def prepare_row_data(run, columns):
 
         Returns:
             Dictionary with row cells data
-        '''
+        """
 
         livelog_check_run_timeout(run)
 
@@ -241,7 +241,7 @@ def prepare_row_data(run, columns):
 
     @staticmethod
     def get_latest_dashboard_date(project_id: int | None = None) -> str | None:
-        '''
+        """
         Get the most recent date with dashboard data.
 
         Args:
@@ -249,7 +249,7 @@ def get_latest_dashboard_date(project_id: int | None = None) -> str | None:
 
         Returns:
             Date string in 'yyyy-mm-dd' format, or None
-        '''
+        """
 
         date_meta = ConfigServices.getattr_from_global(
             GlobalConfigs.PER_CONF.name,
@@ -285,7 +285,7 @@ def validate_dashboard_settings(
         project_id: int | None = None,
         raise_on_error: bool = False,
     ) -> dict:
-        '''
+        """
         Validate all dashboard configuration settings.
 
         Args:
@@ -299,7 +299,7 @@ def validate_dashboard_settings(
 
         Raises:
             UnprocessableEntityError: if settings invalid and raise_on_error=True
-        '''
+        """
         errors = []
 
         # Get header (required setting)
@@ -329,7 +329,7 @@ def validate_dashboard_settings(
                 if diff:
                     errors.append(
                         f"DASHBOARD_RUNS_SORT doesn't match DASHBOARD_COLUMNS, "
-                        f"mismatch: {diff}",
+                        f'mismatch: {diff}',
                     )
             except Exception as e:
                 errors.append(f'DASHBOARD_RUNS_SORT: {e}')
@@ -343,7 +343,7 @@ def validate_dashboard_settings(
 
     @staticmethod
     def get_latest_run_date(project_id: int | None = None) -> str | None:
-        '''
+        """
         Alias for get_latest_dashboard_date() for backward compatibility.
 
         Args:
@@ -351,5 +351,5 @@ def get_latest_run_date(project_id: int | None = None) -> str | None:
 
         Returns:
             Date string in 'yyyy-mm-dd' format, or None
-        '''
+        """
         return DashboardService.get_latest_dashboard_date(project_id)
diff --git a/bublik/core/datetime_formatting.py b/bublik/core/datetime_formatting.py
index bbad3c9b7..e38abda19 100644
--- a/bublik/core/datetime_formatting.py
+++ b/bublik/core/datetime_formatting.py
@@ -11,14 +11,14 @@
 import pytz
 
 
-'''
+"""
 Use these (or create new for upcoming needs) functions
 whenever you need any datetime formattings.
 
 param ds: datetime string.
 param dt: datetime object.
 param date_str: date string.
-'''
+"""
 
 
 DISPLAY = settings.DATETIME_FORMATS['display']
diff --git a/bublik/core/fields.py b/bublik/core/fields.py
index ec60fecf5..82ebeb8fd 100644
--- a/bublik/core/fields.py
+++ b/bublik/core/fields.py
@@ -6,8 +6,8 @@
 
 class ModelMultipleChoiceField(forms.ModelMultipleChoiceField):
     def label_from_instance(self, obj):
-        '''
+        """
         This method receives a model object and
         return a string for representing it in the widget.
-        '''
+        """
         return obj.name
diff --git a/bublik/core/filter_backends.py b/bublik/core/filter_backends.py
index 1bc8a856d..7e18a22c4 100644
--- a/bublik/core/filter_backends.py
+++ b/bublik/core/filter_backends.py
@@ -6,14 +6,14 @@
 
 
 class AllDjangoFilterBackend(DjangoFilterBackend):
-    '''
+    """
     A filter backend to add filtering for all fields by default
-    '''
+    """
 
     def get_filterset_class(self, view, queryset=None):
-        '''
+        """
         Return the django-filters `FilterSet` used to filter the queryset.
-        '''
+        """
         filterset_class = getattr(view, 'filterset_class', None)
         filter_fields = getattr(view, 'filter_fields', None)
 
diff --git a/bublik/core/hash_system.py b/bublik/core/hash_system.py
index e36f05abc..4b3f51b47 100644
--- a/bublik/core/hash_system.py
+++ b/bublik/core/hash_system.py
@@ -15,12 +15,12 @@
 
 
 class HashedModelSerializer(ModelSerializer):
-    '''
+    """
     Allows validating and creating hashed instances.
 
     The order of data items as well as its nested list items order
     does not influence the hash produced by DeepHash class.
-    '''
+    """
 
     def hashable_data(self, data):
         hashable_fields = self.Meta.model.hashable
@@ -58,10 +58,10 @@ def create_hash(self, data, hasher=DEFAULT_HASHER):
             hashable_obj_data = self.hashable_data(obj_data)
             diff = DeepDiff(hashable_data, hashable_obj_data, ignore_order=True)
             if not diff:
-                '''Just Get the same object'''
+                """Just Get the same object"""
                 return data_hash
 
-            '''
+            """
             This code may be executed in the following cases:
             - creating new object a hash collision occurred;
             - there is a difference between the data passed for validation
@@ -75,7 +75,7 @@ def create_hash(self, data, hasher=DEFAULT_HASHER):
                 f"{data_hash}, but it represents different data: {obj_data}."
                 f"The diff is: {diff}. This is {salted_data['salt']} collision."
             )
-            '''
+            """
             salted_data['salt'] = salted_data.get('salt', 0) + 1
 
     def get_or_none(self, **kwargs):
diff --git a/bublik/core/history/services.py b/bublik/core/history/services.py
index 3e26cb27d..eab1462f8 100644
--- a/bublik/core/history/services.py
+++ b/bublik/core/history/services.py
@@ -36,9 +36,9 @@
 
 
 class HistoryService:
-    '''
+    """
     Expected number of parts when splitting key:value formatted test arguments.
-    '''
+    """
 
     EXPECTED_KEY_VALUE_PARTS = 2
 
@@ -67,7 +67,7 @@ def build_history_queryset(  # noqa: PLR0913
         verdict_expr: str | None = None,
         result_types: str | None = None,
     ):
-        '''
+        """
         Build history queryset with all filters applied.
 
         Args:
@@ -99,7 +99,7 @@ def build_history_queryset(  # noqa: PLR0913
 
         Raises:
             NotFoundError: if test name is invalid
-        '''
+        """
         query_delimiter = settings.QUERY_DELIMITER
         test_arg_delimiter = settings.KEY_VALUE_DELIMITER
 
@@ -169,7 +169,7 @@ def build_history_queryset(  # noqa: PLR0913
 
     @staticmethod
     def _validate_test_name(test_name: str) -> list[int]:
-        '''
+        """
         Validate test name and return test IDs.
 
         Args:
@@ -180,7 +180,7 @@ def _validate_test_name(test_name: str) -> list[int]:
 
         Raises:
             NotFoundError: if test name is invalid
-        '''
+        """
         test_ids = get_test_ids_by_name(test_name)
         if not test_ids:
             msg = 'Test with the specified name was not found'
@@ -205,7 +205,7 @@ def _apply_run_filters(  # noqa: PLR0913
         run_properties: str | None,
         query_delimiter: str,
     ) -> tuple[list[int], TestIterationResult]:
-        '''
+        """
         Apply run-level filters and return run IDs and filtered queryset.
 
         Args:
@@ -227,7 +227,7 @@ def _apply_run_filters(  # noqa: PLR0913
 
         Returns:
             Tuple of (run_ids_list, filtered_runs_queryset)
-        '''
+        """
         # Apply project filter if provided
         if project_id:
             runs_results = runs_results.filter(project_id=project_id)
@@ -282,7 +282,7 @@ def _apply_iteration_filters(
         query_delimiter: str,
         test_arg_delimiter: str,
     ) -> TestIterationResult:
-        '''
+        """
         Apply iteration-level filters to test results.
 
         Args:
@@ -296,7 +296,7 @@ def _apply_iteration_filters(
 
         Returns:
             Filtered test results queryset
-        '''
+        """
         # Filter by test name
         test_iterations = TestIteration.objects.filter(test__in=test_ids)
 
@@ -355,7 +355,7 @@ def _apply_result_filters(
         result_types: str | None,
         query_delimiter: str,
     ) -> TestIterationResult:
-        '''
+        """
         Apply result-level filters to test results.
 
         Args:
@@ -369,7 +369,7 @@ def _apply_result_filters(
 
         Returns:
             Filtered test results queryset
-        '''
+        """
         # Filter by result statuses
         if result_statuses:
             result_meta_ids = list(
@@ -416,7 +416,7 @@ def _apply_result_filters(
 
     @staticmethod
     def _finalize_queryset(test_results: TestIterationResult):
-        '''
+        """
         Apply final annotations and ordering to queryset.
 
         Args:
@@ -424,7 +424,7 @@ def _finalize_queryset(test_results: TestIterationResult):
 
         Returns:
             Annotated and ordered queryset
-        '''
+        """
         return (
             test_results.select_related('test_run', 'iteration')
             .annotate(
@@ -453,7 +453,7 @@ def _finalize_queryset(test_results: TestIterationResult):
 
     @staticmethod
     def prepare_results_data(test_results):
-        '''
+        """
         Prepare results data for response.
 
         Args:
@@ -461,7 +461,7 @@ def prepare_results_data(test_results):
 
         Returns:
             Tuple of (data dict, counts dict, runs_ids, iterations_ids, results_ids)
-        '''
+        """
         # Collect IDs
         runs_ids = set()
         iterations_ids = set()
@@ -506,7 +506,7 @@ def get_history(
         page_size: int | None = None,
         **filters,
     ) -> dict:
-        '''
+        """
         Get test history (linear format).
 
         Args:
@@ -520,7 +520,7 @@ def get_history(
 
         Raises:
             UnprocessableEntityError: if invalid parameters
-        '''
+        """
 
         # Build queryset
         test_results, from_date_obj, to_date_obj = HistoryService.build_history_queryset(
@@ -568,7 +568,7 @@ def get_history_grouped(
         page_size: int | None = None,
         **filters,
     ) -> dict:
-        '''
+        """
         Get test history grouped by iteration.
 
         Args:
@@ -582,7 +582,7 @@ def get_history_grouped(
 
         Raises:
             UnprocessableEntityError: if invalid parameters
-        '''
+        """
 
         # Build queryset
         test_results, from_date_obj, to_date_obj = HistoryService.build_history_queryset(
diff --git a/bublik/core/importruns/categorization.py b/bublik/core/importruns/categorization.py
index dfff4ade0..acfb1894b 100644
--- a/bublik/core/importruns/categorization.py
+++ b/bublik/core/importruns/categorization.py
@@ -15,12 +15,12 @@
 
 
 def categorize_metas(meta_data: MetaData, project_id) -> None:
-    '''
+    """
     Checks if all of the received Meta objects have already been categorized -
     which means if each Meta object has been added in MetaCategory.metas.
     If there is a Meta object that is not in proper MetaCategory.metas -
     the Meta object is added in MetaPattern.categories.metas.
-    '''
+    """
     logger = get_task_or_server_logger()
 
     logger.info('Checking what metas are categorized already.')
diff --git a/bublik/core/importruns/import_run.py b/bublik/core/importruns/import_run.py
index 4535160c0..65d05ddcf 100644
--- a/bublik/core/importruns/import_run.py
+++ b/bublik/core/importruns/import_run.py
@@ -185,8 +185,8 @@ def import_run(
         logs_base, suffix_url = extract_logs_base(run_source_url, project.id)
         if not suffix_url:
             error_msg = (
-                'run URL doesn\'t match any of the logs bases URIs specified '
-                'in the project\'s references configuration'
+                "run URL doesn't match any of the logs bases URIs specified "
+                "in the project's references configuration"
             )
             logs_bases = ConfigServices.getattr_from_global(
                 GlobalConfigs.REFERENCES.name,
@@ -203,7 +203,7 @@ def import_run(
         # Filter out runs that don't fit the specified interval
         if not meta_data.check_run_period(date_from, date_to):
             msg = (
-                'run isn\'t satisfy '
+                "run isn't satisfy "
                 f'the period {date_from.to_date_string()} - '
                 f'{date_to.to_date_string()}'
             )
diff --git a/bublik/core/importruns/live/context.py b/bublik/core/importruns/live/context.py
index 83092057d..ab839d626 100644
--- a/bublik/core/importruns/live/context.py
+++ b/bublik/core/importruns/live/context.py
@@ -40,7 +40,7 @@
 
 
 class LiveLogError(Exception):
-    '''Exceptions related to live log import.'''
+    """Exceptions related to live log import."""
 
     def __init__(self, msg, **kwargs):
         self.data = kwargs
@@ -54,28 +54,28 @@ def to_response(self):
 
 
 class LLInvalidInputError(LiveLogError):
-    '''User-supplied data is invalid.'''
+    """User-supplied data is invalid."""
 
     STATUS = status.HTTP_400_BAD_REQUEST
 
 
 class LLInternalError(LiveLogError):
-    '''An internal error has occured during request processing.'''
+    """An internal error has occured during request processing."""
 
     STATUS = status.HTTP_500_INTERNAL_SERVER_ERROR
 
 
 class LLNotImplementedError(LiveLogError):
-    '''An internal error has occured during request processing.'''
+    """An internal error has occured during request processing."""
 
     STATUS = status.HTTP_501_NOT_IMPLEMENTED
 
 
 class NodeIDConverter:
-    '''
+    """
     Track node ID to TestIterationResult ID mapping for easy artifact
     message processing.
-    '''
+    """
 
     HISTORY_SIZE = 20
 
@@ -95,7 +95,7 @@ def get_result_id(self, target_node_id):
 
 
 class TestStackItem:
-    '''Description of the currently running entity in Bublik terms.'''
+    """Description of the currently running entity in Bublik terms."""
 
     def __init__(
         self,
@@ -117,10 +117,10 @@ def __init__(
 
 
 class LiveLogContext:
-    '''
+    """
     Context that should be preserved between the heartbeats of TE
     log streaming protocol.
-    '''
+    """
 
     # Additional time to allow a request to reach Bublik
     # (and let Bublik process other tasks)
@@ -234,7 +234,7 @@ def __init__(self, data):
         self.node_conv = NodeIDConverter()
 
     def serialize(self):
-        '''Prepare the stack to be cached, deflate model objects.'''
+        """Prepare the stack to be cached, deflate model objects."""
         if isinstance(self.run, int):
             return
 
@@ -245,7 +245,7 @@ def serialize(self):
             item.result = item.result.id
 
     def deserialize(self):
-        '''Inflate model objects after the stack was extracted from cache.'''
+        """Inflate model objects after the stack was extracted from cache."""
         if isinstance(self.run, TestIterationResult):
             return
 
@@ -279,12 +279,12 @@ def peek_stack(self):
         return self.test_stack[-1]
 
     def ts_microstep(self):
-        '''
+        """
         Increase the last timestamp by a microsecond.
 
         This function is used to ensure that all LOST iteration results have
         unique timestamps.
-        '''
+        """
         self.last_ts += timedelta(microseconds=1)
         return self.last_ts
 
@@ -366,11 +366,11 @@ def on_item_exit(plan_item):
         return on_item_enter, on_item_exit
 
     def advance_plan(self, target_plan_id, stop_at_start, target_dt):
-        '''
+        """
         Fast-forward test execution state to the point where target_plan_id
         is the plan id of the next expected test_start event (or test_end,
         depending on the value of the stop_at_start parameter).
-        '''
+        """
 
         on_item_enter, on_item_exit = self.plan_skip_handlers()
         if on_item_enter is not None and on_item_exit is not None:
@@ -389,7 +389,7 @@ def advance_plan(self, target_plan_id, stop_at_start, target_dt):
                 self.plan_tracker.next_event()
 
     def fatal_error(self):
-        '''Finish the import after a fatal error.'''
+        """Finish the import after a fatal error."""
         # Finish everything that's currently running
         for item in reversed(self.test_stack):
             self.ts_microstep()
@@ -581,7 +581,7 @@ def handle_test_end(self, event):
         self.plan_tracker.next_event()
 
     def feed(self, events):
-        '''Process events produced by TE.'''
+        """Process events produced by TE."""
 
         for event in events:
             if 'type' not in event:
@@ -606,7 +606,7 @@ def feed(self, events):
                     )
 
     def finish(self, data):
-        '''Initialize import using TE log streaming protocol.'''
+        """Initialize import using TE log streaming protocol."""
         if 'ts' not in data:
             msg = 'timestamp is required'
             raise LLInvalidInputError(msg)
diff --git a/bublik/core/importruns/live/plan_tracking.py b/bublik/core/importruns/live/plan_tracking.py
index 1bcb91b38..a5f579199 100644
--- a/bublik/core/importruns/live/plan_tracking.py
+++ b/bublik/core/importruns/live/plan_tracking.py
@@ -5,12 +5,12 @@
 
 
 class PlanItem:
-    '''
+    """
     Description of an execution plan item.
 
     While this class contains enough information to traverse the whole
     execution plan, using a PlanTracker is advised.
-    '''
+    """
 
     def __init__(self, item, parent=None):
         self.id = 0
@@ -57,10 +57,10 @@ def tests_num(self):
         return tests_num
 
     def tree_nodes_num(self):
-        '''
+        """
         This function returns the number of nodes in the tree, whose root is
         the current node (self).
-        '''
+        """
         if not self.children:
             return 1
 
@@ -71,11 +71,11 @@ def tree_nodes_num(self):
         return tree_nodes_num
 
     def tests_num_prologue(self, tests_nums_prologues, plan_id):
-        '''
+        """
         This function returns a dictionary whose keys are the 'plan_id' of the prologues,
         and the values are the number of tests that will be skipped if the prologue
         is skipped or failed.
-        '''
+        """
         if self.has_prologue:
             prologue_tests_num = 0
             for child in self.children:
@@ -99,9 +99,9 @@ def tests_num_prologue(self, tests_nums_prologues, plan_id):
 
 
 class PlanStackItem:
-    '''
+    """
     This class contains aux data required to traverse the execution plan.
-    '''
+    """
 
     def __init__(self, plan_item):
         self.item = plan_item
@@ -116,7 +116,7 @@ def next_child(self):
 
 
 class PlanTracker:
-    '''High-level interface to tracking test execution.'''
+    """High-level interface to tracking test execution."""
 
     def do_nothing(self, x):
         return None
@@ -126,7 +126,7 @@ def __init__(self, root_item):
         self.next_id = 1
 
     def next_event(self):
-        '''Advance one step through the plan.'''
+        """Advance one step through the plan."""
         if len(self.stack) == 0:
             return
 
@@ -144,22 +144,22 @@ def next_event(self):
             self.stack.append(child)
 
     def peek_event(self):
-        '''Return the next event, do not advance.'''
+        """Return the next event, do not advance."""
         if len(self.stack) == 0:
             return None
 
         return self.stack[-1].item, self.stack[-1].running
 
     def finished(self):
-        '''Has test execution finished according to the plan?'''
+        """Has test execution finished according to the plan?"""
         return self.peek_event() is None
 
     def skip_until(self, target_id, until_start, on_enter=None, on_exit=None):
-        '''
+        """
         Advance through the plan until
             1. (if until_start is True) we are about to enter the target item;
             2. (if until_start is False) we have just exited from the target item.
-        '''
+        """
 
         def reached_goal():
             item, enter = event
@@ -176,7 +176,7 @@ def reached_goal():
             event = self.peek_event()
 
     def skip_all(self, on_enter=None, on_exit=None):
-        '''Advance through the plan until the end.'''
+        """Advance through the plan until the end."""
         event = self.peek_event()
         while event is not None:
             item, enter = event
diff --git a/bublik/core/importruns/milog.py b/bublik/core/importruns/milog.py
index 72da72510..76c7dd64c 100644
--- a/bublik/core/importruns/milog.py
+++ b/bublik/core/importruns/milog.py
@@ -26,10 +26,10 @@
 
 
 class Saver:
-    '''If a class describes the last level of nesting, it probably wants
+    """If a class describes the last level of nesting, it probably wants
     to save data to the database.  This class must be a child of
     the Saver class, It should also implement the save() method.
-    '''
+    """
 
     single_measurements: ClassVar[list] = []
     list_measurements: ClassVar[list] = []
@@ -50,10 +50,10 @@ def check_metas_in_measurement(measurement, metas_ids):
 
 
 class InstanceLevel:
-    '''The MI log consists of several levels of nesting. The nesting level
+    """The MI log consists of several levels of nesting. The nesting level
     is what is inside the parentheses.
     This class is the base class for describing the level.
-    '''
+    """
 
     def __init__(self, data, meta_type):
         self.data = []
diff --git a/bublik/core/importruns/source/execution.py b/bublik/core/importruns/source/execution.py
index d49a804ef..cbfdc19df 100644
--- a/bublik/core/importruns/source/execution.py
+++ b/bublik/core/importruns/source/execution.py
@@ -251,24 +251,24 @@ def incremental_import(run_log, project_id, meta_data, run_completed, force):
     if run_log.get('iters') is not None:
         handle_iterations(run_log, run, project_id, tests_nums_prologues)
         logger.info(
-            f"the number of handled iterations is {handle_iteration.counter['iter_obj']}",
+            f'the number of handled iterations is {handle_iteration.counter["iter_obj"]}',
         )
         logger.info(
             'the number of created iteration objects is '
-            f"{handle_iteration.counter['created_iter_obj']}",
+            f'{handle_iteration.counter["created_iter_obj"]}',
         )
         logger.info(
             f'handling measurements during handling iterations took ['
             f'{HandlerArtifacts.handle_meas_time}]',
         )
-        logger.info(f"the number of handled measurements is {EntryLevel.counter['meas_obj']}")
+        logger.info(f'the number of handled measurements is {EntryLevel.counter["meas_obj"]}')
         logger.info(
             'the number of created measurement objects is '
-            f"{EntryLevel.counter['created_meas_obj']}",
+            f'{EntryLevel.counter["created_meas_obj"]}',
         )
         logger.info(
             'the number of created measurement result objects is '
-            f"{EntryLevel.counter['created_meas_res_obj']}",
+            f'{EntryLevel.counter["created_meas_res_obj"]}',
         )
     else:
         logger.info('there is no iterations in this run. Skip handling.')
diff --git a/bublik/core/importruns/source/run_traversal.py b/bublik/core/importruns/source/run_traversal.py
index 5d4b3d2b3..d23741934 100644
--- a/bublik/core/importruns/source/run_traversal.py
+++ b/bublik/core/importruns/source/run_traversal.py
@@ -127,9 +127,9 @@ def __find_runs(self, url):
 
         ast = BeautifulSoup(markup=html, features='html.parser')
         if ast.find(
-            lambda t: t.name == 'a'
-            and t.string
-            and t.string.strip().lower() == 'trc_compromised.js',
+            lambda t: (
+                t.name == 'a' and t.string and t.string.strip().lower() == 'trc_compromised.js'
+            ),
         ):
             raise RunCompromisedError
 
@@ -139,10 +139,12 @@ def __find_runs(self, url):
 
         # NOTE: the parser relies on links to directories ending with a slash "/"
         for node in ast.find_all(
-            lambda t: t.name == 'a'
-            and hasattr(t, 'href')
-            and not re.match(r'(\./)?\.\./?', t['href'])
-            and t['href'].endswith('/'),
+            lambda t: (
+                t.name == 'a'
+                and hasattr(t, 'href')
+                and not re.match(r'(\./)?\.\./?', t['href'])
+                and t['href'].endswith('/')
+            ),
         ):
             a_href = node['href'].strip()
             url_next = urljoin(url + '/', a_href)
diff --git a/bublik/core/importruns/telog.py b/bublik/core/importruns/telog.py
index 6101d9237..bceb46353 100644
--- a/bublik/core/importruns/telog.py
+++ b/bublik/core/importruns/telog.py
@@ -11,9 +11,9 @@
 
 
 class ConverterError(Exception):
-    '''
+    """
     Converter Error exception class that incapsulates internal errors
-    '''
+    """
 
     def __init__(self, log_type, log_path='', exception='', action='unable to convert'):
         self.action = action
@@ -27,10 +27,10 @@ def __str__(self):
 
 
 class LogConverter:
-    '''
+    """
     Abstract log converter that converts path_in into path_out
     by executing an external conversion command.
-    '''
+    """
 
     def __init__(self, log_type, path_in=None, path_out=None):
         assert log_type
@@ -58,9 +58,7 @@ def convert(self):
             if proc.wait() != 0:
                 output, error = proc.communicate()
                 logger.error(
-                    f'Failed conversion command: {cmd}\n'
-                    f'Output: {output}\n'
-                    f'Error: {error}',
+                    f'Failed conversion command: {cmd}\nOutput: {output}\nError: {error}',
                 )
                 raise ConverterError(
                     self.log_type,
@@ -75,9 +73,9 @@ def convert(self):
 
 
 class GZipLog(LogConverter):
-    '''
+    """
     Class to decompress GZip files.
-    '''
+    """
 
     FMT_GZIP_DECOMPRESS = "gzip -d -k '{path_in}' -c > '{path_out}'"
 
@@ -94,9 +92,9 @@ def convert_cmd(self):
 
 
 class BZip2Log(LogConverter):
-    '''
+    """
     Class to decompress BZip2 files.
-    '''
+    """
 
     FMT_BZIP2_DECOMPRESS = "bzip2 -d -k '{path_in}' -c > '{path_out}'"
 
@@ -116,9 +114,9 @@ def convert_cmd(self):
 
 
 class XZLog(LogConverter):
-    '''
+    """
     Class to decompress XZ files.
-    '''
+    """
 
     FMT_XZ_DECOMPRESS = "xz -d -k '{path_in}' -c > '{path_out}'"
 
@@ -135,10 +133,10 @@ def convert_cmd(self):
 
 
 class XMLLog(LogConverter):
-    '''
+    """
     This class keeps a temporary file for XML log and provides interfaces
     to convert this log.
-    '''
+    """
 
     FMT_XML_PARSER = "{path_xml_parser} '{path_in}' > '{path_out}'"
 
@@ -160,10 +158,10 @@ def convert_cmd(self):
 
 
 class RawLog(LogConverter):
-    '''
+    """
     This class keeps a temporary file for raw log and provides interfaces
     to convert this log.
-    '''
+    """
 
     FMT_RGT_CONV = "te-trc-log --mi-meta '{path_in}' '{path_out}'"
 
@@ -179,10 +177,10 @@ def convert_cmd(self):
 
 
 class RawLogBundle(LogConverter):
-    '''
+    """
     This class keeps a temporary file for raw log bundle and provides
     interfaces to convert this log.
-    '''
+    """
 
     FMT_RGT_LOG_ORIGINAL = (
         "rgt-log-bundle-get-original --bundle='{path_in}' --raw-log='{path_out}'"
@@ -203,10 +201,10 @@ def convert_cmd(self):
 
 
 class JSONLog:
-    '''
+    """
     This class keeps a temporary file for JSON log and provides interfaces
     to unpack and load this log.
-    '''
+    """
 
     def __init__(self, process_dir=None, json_filename='log.json'):
         self.path_json_log = None
diff --git a/bublik/core/job_task/services.py b/bublik/core/job_task/services.py
index f8daf3828..cc7510fdb 100644
--- a/bublik/core/job_task/services.py
+++ b/bublik/core/job_task/services.py
@@ -60,7 +60,7 @@ def list_job_task_queryset():
 
     @staticmethod
     def _extract_error(event_logs: list[dict]) -> str | None:
-        '''
+        """
         Extract error message from event logs if present.
 
         Args:
@@ -68,7 +68,7 @@ def _extract_error(event_logs: list[dict]) -> str | None:
 
         Returns:
             Extracted error string, or None
-        '''
+        """
         pattern = r'--\s*Error:\s*(.*?)(?:\s*--|$)'
         for event_log in event_logs:
             msg = event_log.get('msg', '')
@@ -78,7 +78,7 @@ def _extract_error(event_logs: list[dict]) -> str | None:
 
     @staticmethod
     def get_tasks_by_job(job_id: int) -> list[TaskSummary]:
-        '''
+        """
         Get all task execution results for a given job ID.
 
         Args:
@@ -89,7 +89,7 @@ def get_tasks_by_job(job_id: int) -> list[TaskSummary]:
 
         Raises:
             NotFoundError: if no tasks found for the given job
-        '''
+        """
         task_results = list(
             JobTaskExecutionService.list_job_task_queryset()
             .filter(job_id=job_id)
@@ -110,7 +110,7 @@ def get_tasks_by_job(job_id: int) -> list[TaskSummary]:
 
     @staticmethod
     def list_tasks(filtered_queryset) -> list[TaskExecutionResult]:
-        '''
+        """
         Annotate and return a list of task execution results with
         timing, event logs, and extracted error messages.
 
@@ -122,7 +122,7 @@ def list_tasks(filtered_queryset) -> list[TaskExecutionResult]:
 
         Raises:
             NotFoundError: if no tasks match the given parameters
-        '''
+        """
         task_results = list(
             filtered_queryset.order_by('-id')
             .annotate(
diff --git a/bublik/core/log/services.py b/bublik/core/log/services.py
index ead98b8b8..f3b61a057 100644
--- a/bublik/core/log/services.py
+++ b/bublik/core/log/services.py
@@ -23,7 +23,7 @@ def get_json_log_urls(
         page: int | None = None,
         request_origin: str | None = None,
     ) -> dict:
-        '''
+        """
         Get JSON log and attachments URLs for a result.
 
         Args:
@@ -36,7 +36,7 @@ def get_json_log_urls(
 
         Raises:
             UnprocessableEntityError: if result not found or invalid page parameter
-        '''
+        """
         result = ResultService.get_result(result_id)
         run_source_link = get_sources(result)
 
@@ -81,7 +81,7 @@ def get_json_log_urls(
 
     @staticmethod
     def get_html_log_url(result_id: int) -> str | None:
-        '''
+        """
         Get HTML log URL for a result.
 
         Args:
@@ -92,13 +92,13 @@ def get_html_log_url(result_id: int) -> str | None:
 
         Raises:
             UnprocessableEntityError: if result not found
-        '''
+        """
         result = ResultService.get_result(result_id)
         return get_result_log(result)
 
     @staticmethod
     def fetch_log_content(url: str, allow_not_found: bool = True) -> dict | None:
-        '''
+        """
         Fetch JSON content from URL.
 
         Args:
@@ -109,7 +109,7 @@ def fetch_log_content(url: str, allow_not_found: bool = True) -> dict | None:
 
         Raises:
             UnprocessableEntityError: if URL is missing
-        '''
+        """
         if not url:
             msg = 'URL parameter is missing'
             raise UnprocessableEntityError(msg)
@@ -137,7 +137,7 @@ def fetch_log_content(url: str, allow_not_found: bool = True) -> dict | None:
 
     @staticmethod
     def get_log_json(result_id: int, page: int | None = None) -> dict:
-        '''
+        """
         Fetch and return actual JSON log content.
 
         Args:
@@ -152,7 +152,7 @@ def get_log_json(result_id: int, page: int | None = None) -> dict:
 
         Raises:
             UnprocessableEntityError: if result not found or invalid parameters
-        '''
+        """
         # Get URLs (without proxy for direct fetching)
         urls = LogService.get_json_log_urls(result_id, page, request_origin=None)
 
diff --git a/bublik/core/logging.py b/bublik/core/logging.py
index 8db536e21..0eefffb3e 100644
--- a/bublik/core/logging.py
+++ b/bublik/core/logging.py
@@ -29,7 +29,7 @@ def __init__(self, task_id, *args, **kwargs):
 
 
 def get_task_or_server_logger():
-    '''A helper function to create function specific logger lazily.'''
+    """A helper function to create function specific logger lazily."""
     # Every logger in the celery package inherits from the "celery" logger,
     # and every task logger inherits from the "celery.task" logger.
     task_id = os.getenv('TASK_ID', None)
diff --git a/bublik/core/mail.py b/bublik/core/mail.py
index fbf4ed505..ae677c90f 100644
--- a/bublik/core/mail.py
+++ b/bublik/core/mail.py
@@ -21,14 +21,14 @@ def send_importruns_failed_mail(
     source=None,
     add_to_message=None,
 ):
-    '''
+    """
     Sends mails to per-project watchers and Bublik admins.
 
     Parameter @requesting_host is a Bublik host where importruns failed.
     Parameter @item_id can represent either run id or async task id of importruns.
     Parameter @source is a link through a run was imported.
     Parameter @add_to_message is a string added to the default message.
-    '''
+    """
 
     email_from = getattr(settings, 'EMAIL_FROM', None)
     recipients = ConfigServices.getattr_from_global(
@@ -72,9 +72,9 @@ def _make_hash_value(self, user, timestamp):
 
 
 def send_verification_link_mail(request, user):
-    '''
+    """
     Sends an email to the user with a link that activates his account when clicked.
-    '''
+    """
     from_email = getattr(settings, 'EMAIL_FROM', None)
 
     email_verification_token = EmailVerificationTokenGenerator()
diff --git a/bublik/core/measurement/filters.py b/bublik/core/measurement/filters.py
index f8ff019ca..c842438af 100644
--- a/bublik/core/measurement/filters.py
+++ b/bublik/core/measurement/filters.py
@@ -9,10 +9,10 @@
 
 
 class MeasurementResultFilter(filters.BaseFilterBackend):
-    '''To use this filter, you must define search_fields in the view.
+    """To use this filter, you must define search_fields in the view.
     Only these fields will be filtered. The result field will be filtered
     by default, and you don't need to specify it.
-    '''
+    """
 
     search_field_to_meta_type = {
         'tool': 'tool',
diff --git a/bublik/core/measurement/representation.py b/bublik/core/measurement/representation.py
index c2e761b0f..81975743f 100644
--- a/bublik/core/measurement/representation.py
+++ b/bublik/core/measurement/representation.py
@@ -20,10 +20,10 @@
 
 
 class ChartViewBuilder:
-    '''
+    """
     Considering the purpose of ChartView model to describe views of two measurements
     on a single graph ChartViewBuilder provides the interface to do this.
-    '''
+    """
 
     REPR_KEYS: typing.ClassVar[list] = [
         'id',
@@ -42,10 +42,10 @@ def __init__(self, y_measurement: Measurement, view: View = None):
         self.subtitle = self.get_measurement_chart_label()
 
     def convert_dataset(self):
-        '''
+        """
         Convert the chart dataset from a dictionary list to a list of lists
         (more convinient for UI).
-        '''
+        """
         keys = next(iter(self.dataset)).keys()
         self.dataset = [point.values() for point in self.dataset]
         self.dataset.insert(0, keys)
@@ -60,11 +60,11 @@ def by_lines(
         y_meas_res_list: MeasurementResultList,
         x_meas_res_list: MeasurementResultList = None,
     ):
-        '''
+        """
         This method allows you to obtain data for plotting the dependence of the Y measurement
         results on the X measurement results (on the ordinal number of the measurement value
         in the sequence of results in the absence of measurement X).
-        '''
+        """
         axis_x_measurement = x_meas_res_list.measurement if x_meas_res_list else None
         self.axis_x = AxisRepresentationBuilder(axis_x_measurement).to_representation()
         self.axis_y = AxisRepresentationBuilder(self.measurement).to_representation()
@@ -87,12 +87,12 @@ def by_points(cls, cvs: QuerySet[ChartView]):
         pass
 
     def by_measurement_results(self, mmrs):
-        '''
+        """
         This method allows you to obtain data for plotting changes in measurement
         results over iterations from the passed range. In addition to the values,
         each point also contains the IDs of the run, result, and iteration in order
         to be able to switch to other views.
-        '''
+        """
         self.axis_x = AxisRepresentationBuilder(
             label='Start of measurement test',
             key='start',
@@ -116,9 +116,9 @@ def by_measurement_results(self, mmrs):
         return self
 
     def set_merge_key_value(self, merge_mm_key: list[str]):
-        '''
+        """
         Sets the value of the merge key based on the passed measurement attributes.
-        '''
+        """
         measurement_data = self.measurement.representation()
         self.merge_key_value = [
             measurement_data[key] for key in measurement_data if key in merge_mm_key
@@ -157,11 +157,11 @@ def get_measurement_chart_label(self, series_args_label=None):
 
 
 class ReportRecordBuilder(ChartViewBuilder):
-    '''
+    """
     Objects of this class contain the information necessary to display the passed points
     - the results of the passed measurement - on a chart and/or in a table in accordance
     with the passed configuration.
-    '''
+    """
 
     REPR_KEYS: typing.ClassVar[list] = [
         'type',
@@ -271,10 +271,10 @@ def get_series(self, record_points, series_args_vals_labels):
 
 
 class ReportRecordDataBuilder:
-    '''
+    """
     This class allows you to get data for building tables and charts
     based on the passed series.
-    '''
+    """
 
     def __init__(self, series):
         self.series = series
@@ -283,9 +283,9 @@ def sort_points_series(self):
         return {sga: dict(sorted(points.items())) for sga, points in self.series.items()}
 
     def normalize_series(self, axis_x_data):
-        '''
+        """
         Align all series to the same x-axis by filling missing points with empty values.
-        '''
+        """
         for series_arg, series in self.series.items():
             for axis_x_val in set(axis_x_data.get('values', [])) - set(series.keys()):
                 self.series[series_arg][axis_x_val] = {'y_value': None}
@@ -307,9 +307,9 @@ def get_record_data(self, axis_x_data):
 
 
 class ReportChartBuilder:
-    '''
+    """
     This class describes the report chart.
-    '''
+    """
 
     REPR_KEYS: typing.ClassVar[list] = [
         'warnings',
@@ -337,10 +337,10 @@ def get_axis_x_values(self, series):
         return {axis_x for points in series.values() for axis_x in points}
 
     def get_chart_series(self, series):
-        '''
+        """
         Leave only the points in the series that have the numeric value
         of the x-axis argument.
-        '''
+        """
         return {
             sga: {
                 x: point_data for x, point_data in points.items() if isinstance(x, (int, float))
@@ -361,9 +361,9 @@ def get_warnings(self, series):
 
 
 class ReportTableBuilder:
-    '''
+    """
     This class describes the report table.
-    '''
+    """
 
     REPR_KEYS: typing.ClassVar[list] = [
         'warnings',
@@ -390,18 +390,18 @@ def representation(self):
         }
 
     def sort_series(self, series, base_series_label):
-        '''
+        """
         Make the base series first.
-        '''
+        """
         return {
             base_series_label: series[base_series_label],
             **{k: v for k, v in series.items() if k != base_series_label},
         }
 
     def get_percentages(self, series, base_series_label):
-        '''
+        """
         Calculate the gain relative to the base series.
-        '''
+        """
         percentages = {}
         self.formatters = {}
         base_series = series.pop(base_series_label)
@@ -423,9 +423,9 @@ def get_percentages(self, series, base_series_label):
         return percentages
 
     def get_table_series(self, series, base_series_label):
-        '''
+        """
         Add series with percentages.
-        '''
+        """
         table_series = copy.deepcopy(series)
         if base_series_label:
             if base_series_label in series:
diff --git a/bublik/core/measurement/services.py b/bublik/core/measurement/services.py
index 3940a7301..b2b449ffc 100644
--- a/bublik/core/measurement/services.py
+++ b/bublik/core/measurement/services.py
@@ -172,17 +172,17 @@ def grouper_by_measurement(cv):
 class MeasurementService:
     @staticmethod
     def list_measurements():
-        '''
+        """
         Get all measurements.
 
         Returns:
             QuerySet of Measurement objects with prefetched metas
-        '''
+        """
         return Measurement.objects.prefetch_related('metas').all()
 
     @staticmethod
     def get_measurement(measurement_id: int) -> Measurement:
-        '''
+        """
         Get a measurement by ID.
 
         Args:
@@ -193,7 +193,7 @@ def get_measurement(measurement_id: int) -> Measurement:
 
         Raises:
             NotFoundError: if measurement not found
-        '''
+        """
         try:
             return Measurement.objects.get(id=measurement_id)
         except ObjectDoesNotExist as e:
@@ -202,7 +202,7 @@ def get_measurement(measurement_id: int) -> Measurement:
 
     @staticmethod
     def get_trend_charts(result_ids: list[int]) -> list:
-        '''
+        """
         Get measurement trend charts for multiple result IDs.
 
         Groups measurements by measurement_group_key and builds chart representations.
@@ -215,7 +215,7 @@ def get_trend_charts(result_ids: list[int]) -> list:
 
         Raises:
             ValidationError: if result_ids is empty
-        '''
+        """
         if not result_ids:
             msg = 'No result IDs specified'
             raise ValidationError(msg)
@@ -234,7 +234,7 @@ def get_trend_charts(result_ids: list[int]) -> list:
 
     @staticmethod
     def get_measurements_by_result_ids(result_ids: list[int]) -> list[dict]:
-        '''
+        """
         Get measurements with parameters for each result ID.
 
         For each result, includes:
@@ -250,7 +250,7 @@ def get_measurements_by_result_ids(result_ids: list[int]) -> list[dict]:
 
         Raises:
             ValidationError: if result_ids is empty
-        '''
+        """
         if not result_ids:
             msg = 'No result IDs specified'
             raise ValidationError(msg)
@@ -276,7 +276,7 @@ def get_measurements_by_result_ids(result_ids: list[int]) -> list[dict]:
                 # Unify expected to fail here since
                 # Strings nested within an f-string cannot use the same quote character
                 # as the f-string prior to Python 3.12
-                chart['id'] = f"{test_result.id}_{chart['id']}"
+                chart['id'] = f'{test_result.id}_{chart["id"]}'
                 measurement_series_charts.append(chart)
 
             measurement_series_charts_by_result.append(
diff --git a/bublik/core/pagination_helpers.py b/bublik/core/pagination_helpers.py
index 2f48f79d3..fd38b7702 100644
--- a/bublik/core/pagination_helpers.py
+++ b/bublik/core/pagination_helpers.py
@@ -35,7 +35,7 @@ def paginate_queryset(
         page: int | str | None = None,
         page_size: int | str | None = None,
     ) -> dict:
-        '''
+        """
         Apply pagination to a queryset and return paginated result.
 
         Args:
@@ -48,7 +48,7 @@ def paginate_queryset(
 
         Raises:
             ValidationError: if page/page_size are invalid
-        '''
+        """
         default_page = 1
         default_page_size = 25
         max_page_size = 10000
diff --git a/bublik/core/project/services.py b/bublik/core/project/services.py
index 1b7cc6971..04d6020e6 100644
--- a/bublik/core/project/services.py
+++ b/bublik/core/project/services.py
@@ -19,27 +19,27 @@
 class ProjectService:
     @staticmethod
     def list_projects_queryset():
-        '''
+        """
         Get all projects queryset ordered by ID.
 
         Returns:
             QuerySet of Project objects
-        '''
+        """
         return models.Project.objects.order_by('id')
 
     @staticmethod
     def list_projects() -> list[dict]:
-        '''
+        """
         List all projects.
 
         Returns:
             List of dictionaries with project id and name
-        '''
+        """
         return list(ProjectService.list_projects_queryset().values('id', 'name'))
 
     @staticmethod
     def get_project_instance(project_id: int | str) -> models.Project:
-        '''
+        """
         Get a single project model instance by ID.
 
         Args:
@@ -50,7 +50,7 @@ def get_project_instance(project_id: int | str) -> models.Project:
 
         Raises:
             NotFoundError: if project not found
-        '''
+        """
         try:
             return models.Project.objects.get(id=project_id)
         except (ObjectDoesNotExist, TypeError, ValueError) as e:
@@ -59,7 +59,7 @@ def get_project_instance(project_id: int | str) -> models.Project:
 
     @staticmethod
     def get_project(project_id: int | str) -> dict:
-        '''
+        """
         Get a single project by ID.
 
         Args:
@@ -70,13 +70,13 @@ def get_project(project_id: int | str) -> dict:
 
         Raises:
             NotFoundError: if project not found
-        '''
+        """
         project = ProjectService.get_project_instance(project_id)
         return {'id': project.id, 'name': project.name}
 
     @staticmethod
     def create_project(data: dict) -> models.Project:
-        '''
+        """
         Create a project.
 
         Args:
@@ -84,7 +84,7 @@ def create_project(data: dict) -> models.Project:
 
         Returns:
             Created Project model instance
-        '''
+        """
         serializer = ProjectSerializer(data=data)
         serializer.is_valid(raise_exception=True)
         return serializer.save()
@@ -95,7 +95,7 @@ def update_project(
         data: dict,
         partial: bool = False,
     ) -> models.Project:
-        '''
+        """
         Update a project.
 
         Args:
@@ -108,7 +108,7 @@ def update_project(
 
         Raises:
             NotFoundError: if project not found
-        '''
+        """
         project = ProjectService.get_project_instance(project_id)
         serializer = ProjectSerializer(project, data=data, partial=partial)
         serializer.is_valid(raise_exception=True)
@@ -116,7 +116,7 @@ def update_project(
 
     @staticmethod
     def delete_project(project_id: int | str) -> None:
-        '''
+        """
         Delete a project.
 
         Args:
@@ -125,7 +125,7 @@ def delete_project(project_id: int | str) -> None:
         Raises:
             NotFoundError: if project not found
             ValidationError: if project has linked runs
-        '''
+        """
         project = ProjectService.get_project_instance(project_id)
         if project.testiterationresult_set.exists():
             msg = 'Unable to delete: there are runs linked to this project'
@@ -266,12 +266,12 @@ class ProjectBadgeService:
 
     @staticmethod
     def _text_width(text):
-        '''Return approximate pixel width of text rendered in Verdana 11px.'''
+        """Return approximate pixel width of text rendered in Verdana 11px."""
         return sum(ProjectBadgeService._WIDTHS.get(c, 6.0) for c in text)
 
     @staticmethod
     def render(label, value, color, label_color='#555') -> str:
-        '''Generate an SVG badge matching shields.io flat style.'''
+        """Generate an SVG badge matching shields.io flat style."""
         label_tw = ProjectBadgeService._text_width(label)
         value_tw = ProjectBadgeService._text_width(value)
 
@@ -305,7 +305,7 @@ def render(label, value, color, label_color='#555') -> str:
 
     @staticmethod
     def get_latest_run(project):
-        '''Return the most recent top-level run for the given project, or None.'''
+        """Return the most recent top-level run for the given project, or None."""
         return (
             TestIterationResult.objects.filter(project=project, test_run__isnull=True)
             .order_by('-start')
diff --git a/bublik/core/report/components.py b/bublik/core/report/components.py
index 1e94f502d..2d5e6bea7 100644
--- a/bublik/core/report/components.py
+++ b/bublik/core/report/components.py
@@ -6,7 +6,7 @@
 from bublik.core.utils import parse_number, unordered_group_by
 
 
-'''
+"""
 The report has four levels of nesting:
 1. Test level. It contains test common arguments and enabled views.
 2. Arguments values level. It contains arguments with their values.
@@ -15,20 +15,20 @@
 4. Record level. It contains records (tables and/or charts with measurement results).
    The points in each record are grouped into series based on the values of specific
    arguments.
-'''
+"""
 
 
 class ReportPoint:
-    '''
+    """
     This class describes the points of records and the function that allows you to group
     them by the value of the passed attribute.
-    '''
+    """
 
     def __init__(self, mmr, common_args, report_config):
-        '''
+        """
         Build the point object based on the measurement result
         according to report config.
-        '''
+        """
         # get test level data
         self.test_name = mmr.result.iteration.test.name
         self.test_config = report_config['tests'][self.test_name]
@@ -90,9 +90,9 @@ def __init__(self, mmr, common_args, report_config):
         }
 
     def sort_arg_vals(self):
-        '''
+        """
         Sort object argument values according to the configuration.
-        '''
+        """
         records_order = self.test_config['records_order']
         if self.test_config['records_order']:
             args_vals_sorted = {
@@ -105,9 +105,9 @@ def sort_arg_vals(self):
 
     @staticmethod
     def by_test_name_sort(by_test_name_points, ordered_test_names):
-        '''
+        """
         Return groups of points by name, sorted according to the configuration.
-        '''
+        """
         by_test_name_points_sorted = {
             test_name: by_test_name_points[test_name]
             for test_name in ordered_test_names
@@ -118,9 +118,9 @@ def by_test_name_sort(by_test_name_points, ordered_test_names):
 
 
 class ReportMeasurementLevel:
-    '''
+    """
     This class describes the report blocks corresponding to the measurements.
-    '''
+    """
 
     def __init__(
         self,
@@ -140,10 +140,10 @@ def __init__(
 
 
 class ReportArgsValsLevel:
-    '''
+    """
     This class describes the report blocks corresponding to the test arguments
     and their values.
-    '''
+    """
 
     def __init__(
         self,
@@ -237,9 +237,9 @@ def __init__(
 
 
 class ReportTestLevel:
-    '''
+    """
     This class describes the report blocks corresponding to the tests.
-    '''
+    """
 
     def __init__(self, test_name, common_args, test_points, report_config):
         test_config = report_config['tests'][test_name]
diff --git a/bublik/core/report/services.py b/bublik/core/report/services.py
index a862805ae..afcb4724a 100644
--- a/bublik/core/report/services.py
+++ b/bublik/core/report/services.py
@@ -21,10 +21,10 @@
 
 
 def get_common_args(mmrs_test):
-    '''
+    """
     Collect arguments that have the same values for all iterations of the test
     with the passed name within the passed package.
-    '''
+    """
     mmrs_test_ids = mmrs_test.values_list('id', flat=True)
 
     return dict(
@@ -45,9 +45,9 @@ def get_common_args(mmrs_test):
 
 
 def filter_by_axis_y(mmrs_test, axis_y):
-    '''
+    """
     Filter passed measurement results QS by axis y value from config.
-    '''
+    """
     mmrs_test_axis_y = MeasurementResult.objects.none()
     for measurement in axis_y:
         mmrs_test_measurement = mmrs_test.all()
@@ -88,10 +88,10 @@ def filter_by_axis_y(mmrs_test, axis_y):
 
 
 def filter_by_not_show_args(mmrs_test, not_show_args):
-    '''
+    """
     Drop measurement results corresponding to iterations with the passed
     arguments values from the passed measurement results QS.
-    '''
+    """
     not_show_mmrs = MeasurementResult.objects.none()
     for arg, vals in not_show_args.items():
         arg_vals_mmrs = mmrs_test.filter(
@@ -106,7 +106,7 @@ def filter_by_not_show_args(mmrs_test, not_show_args):
 class ReportService:
     @staticmethod
     def get_report_config(config_id: int) -> tuple[Config, dict, dict]:
-        '''
+        """
         Get and validate a report configuration.
 
         Args:
@@ -117,7 +117,7 @@ def get_report_config(config_id: int) -> tuple[Config, dict, dict]:
 
         Raises:
             NotFoundError: if config not found
-        '''
+        """
         try:
             report_config_obj = Config.objects.get(id=config_id)
         except ObjectDoesNotExist as e:
@@ -138,7 +138,7 @@ def get_report_config(config_id: int) -> tuple[Config, dict, dict]:
 
     @staticmethod
     def get_configs_for_run_report(run) -> list[dict]:
-        '''
+        """
         Get available report configurations for a run.
 
         Args:
@@ -146,7 +146,7 @@ def get_configs_for_run_report(run) -> list[dict]:
 
         Returns:
             List of available report config dictionaries
-        '''
+        """
         iters = TestIterationResult.objects.filter(test_run=run)
         test_names = list(
             iters.filter(iteration__test__result_type=ResultType.conv(ResultType.TEST))
@@ -182,7 +182,7 @@ def get_configs_for_run_report(run) -> list[dict]:
 
     @staticmethod
     def get_most_recent_config_for_run_report(run) -> list[dict]:
-        '''
+        """
         Get the ID of the most recent available report configuration for a run.
 
         Args:
@@ -191,7 +191,7 @@ def get_most_recent_config_for_run_report(run) -> list[dict]:
         Returns:
             ID of the most recent report config if available,
             otherwise None if no configs exist.
-        '''
+        """
 
         run_report_configs_data = ReportService.get_configs_for_run_report(run)
         if run_report_configs_data:
@@ -201,7 +201,7 @@ def get_most_recent_config_for_run_report(run) -> list[dict]:
 
     @staticmethod
     def generate_report(run_id: int, config_id: int) -> dict:
-        '''
+        """
         Generate full report for a run using specified config.
 
         Args:
@@ -213,7 +213,7 @@ def generate_report(run_id: int, config_id: int) -> dict:
 
         Raises:
             NotFoundError: if run not found or config not found
-        '''
+        """
         warnings = []
 
         # Get run
diff --git a/bublik/core/result/services.py b/bublik/core/result/services.py
index 5df19a45d..b94d0bcd6 100644
--- a/bublik/core/result/services.py
+++ b/bublik/core/result/services.py
@@ -27,7 +27,7 @@
 class ResultService:
     @staticmethod
     def get_result(result_id: int) -> models.TestIterationResult:
-        '''
+        """
         Get a result by ID.
 
         Args:
@@ -38,7 +38,7 @@ def get_result(result_id: int) -> models.TestIterationResult:
 
         Raises:
             NotFoundError: if result not found
-        '''
+        """
         try:
             return models.TestIterationResult.objects.get(id=result_id)
         except ObjectDoesNotExist as e:
@@ -47,7 +47,7 @@ def get_result(result_id: int) -> models.TestIterationResult:
 
     @staticmethod
     def get_result_details(result_id: int) -> dict:
-        '''
+        """
         Get full details for a single result.
 
         Args:
@@ -55,7 +55,7 @@ def get_result_details(result_id: int) -> dict:
 
         Returns:
             Dictionary with full result details
-        '''
+        """
 
         result = ResultService.get_result(result_id)
 
@@ -63,7 +63,7 @@ def get_result_details(result_id: int) -> dict:
 
     @staticmethod
     def get_result_measurements(result_id: int) -> dict:
-        '''
+        """
         Get measurements for a result.
 
         Args:
@@ -71,7 +71,7 @@ def get_result_measurements(result_id: int) -> dict:
 
         Returns:
             Dictionary with run_id, iteration_id, charts, and tables
-        '''
+        """
         result = ResultService.get_result(result_id)
 
         # Get tables
@@ -87,7 +87,7 @@ def get_result_measurements(result_id: int) -> dict:
 
     @staticmethod
     def get_result_artifacts_and_verdicts(result_id: int) -> dict:
-        '''
+        """
         Get artifacts and verdicts for a result.
 
         Args:
@@ -95,7 +95,7 @@ def get_result_artifacts_and_verdicts(result_id: int) -> dict:
 
         Returns:
             Dictionary with artifacts and verdicts lists
-        '''
+        """
         result_metas = models.Meta.objects.filter(metaresult__result__id=result_id)
         return {
             'artifacts': list(result_metas.filter(type='artifact').values()),
@@ -111,7 +111,7 @@ def list_results(
         result_properties: str | None = None,
         requirements: str | None = None,
     ):
-        '''
+        """
         List results with filtering.
 
         Args:
@@ -129,7 +129,7 @@ def list_results(
 
         Raises:
             ValidationError: if validation fails
-        '''
+        """
         queries = Q()
         queryset = models.TestIterationResult.objects.filter()
         query_delimiter = settings.QUERY_DELIMITER
@@ -236,7 +236,7 @@ def list_results_paginated(
         page: int | None = None,
         page_size: int | None = None,
     ) -> dict:
-        '''
+        """
         List results with filtering and pagination.
 
         Args:
@@ -253,7 +253,7 @@ def list_results_paginated(
 
         Returns:
             Dictionary with pagination metadata and result details
-        '''
+        """
         queryset = ResultService.list_results(
             parent_id=parent_id,
             test_name=test_name,
diff --git a/bublik/core/routers.py b/bublik/core/routers.py
index 9b97e0dad..f5f6af77e 100644
--- a/bublik/core/routers.py
+++ b/bublik/core/routers.py
@@ -5,13 +5,13 @@
 
 
 class ActionsOnlyRouter(DefaultRouter):
-    '''
+    """
     A router for APIs providing only custom endpoints which are generated
     by @action() on the viewset.
 
     Forbids default methods such as:
     list, retrieve, create, update, partial_update, and destroy
     disabling root view generation.
-    '''
+    """
 
     include_root_view = False
diff --git a/bublik/core/run/compromised.py b/bublik/core/run/compromised.py
index 958d71abc..d879eb89a 100644
--- a/bublik/core/run/compromised.py
+++ b/bublik/core/run/compromised.py
@@ -43,7 +43,7 @@ def get_compromised_details(run):
 
 def validate_compromised_request(run_id, comment, bug, reference):
     if not run_id:
-        return 'Run id couldn\'t be None.'
+        return "Run id couldn't be None."
 
     if not comment:
         return 'To mark runs as compromised comment is required.'
diff --git a/bublik/core/run/external_links.py b/bublik/core/run/external_links.py
index b0d8bac3c..521aa4a9a 100644
--- a/bublik/core/run/external_links.py
+++ b/bublik/core/run/external_links.py
@@ -65,12 +65,12 @@ def get_sources(result, source=None):
 
 
 def get_result_log(result):
-    '''
+    """
     Returns result source link to log.
 
     Param @result can be either TestIterationResult object or ID
     of a run itself or any test result.
-    '''
+    """
 
     try:
         run_source_link = get_sources(result)
@@ -94,9 +94,9 @@ def get_result_log(result):
 
 
 def get_trc_brief(result):
-    '''
+    """
     Returns result source link to trc-brief.
-    '''
+    """
 
     try:
         run_source_link = get_sources(result)
diff --git a/bublik/core/run/fields.py b/bublik/core/run/fields.py
index a0555a82d..aed93b9ed 100644
--- a/bublik/core/run/fields.py
+++ b/bublik/core/run/fields.py
@@ -25,7 +25,7 @@ def __init__(self, *, strip=True, empty_value='', **kwargs):
         self.validators.append(ProhibitNullCharactersValidator())
 
     def to_python(self, value):
-        '''Return a string.'''
+        """Return a string."""
         if value not in self.empty_values:
             try:
                 return get_test_by_full_path(value)
diff --git a/bublik/core/run/filter_expression.py b/bublik/core/run/filter_expression.py
index 4a7367312..f6e380bd3 100644
--- a/bublik/core/run/filter_expression.py
+++ b/bublik/core/run/filter_expression.py
@@ -89,7 +89,7 @@ def filter_value(val, op, negation):
                 op = op_correspondings.get(op, {}).get('negation', op)
 
             if op not in op_correspondings:
-                msg = f'Unknown relation value: \'{op}\'. Expected: = / != / < / <= / > / >='
+                msg = f"Unknown relation value: '{op}'. Expected: = / != / < / <= / > / >="
                 raise ValueError(msg)
 
             if expr_type == 'test_argument':
@@ -168,7 +168,7 @@ def metas_append(self, meta):
     def get_meta_by_alias(self, alias):
         meta = self.metasd.get(alias)
         if not meta:
-            msg = f'Failed to get meta by alias \'{alias}\''
+            msg = f"Failed to get meta by alias '{alias}'"
             raise ValueError(msg)
         return meta
 
@@ -243,8 +243,7 @@ def create_meta(s, loc, toks):
             else:
                 expected = 'meta_name1 & meta_name2=32'
             msg = (
-                f'Faied to parse expression string \'{expr_str}\'. '
-                f'Expected example: {expected}',
+                f"Faied to parse expression string '{expr_str}'. Expected example: {expected}",
             )
             raise pp.ParseException(msg) from pe
 
@@ -280,9 +279,9 @@ def filter_meta(qs, var):
 
 
 def filter_by_expression(filtered_qs, expr_str, expr_type=None):
-    '''
+    """
     Filter passed QuerySet objects according to the passed expressions of the specified type.
-    '''
+    """
 
     if expr_type is None:
         expr_type = 'tag'
diff --git a/bublik/core/run/metadata.py b/bublik/core/run/metadata.py
index e73d6709e..3d47e8257 100644
--- a/bublik/core/run/metadata.py
+++ b/bublik/core/run/metadata.py
@@ -28,7 +28,7 @@
 
 
 class MetaData:
-    '''
+    """
     This class responsibilities are bellow.
     1. Check:
         - metadata version,
@@ -39,7 +39,7 @@ class MetaData:
     3. Control timezone of datetime objects.
     4. Save necessary data to create a TestIterationResult minimal instance.
     5. Get or create / force update run metas.
-    '''
+    """
 
     FMT_META_DATA_GENERATE = '{path_meta_data_script} --path {process_dir} --project {project}'
 
@@ -171,7 +171,7 @@ def __check_metadata(self, meta_data):
         if key_metas_names:
             msg = (
                 "can't identify the run, the following RUN_KEY_METAS are "
-                f"absent in metadata: {','.join(key_metas_names)}"
+                f'absent in metadata: {",".join(key_metas_names)}'
             )
             raise ImportrunsError(message=msg)
 
@@ -251,7 +251,7 @@ def get_or_create_metas(self, run):
 
             if not name and not value:
                 logger.warning(
-                    f'meta with empty \'name\' and \'value\' can\'t be saved: {m_data}',
+                    f"meta with empty 'name' and 'value' can't be saved: {m_data}",
                 )
                 continue
 
@@ -324,7 +324,7 @@ def force_update_metas(self, run):
         )
 
         logger.info(
-            f"deleted meta results: {list(deleted.values_list('meta__name', 'meta__value'))}",
+            f'deleted meta results: {list(deleted.values_list("meta__name", "meta__value"))}',
         )
 
         deleted.delete()
diff --git a/bublik/core/run/services.py b/bublik/core/run/services.py
index e0bb1e75d..0bd7d3e87 100644
--- a/bublik/core/run/services.py
+++ b/bublik/core/run/services.py
@@ -37,9 +37,9 @@
 
 
 class RunsChartGroupBy(str, Enum):
-    '''
+    """
     Supported periods for grouping runs chart data.
-    '''
+    """
 
     DAY = 'day'
     WEEK = 'week'
@@ -52,7 +52,7 @@ def values(cls) -> tuple[str, ...]:
 class RunService:
     @staticmethod
     def get_run(run_id: int) -> models.TestIterationResult:
-        '''
+        """
         Get a run by ID.
 
         Args:
@@ -63,7 +63,7 @@ def get_run(run_id: int) -> models.TestIterationResult:
 
         Raises:
             NotFoundError: if run not found
-        '''
+        """
         try:
             return models.TestIterationResult.objects.get(id=run_id)
         except ObjectDoesNotExist as e:
@@ -72,7 +72,7 @@ def get_run(run_id: int) -> models.TestIterationResult:
 
     @staticmethod
     def get_run_details(run_id: int) -> dict:
-        '''
+        """
         Get full details for a single run.
 
         Args:
@@ -80,13 +80,13 @@ def get_run_details(run_id: int) -> dict:
 
         Returns:
             Dictionary with full run details
-        '''
+        """
         run = RunService.get_run(run_id)
         return generate_all_run_details(run)
 
     @staticmethod
     def get_run_status(run_id: int) -> str:
-        '''
+        """
         Get status string for a run.
 
         Args:
@@ -94,13 +94,13 @@ def get_run_status(run_id: int) -> str:
 
         Returns:
             Status string for the run
-        '''
+        """
         run = RunService.get_run(run_id)
         return get_run_status(run)
 
     @staticmethod
     def get_run_stats(run_id: int, requirements: str | None = None) -> dict:
-        '''
+        """
         Get statistics for a run.
 
         Args:
@@ -109,12 +109,12 @@ def get_run_stats(run_id: int, requirements: str | None = None) -> dict:
 
         Returns:
             Dictionary with run statistics
-        '''
+        """
         return get_run_stats_detailed_with_comments(run_id, requirements)
 
     @staticmethod
     def get_run_source(run_id: int) -> str:
-        '''
+        """
         Get source URL for a run.
 
         Args:
@@ -122,13 +122,13 @@ def get_run_source(run_id: int) -> str:
 
         Returns:
             Source URL string
-        '''
+        """
         run = RunService.get_run(run_id)
         return get_sources(run)
 
     @staticmethod
     def get_run_compromised(run_id: int) -> dict:
-        '''
+        """
         Get compromised status for a run.
 
         Args:
@@ -136,7 +136,7 @@ def get_run_compromised(run_id: int) -> dict:
 
         Returns:
             Dictionary with compromised status data
-        '''
+        """
         run = RunService.get_run(run_id)
         compromised_data = is_run_compromised(run)
         if not compromised_data:
@@ -150,7 +150,7 @@ def mark_run_compromised(
         bug_id: str | None = None,
         reference_key: str | None = None,
     ) -> dict:
-        '''
+        """
         Mark a run as compromised.
 
         Args:
@@ -164,7 +164,7 @@ def mark_run_compromised(
 
         Raises:
             ValidationError: if validation fails
-        '''
+        """
         err_msg = validate_compromised_request(run_id, comment, bug_id, reference_key)
         if err_msg:
             raise ValidationError(err_msg)
@@ -177,12 +177,12 @@ def mark_run_compromised(
 
     @staticmethod
     def unmark_run_compromised(run_id: int) -> None:
-        '''
+        """
         Remove compromised status from a run.
 
         Args:
             run_id: The ID of the test run
-        '''
+        """
         unmark_run_compromised(run_id)
 
     @staticmethod
@@ -197,7 +197,7 @@ def list_runs_queryset(  # noqa: PLR0913
         revision_expr: str | None = None,
         branch_expr: str | None = None,
     ):
-        '''
+        """
         Get filtered runs queryset.
 
         Args:
@@ -213,7 +213,7 @@ def list_runs_queryset(  # noqa: PLR0913
 
         Returns:
             QuerySet of filtered TestIterationResult objects
-        '''
+        """
 
         queryset = models.TestIterationResult.objects.filter(test_run__isnull=True)
 
@@ -261,7 +261,7 @@ def list_runs(
         page: int | None = None,
         page_size: int | None = None,
     ) -> dict:
-        '''
+        """
         List runs filtered by date range and optionally by project.
 
         Args:
@@ -273,7 +273,7 @@ def list_runs(
 
         Returns:
             Dictionary with pagination metadata and run detail dictionaries
-        '''
+        """
 
         runs = RunService.list_runs_queryset(
             start_date=start_date,
@@ -288,7 +288,7 @@ def aggregate_runs_by_period(
         queryset,
         group_by: RunsChartGroupBy = RunsChartGroupBy.DAY,
     ) -> dict:
-        '''
+        """
         Build aggregated chart data for runs.
 
         Args:
@@ -298,7 +298,7 @@ def aggregate_runs_by_period(
         Returns:
             Dictionary with chart buckets. Each bucket contains bucket date,
             test counters, passrate and run IDs grouped by conclusion.
-        '''
+        """
 
         runs = list(queryset.values('id', 'start', 'project_id'))
 
@@ -478,12 +478,12 @@ def make_empty_run_ids_by_status():
 
     @staticmethod
     def list_runs_by_dashboard_date_queryset(date: str, project_id: int | None = None):
-        '''
+        """
         Get runs for a dashboard date using the same date source as dashboard data.
 
         Some installations configure dashboard dates through run metadata instead of
         the run start timestamp.
-        '''
+        """
         date_meta = ConfigServices.getattr_from_global(
             models.GlobalConfigs.PER_CONF.name,
             'DASHBOARD_DATE',
@@ -509,7 +509,7 @@ def list_runs_by_dashboard_date_queryset(date: str, project_id: int | None = Non
 
     @staticmethod
     def get_run_requirements(run_id: int) -> list[str]:
-        '''
+        """
         Get requirements for a run.
 
         Args:
@@ -517,7 +517,7 @@ def get_run_requirements(run_id: int) -> list[str]:
 
         Returns:
             Sorted list of requirement strings
-        '''
+        """
         run = RunService.get_run(run_id)
         return sorted(
             models.Meta.objects.filter(type='requirement', metaresult__result__test_run=run)
@@ -527,7 +527,7 @@ def get_run_requirements(run_id: int) -> list[str]:
 
     @staticmethod
     def get_nok_distribution(run_id: int) -> dict:
-        '''
+        """
         Get NOK (failure) distribution for a run.
 
         Args:
@@ -535,13 +535,13 @@ def get_nok_distribution(run_id: int) -> dict:
 
         Returns:
             Dictionary with NOK distribution data
-        '''
+        """
         run = RunService.get_run(run_id)
         return get_nok_results_distribution(run)
 
     @staticmethod
     def get_run_comment(run_id: int) -> str | None:
-        '''
+        """
         Get comment for a run.
 
         Args:
@@ -552,7 +552,7 @@ def get_run_comment(run_id: int) -> str | None:
 
         Raises:
             ValidationError: if multiple comments found
-        '''
+        """
         run = RunService.get_run(run_id)
         comments = models.MetaResult.objects.filter(meta__type='comment', result=run)
 
@@ -567,7 +567,7 @@ def get_run_comment(run_id: int) -> str | None:
 
     @staticmethod
     def create_run_comment(run_id: int, content: str) -> dict:
-        '''
+        """
         Create or update run comment.
 
         Args:
@@ -576,7 +576,7 @@ def create_run_comment(run_id: int, content: str) -> dict:
 
         Returns:
             Dictionary with comment details
-        '''
+        """
         run = RunService.get_run(run_id)
 
         with transaction.atomic():
@@ -601,7 +601,7 @@ def create_run_comment(run_id: int, content: str) -> dict:
 
     @staticmethod
     def delete_run_comment(run_id: int) -> None:
-        '''
+        """
         Delete run comment.
 
         Args:
@@ -609,7 +609,7 @@ def delete_run_comment(run_id: int) -> None:
 
         Raises:
             ValidationError: if no comment exists
-        '''
+        """
         run = RunService.get_run(run_id)
         comments = models.MetaResult.objects.filter(meta__type='comment', result=run)
 
diff --git a/bublik/core/run/stats.py b/bublik/core/run/stats.py
index 21a762764..c1968d7eb 100644
--- a/bublik/core/run/stats.py
+++ b/bublik/core/run/stats.py
@@ -209,7 +209,7 @@ def get_run_stats_detailed_with_comments(run_id, requirements):
 
 
 def add_comments(node, tests_comments):
-    '''
+    """
     Add a list of comments to each node. The comment format is
     {
         'comment_id': <meta_id>,
@@ -218,7 +218,7 @@ def add_comments(node, tests_comments):
         'comment': <meta_value>
     }
     The order of comments is determined by the serial value.
-    '''
+    """
     if node:
         node['comments'] = tests_comments.get(node['test_id'], [])
         node['comments'] = [
@@ -288,7 +288,7 @@ def get_run_stats_detailed(run_id, requirements=None):
 
 
 def get_tests_comments(run_id):
-    '''
+    """
     Return all run test comments in the format
     {
         'test_id': [
@@ -299,7 +299,7 @@ def get_tests_comments(run_id):
             }, ...
         ], ...
     }
-    '''
+    """
     test_ids = list(
         (
             TestIterationResult.objects.filter(test_run=run_id)
@@ -347,10 +347,10 @@ def get_test_runs(
     order_by='-start',
     escape_compromised=True,
 ):
-    '''
+    """
     Get test runs filtered by date and tags with possibility to exclude runs
     which contain `exclude_label` in meta labels.
-    '''
+    """
 
     runs = TestIterationResult.objects.filter(test_run=None)
     if escape_compromised:
diff --git a/bublik/core/server/services.py b/bublik/core/server/services.py
index c5e007539..1b51767b4 100644
--- a/bublik/core/server/services.py
+++ b/bublik/core/server/services.py
@@ -7,13 +7,12 @@
 
 
 class ServerService:
-
     @staticmethod
     def get_version() -> dict:
-        '''
+        """
         Get server version information.
 
         Returns:
             Dictionary with repository revision information
-        '''
+        """
         return settings.REPO_REVISIONS
diff --git a/bublik/core/shortcuts.py b/bublik/core/shortcuts.py
index 5bb9aedf6..e4fbc53d1 100644
--- a/bublik/core/shortcuts.py
+++ b/bublik/core/shortcuts.py
@@ -14,10 +14,10 @@ def get_current_scheme_host_prefix(request):
 
 
 def build_absolute_uri(request, endpoint):
-    '''
+    """
     This is a wrapper for basic request.build_absolute_uri()
     that respects URL_PREFIX.
-    '''
+    """
     return urljoin(get_current_scheme_host_prefix(request), endpoint.lstrip('/'))
 
 
diff --git a/bublik/core/testing_coverage.py b/bublik/core/testing_coverage.py
index ffbeab66b..4faf9e36b 100644
--- a/bublik/core/testing_coverage.py
+++ b/bublik/core/testing_coverage.py
@@ -61,11 +61,11 @@ def __repr__(self):
 
 
 class TestingCoverage:
-    '''
+    """
     The object contains data of testing coverage structured in dependence on
     specified tags which are considered to be significant. It can be used to
     generate pdf or html reports.
-    '''
+    """
 
     def __init__(
         self,
@@ -182,7 +182,6 @@ def put_table_tail(repf):
 
         def generate_tables(packages, package_stats):
             with open(self.path_report_content, 'w') as repf:
-
                 repf.write(
                     f'\\lfoot{{Report for the period from {datetime.date(self.start_date)} to '
                     f'{datetime.date(self.finish_date)}}}\n\n',
@@ -257,7 +256,7 @@ def generate_tables(packages, package_stats):
         for i, package in enumerate(packages):
             if not package_stats[package] or package_stats[package] == 0:
                 for p in packages:
-                    if p.startswith(packages[i] + '/'):
+                    if p.startswith(packages[i] + '/'):  # noqa: PLR1736
                         packages.remove(package)
 
         generate_tables(packages, package_stats)
diff --git a/bublik/core/tree/representation.py b/bublik/core/tree/representation.py
index 952c215b8..c04db92fc 100644
--- a/bublik/core/tree/representation.py
+++ b/bublik/core/tree/representation.py
@@ -11,13 +11,13 @@
 
 
 class Tree(TreeLib):
-    '''The class for tree representation in different formats.'''
+    """The class for tree representation in different formats."""
 
     def to_linear_dict(self, with_data=False):
-        '''
+        """
         Exports the tree in the linear format representing node children
         as an adjacency list.
-        '''
+        """
         adjacency_list = defaultdict(dict)
         if self.nodes:
             for n in self.expand_tree(mode=self.WIDTH):
diff --git a/bublik/core/tree/services.py b/bublik/core/tree/services.py
index 88fc7b6d3..a560cce99 100644
--- a/bublik/core/tree/services.py
+++ b/bublik/core/tree/services.py
@@ -11,7 +11,7 @@
 class TreeService:
     @staticmethod
     def get_tree(run_id: int) -> dict:
-        '''
+        """
         Get tree representation of a run.
 
         Args:
@@ -22,7 +22,7 @@ def get_tree(run_id: int) -> dict:
 
         Raises:
             NotFoundError: if run not found
-        '''
+        """
         result = ResultService.get_result(run_id)
 
         # Try to get cached tree
@@ -51,7 +51,7 @@ def get_tree(run_id: int) -> dict:
 
     @staticmethod
     def get_tree_path(result_id: int) -> list[int]:
-        '''
+        """
         Get path from root to a specific node.
 
         Args:
@@ -62,6 +62,6 @@ def get_tree_path(result_id: int) -> list[int]:
 
         Raises:
             NotFoundError: if result not found
-        '''
+        """
         result = ResultService.get_result(result_id)
         return path_to_node(result)
diff --git a/bublik/core/utils.py b/bublik/core/utils.py
index 1cbcf81fa..817c257dc 100644
--- a/bublik/core/utils.py
+++ b/bublik/core/utils.py
@@ -46,19 +46,19 @@ def key_value_list_transforming(items, delim=settings.KEY_VALUE_DELIMITER):
     for item in items:
         if isinstance(item, dict):
             if all(k in item for k in ('name', 'value')):
-                '''Example: item = { 'name': n, 'value': v }.'''
+                """Example: item = { 'name': n, 'value': v }."""
                 key = item.get('name')
                 value = item.get('value')
             elif 'value' in item:
-                '''Example: item = { 'value': v }.'''
+                """Example: item = { 'value': v }."""
                 key = item.get('value')
                 value = None
             else:
-                '''Example: item = { n: v }.'''
+                """Example: item = { n: v }."""
                 key, value = item.popitem()
 
         elif isinstance(item, tuple):
-            '''Example: item = ( n, v ).'''
+            """Example: item = ( n, v )."""
             key, value = item
 
         else:
@@ -113,10 +113,10 @@ def search_files_in_sub_dirs(basedir, filename):
 
 
 def get_local_log(filename, basedir=settings.MANAGEMENT_COMMANDS_LOG):
-    '''
+    """
     Returns absolute path to the log or raises RunTimeError if
     no one or more than one log file was found.
-    '''
+    """
 
     files = list(search_files_in_sub_dirs(basedir, filename))
 
@@ -205,7 +205,6 @@ def get_same_key_values(test_list, extra_condition=None):
 
     # iterating each dictionary for similar key's value
     for key in keys:
-
         # using all to check all keys with similar values
         flag = all(test_list[0][key] == ele[key] for ele in test_list)
 
diff --git a/bublik/data/managers/result.py b/bublik/data/managers/result.py
index 6ef96b3c1..af07fa1d3 100644
--- a/bublik/data/managers/result.py
+++ b/bublik/data/managers/result.py
@@ -11,7 +11,7 @@
 from bublik.data.models.meta import Meta
 
 
-'''
+"""
 A custom QuerySet allows to do:
 
 >>> test_self = TestIterationResult.objects.filter(test_run=1)
@@ -23,7 +23,7 @@
 [1] https://docs.djangoproject.com/en/dev/topics/db/managers/#custom-managers
 [2] https://docs.djangoproject.com/en/dev/topics/db/managers/#calling-custom-queryset-methods-from-the-manager
 [3] https://docs.djangoproject.com/en/dev/topics/db/managers/#creating-a-manager-with-queryset-methods
-'''
+"""
 
 
 class TestIterationResultQuerySet(QuerySet):
@@ -87,11 +87,11 @@ def filter_by_run_metas(self, metas, meta_types=None):
         return self
 
     def filter_runs_by_date(self, from_d: datetime, to_d: datetime) -> QuerySet:
-        '''
+        """
         This method returns a TestIterationResultsQuerySet which contains
         TestIterationResults which were executed during the specified
         period of time.
-        '''
+        """
 
         return self.filter(start__gte=from_d, start__lte=to_d)
 
diff --git a/bublik/data/models/__init__.py b/bublik/data/models/__init__.py
index fcb696f9c..29547fb2b 100644
--- a/bublik/data/models/__init__.py
+++ b/bublik/data/models/__init__.py
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (C) 2016-2023 OKTET Labs Ltd. All rights reserved.
-'''
+"""
 The database is destined to keep mass automatic testing results.
 In general it is designed to be flexible and keep tests structured in various
 ways. Tests results can have links to different kinds of external or
@@ -19,7 +19,7 @@
 
 The database is capable to keep thousands of test runs which contain thousands
 of test iteration results.
-'''
+"""
 
 from .config import Config, ConfigTypes, GlobalConfigs
 from .endpoint_url import EndpointURL
diff --git a/bublik/data/models/config.py b/bublik/data/models/config.py
index d690fb243..dbc936645 100644
--- a/bublik/data/models/config.py
+++ b/bublik/data/models/config.py
@@ -18,9 +18,9 @@
 
 
 class ConfigTypes(models.TextChoices):
-    '''
+    """
     All available configuration types.
-    '''
+    """
 
     GLOBAL = 'global'
     REPORT = 'report'
@@ -32,9 +32,9 @@ def all(cls):
 
 
 class GlobalConfigs(Enum):
-    '''
+    """
     All available global configuration names and descriptions.
-    '''
+    """
 
     PER_CONF = ('per_conf', 'The main project configuration')
     REFERENCES = ('references', 'Project references')
@@ -131,9 +131,9 @@ def get_global(self, config_name, project_id=...):
 
 
 class Config(models.Model):
-    '''
+    """
     Configurations.
-    '''
+    """
 
     created = models.DateTimeField(
         auto_now_add=True,
diff --git a/bublik/data/models/endpoint_url.py b/bublik/data/models/endpoint_url.py
index 5d233e5cd..18f5132ef 100644
--- a/bublik/data/models/endpoint_url.py
+++ b/bublik/data/models/endpoint_url.py
@@ -11,9 +11,9 @@
 
 
 class EndpointURL(models.Model):
-    '''
+    """
     The endpoints of Bublik URLs and the corresponding hashes used for short URLs.
-    '''
+    """
 
     hashable = (
         'view',
diff --git a/bublik/data/models/eventlog.py b/bublik/data/models/eventlog.py
index 83f3c7d27..5e5b84f08 100644
--- a/bublik/data/models/eventlog.py
+++ b/bublik/data/models/eventlog.py
@@ -1,8 +1,8 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (C) 2016-2023 OKTET Labs Ltd. All rights reserved.
-'''
+"""
 Contains models responsible for storing data on events happening in Bublik.
-'''
+"""
 
 from django.db import models
 
@@ -11,10 +11,10 @@
 
 
 class EventLog(models.Model):
-    '''
+    """
     Stores data on events such as start and finish timestamps, facility and
     message.
-    '''
+    """
 
     class FacilityChoices(models.TextChoices):
         IMPORTRUNS = 'importruns'
diff --git a/bublik/data/models/expectation.py b/bublik/data/models/expectation.py
index c60b6e1fe..d52ff5444 100644
--- a/bublik/data/models/expectation.py
+++ b/bublik/data/models/expectation.py
@@ -15,9 +15,9 @@
 
 
 class Expectation(models.Model):
-    '''
+    """
     TRC test expectation instance.
-    '''
+    """
 
     hashable = ('expectmeta_set',)
 
@@ -43,9 +43,9 @@ def __repr__(self):
 
 
 class ExpectMeta(models.Model):
-    '''
+    """
     Expectation metas.
-    '''
+    """
 
     hashable = ('serial', 'meta', 'reference')
 
@@ -63,8 +63,8 @@ class ExpectMeta(models.Model):
     )
     serial = models.IntegerField(
         default=0,
-        help_text='''\
-Serial number of a meta result, can be used to determine verdicts order.''',
+        help_text="""\
+Serial number of a meta result, can be used to determine verdicts order.""",
     )
 
     class Admin:
diff --git a/bublik/data/models/job.py b/bublik/data/models/job.py
index 21df77490..503fd6899 100644
--- a/bublik/data/models/job.py
+++ b/bublik/data/models/job.py
@@ -16,7 +16,6 @@
 
 
 class Job(models.Model):
-
     class NameChoices(models.TextChoices):
         IMPORTRUNS = 'importruns'
         META_CATEGORIZATION = 'meta_categorization'
@@ -52,7 +51,6 @@ def __repr__(self):
 
 
 class ImportJob(Job):
-
     url = models.TextField(null=False)
 
     class Admin:
diff --git a/bublik/data/models/measurement.py b/bublik/data/models/measurement.py
index 3e89cb7b9..b25328d4c 100644
--- a/bublik/data/models/measurement.py
+++ b/bublik/data/models/measurement.py
@@ -21,10 +21,10 @@
 
 
 class ChartViewType:
-    '''
+    """
     This class stands for converting a type of measurement reference
     to the one symbol.
-    '''
+    """
 
     AXIS_X = 'axis_x'
     AXIS_Y = 'axis_y'
@@ -48,9 +48,9 @@ def choices(cls):
 
 
 class Measurement(models.Model):
-    '''
+    """
     The table to describe measurement characteristics.
-    '''
+    """
 
     hashable = ('metas',)
 
@@ -108,9 +108,9 @@ def representation(self):
 
 
 class MeasurementResult(models.Model):
-    '''
+    """
     The table to combine measurement results and its measurement characteristics.
-    '''
+    """
 
     measurement = models.ForeignKey(
         Measurement,
@@ -127,8 +127,8 @@ class MeasurementResult(models.Model):
     )
     serial = models.IntegerField(
         default=0,
-        help_text='''\
-Serial number can be used to determine results order.''',
+        help_text="""\
+Serial number can be used to determine results order.""",
     )
 
     class Meta:
@@ -150,10 +150,10 @@ def representation(self, additional='result'):
 
     @property
     def measurement_group_key(self):
-        '''
+        """
         This function returns a tuple containing key information about the measurement,
         which allows grouping the measurement results.
-        '''
+        """
         mm_repr = self.measurement.representation()
         mm_repr.pop('measurement_id')
         mm_repr.pop('comments')
@@ -169,9 +169,9 @@ def make_hashable(mm_repr):
 
 
 class MeasurementResultList(models.Model):
-    '''
+    """
     The table to store sequences of measurement results.
-    '''
+    """
 
     measurement = models.ForeignKey(
         Measurement,
@@ -211,9 +211,9 @@ def representation(self, additional='result'):
 
 
 class View(models.Model):
-    '''
+    """
     The table to describe measurement view characteristics.
-    '''
+    """
 
     hashable = ('metas',)
 
@@ -244,9 +244,9 @@ def representation(self):
 
 
 class ChartView(models.Model):
-    '''
+    """
     The table to describe views of two measurements on a single graph
-    '''
+    """
 
     view = models.ForeignKey(
         View,
diff --git a/bublik/data/models/meta.py b/bublik/data/models/meta.py
index 521ec0015..70edf29ae 100644
--- a/bublik/data/models/meta.py
+++ b/bublik/data/models/meta.py
@@ -19,18 +19,18 @@
 
 
 class Meta(models.Model):
-    '''
+    """
     Meta information to mark runs and iteration results in arbitrary way.
-    '''
+    """
 
     hashable = ('name', 'type', 'value', 'comment')
 
     name = models.CharField(max_length=64, null=True, help_text='The meta name.')
     type = models.CharField(
         max_length=64,
-        help_text='''\
+        help_text="""\
 The meta type, enumeration: result, verdict, note, error, tag, label, \
-revision, branch, repo, log, import, count, objective, comment.''',
+revision, branch, repo, log, import, count, objective, comment.""",
         db_index=True,
     )
     value = models.TextField(null=True, blank=True, help_text='The meta value or none.')
@@ -71,9 +71,9 @@ def abnormal(self):
 
 
 class MetaCategory(models.Model):
-    '''
+    """
     Meta priority/category association model
-    '''
+    """
 
     name = models.CharField(
         max_length=64,
@@ -94,9 +94,9 @@ class MetaCategory(models.Model):
     )
     type = models.CharField(
         max_length=64,
-        help_text='''\
+        help_text="""\
 The meta type, enumeration: result, verdict, note, error, tag, label, \
-revision, branch, repo, log, import, count, objective.''',
+revision, branch, repo, log, import, count, objective.""",
     )
     project = models.ForeignKey(
         Project,
@@ -120,9 +120,9 @@ def __repr__(self):
 
 
 class MetaPattern(models.Model):
-    '''
+    """
     Meta pattern
-    '''
+    """
 
     pattern = models.CharField(
         max_length=256,
diff --git a/bublik/data/models/project.py b/bublik/data/models/project.py
index 2ab45acc0..0afb4fd66 100644
--- a/bublik/data/models/project.py
+++ b/bublik/data/models/project.py
@@ -11,9 +11,9 @@
 
 
 class Project(models.Model):
-    '''
+    """
     Projects.
-    '''
+    """
 
     name = models.CharField(
         max_length=64,
diff --git a/bublik/data/models/reference.py b/bublik/data/models/reference.py
index 5e683df5f..345ed209f 100644
--- a/bublik/data/models/reference.py
+++ b/bublik/data/models/reference.py
@@ -10,18 +10,18 @@
 
 
 class Reference(models.Model):
-    '''
+    """
     Reference types.
-    '''
+    """
 
     hashable = ('name', 'uri')
 
     name = models.CharField(max_length=64, help_text='The reference type name.')
     uri = models.TextField(
         max_length=128,
-        help_text='''\
+        help_text="""\
 The reference prefix or URI, e.g. https://site.com/path/to/logs,
-https://bugzilla.somebody.com/).''',
+https://bugzilla.somebody.com/).""",
     )
 
     class Meta:
diff --git a/bublik/data/models/result.py b/bublik/data/models/result.py
index cff7637aa..32da4930f 100644
--- a/bublik/data/models/result.py
+++ b/bublik/data/models/result.py
@@ -34,9 +34,9 @@
 
 
 class RunStatus:
-    '''
+    """
     This is an interface to describe all run statuses.
-    '''
+    """
 
     DONE = 'DONE'
     RUNNING = 'RUNNING'
@@ -52,9 +52,9 @@ def all(cls):
 
 
 class RunStatusByUnexpected:
-    '''
+    """
     This is an interface to describe all run statuses depending on unexpected rate.
-    '''
+    """
 
     SUCCESS = 'success'
     WARNING = 'warning'
@@ -83,9 +83,9 @@ def identify(cls, run_stats, project_id):
 
 
 class RunConclusion:
-    '''
+    """
     This is an interface to describe all run conclusions.
-    '''
+    """
 
     OK = 'run-ok'
     RUNNING = 'run-running'
@@ -155,11 +155,11 @@ def identify(
 
 
 class ResultStatus:
-    '''
+    """
     This is an interface gathering different result statuses to the fixed group.
     Such a system is useful to have one interface for all projects allowing them
     have any result statuses they want just assigning them to the fixed group.
-    '''
+    """
 
     RESULT_STATUSES_BY_GROUPS: ClassVar[dict] = {
         'passed': ['PASSED'],
@@ -203,9 +203,9 @@ def discover_statuses(groups):
 
 
 class ResultType:
-    '''
+    """
     This class stands for converting a type of result to the one symbol.
-    '''
+    """
 
     TEST = 'test'
     SESSION = 'session'
@@ -233,9 +233,9 @@ def choices(cls):
 
 
 class Test(models.Model):
-    '''
+    """
     The table contains test names and relations to other tests.
-    '''
+    """
 
     name = models.CharField(max_length=64, help_text='The test name')
 
@@ -243,10 +243,10 @@ class Test(models.Model):
         'self',
         on_delete=models.CASCADE,
         null=True,
-        help_text='''\
+        help_text="""\
     A parent test (package) identifier - can be used to reassemble the test path.
     Note! This path does not include the test and package arguments, it represents
-    only packages path like 'package1/package2/package3/test'.''',
+    only packages path like 'package1/package2/package3/test'.""",
     )
 
     result_type = models.CharField(
@@ -271,9 +271,9 @@ def get_descendants(self):
 
 
 class TestArgument(models.Model):
-    '''
+    """
     Test parameters with possible values.
-    '''
+    """
 
     hashable = ('name', 'value')
 
@@ -292,9 +292,9 @@ def __repr__(self):
 
 
 class TestIteration(models.Model):
-    '''
+    """
     A test with a determined set of argument values.
-    '''
+    """
 
     test = models.ForeignKey(Test, on_delete=models.CASCADE, help_text='The test identifier.')
 
@@ -318,12 +318,12 @@ def __repr__(self):
         )
 
     def get_packages(self, package_strip=None, package_ignore=None):
-        '''
+        """
         Get list of all packages from the database ignoring packages listed in
         package_ignore. Packages are returned in string representation
         including path, substring package_strip is dropped form a package
         pathname.
-        '''
+        """
         packages = []
         iterations = TestIteration.objects.filter(hash__isnull=True)
         for iteration in iterations:
@@ -355,13 +355,13 @@ def get_packages(self, package_strip=None, package_ignore=None):
 
 
 class TestIterationRelation(models.Model):
-    '''
+    """
     The table serves to connect all related test iterations. A test package
     can have test arguments and it is considered to be a test iteration. The
     table is excessive and keeps all parents for each test iteration. In the
     result all parents of a test iteration can be extracted by one request
     to the database.
-    '''
+    """
 
     test_iteration = models.ForeignKey(
         TestIteration,
@@ -394,12 +394,12 @@ def __repr__(self):
 
 
 class TestIterationResult(models.Model):
-    '''
+    """
     Result of a test iteration execution. Note! a test run (sequence of test
     iteration results) is considered to be another one TestIterationResult
     object. All test iteration results which belong to a test run refer to
     this test run using field test_run.
-    '''
+    """
 
     iteration = models.ForeignKey(
         TestIteration,
@@ -425,27 +425,27 @@ class TestIterationResult(models.Model):
 
     tin = models.IntegerField(
         null=True,
-        help_text='''\
-The test iteration identifier (TIN) which is generated during the testing.''',
+        help_text="""\
+The test iteration identifier (TIN) which is generated during the testing.""",
     )
 
     exec_seqno = models.IntegerField(
         db_index=True,
         null=True,
-        help_text='''\
-The execution sequence number (the actual test ID) which is generated during the testing.''',
+        help_text="""\
+The execution sequence number (the actual test ID) which is generated during the testing.""",
     )
 
     start = models.DateTimeField(
         db_index=True,
-        help_text='''\
-Timestamp of the iteration (or test run) execution start.''',
+        help_text="""\
+Timestamp of the iteration (or test run) execution start.""",
     )
 
     finish = models.DateTimeField(
         null=True,
-        help_text='''\
-Timestamp of the iteration (or test run) execution end.''',
+        help_text="""\
+Timestamp of the iteration (or test run) execution end.""",
     )
 
     project = models.ForeignKey(
@@ -471,21 +471,21 @@ def __repr__(self):
 
     @cached_property
     def root(self):
-        '''
+        """
         Get root test iteration result from any test iteration result.
         Necessary while test_run of root is None: bug 11428.
-        '''
+        """
         if not self.test_run:
             return self
         return self.test_run
 
     @cached_property
     def main_package(self):
-        '''
+        """
         Get main package of the run from any test iteration result.
         For root test iteration result and main package itself the actual
         main package is returned.
-        '''
+        """
         return (
             TestIterationResult.objects.filter(test_run=self.root, parent_package__isnull=True)
             .order_by('start')
@@ -501,9 +501,9 @@ def duration(self):
 
     @cached_property
     def import_mode(self):
-        '''
+        """
         Get import mode of the run from any test iteration result.
-        '''
+        """
         meta_result = get_or_none(
             MetaResult.objects,
             result=self.root,
@@ -523,9 +523,9 @@ def branches(self):
 
 
 class MetaResult(models.Model):
-    '''
+    """
     The table connects a test iteration results with metadata and references.
-    '''
+    """
 
     meta = models.ForeignKey(Meta, on_delete=models.CASCADE, help_text='A metadata identifier.')
     reference = models.ForeignKey(
@@ -536,13 +536,13 @@ class MetaResult(models.Model):
     )
     ref_index = models.IntegerField(
         null=True,
-        help_text='''\
-A reference index, can be used for example to specify a line in the log.''',
+        help_text="""\
+A reference index, can be used for example to specify a line in the log.""",
     )
     serial = models.IntegerField(
         default=0,
-        help_text='''\
-Serial number of a meta result, can be used to determine verdicts order.''',
+        help_text="""\
+Serial number of a meta result, can be used to determine verdicts order.""",
     )
     result = models.ForeignKey(
         TestIterationResult,
@@ -565,9 +565,9 @@ def __repr__(self):
 
 
 class MetaTest(models.Model):
-    '''
+    """
     The table connects a test with metadata.
-    '''
+    """
 
     updated = models.DateTimeField(
         auto_now_add=True,
diff --git a/bublik/data/models/user.py b/bublik/data/models/user.py
index b48379a5f..07fb6e0b2 100644
--- a/bublik/data/models/user.py
+++ b/bublik/data/models/user.py
@@ -1,8 +1,9 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (C) 2016-2023 OKTET Labs Ltd. All rights reserved.
-'''
+"""
 Contains models responsible for saving user data
-'''
+"""
+
 import typing
 
 from django.contrib.auth.base_user import BaseUserManager
@@ -15,15 +16,15 @@
 
 
 class UserManager(BaseUserManager):
-    '''
+    """
     Custom user model manager where email is the unique identifiers
     for authentication instead of usernames.
-    '''
+    """
 
     def create_user(self, email, password, **extra_fields):
-        '''
+        """
         Create and save a user with the given email and password.
-        '''
+        """
         if not email:
             msg = 'The email must be set'
             raise ValueError(msg)
@@ -33,9 +34,9 @@ def create_user(self, email, password, **extra_fields):
         return user
 
     def create_superuser(self, email, password, **extra_fields):
-        '''
+        """
         Create and save an admin user with the given email and password.
-        '''
+        """
         extra_fields.setdefault('is_active', True)
         extra_fields.setdefault('roles', UserRoles.ADMIN)
 
@@ -48,9 +49,9 @@ def create_superuser(self, email, password, **extra_fields):
         return self.create_user(email, password, **extra_fields)
 
     def create_system_user(self):
-        '''
+        """
         Create and save the system user.
-        '''
+        """
         system_user = self.model(is_system=True)
         system_user.save()
         return system_user
diff --git a/bublik/data/serializers/auth.py b/bublik/data/serializers/auth.py
index d47b9af0b..fc67063f2 100644
--- a/bublik/data/serializers/auth.py
+++ b/bublik/data/serializers/auth.py
@@ -46,7 +46,7 @@ class Meta:
 
     def validate(self, attrs):
         if attrs['password'] != attrs['password_confirm']:
-            raise serializers.ValidationError({'password': 'Password fields don\'t match'})
+            raise serializers.ValidationError({'password': "Password fields don't match"})
 
         return attrs
 
@@ -119,7 +119,7 @@ def validate_passwords(self, passwords):
         self.is_valid(raise_exception=True)
         # Check if the new password fields match
         if passwords['new_password'] != passwords['new_password_confirm']:
-            raise serializers.ValidationError({'new_password': 'Password fields don\'t match'})
+            raise serializers.ValidationError({'new_password': "Password fields don't match"})
 
     def current_password_check(self, user, current_password):
         # Check if the passed current password is valid for the passed user
diff --git a/bublik/data/serializers/config.py b/bublik/data/serializers/config.py
index 41f188a7a..2a382f542 100644
--- a/bublik/data/serializers/config.py
+++ b/bublik/data/serializers/config.py
@@ -89,7 +89,7 @@ def validate_name(self, name):
                 or Project.objects.get(id=config_project).name
             )
             msg = (
-                f'{config_type.capitalize()} configuration \'{name}\' '
+                f"{config_type.capitalize()} configuration '{name}' "
                 f'already exist for {project_name}'
             )
             raise serializers.ValidationError(msg)
@@ -97,9 +97,9 @@ def validate_name(self, name):
         return name
 
     def validate_content(self, content):
-        '''
+        """
         Do the preprocessing and validate config content using the appropriate JSON schema.
-        '''
+        """
 
         def ensure_json(config_content):
             if isinstance(config_content, (dict, list)):
@@ -146,11 +146,11 @@ def ensure_json(config_content):
 
     @classmethod
     def initialize(cls, config_data):
-        '''
+        """
         Used for initializing configurations.
         Sets is_active=True, adds user to the provided config data and
         calls create().
-        '''
+        """
         config_data['is_active'] = True
         serializer = cls(data=config_data, context={'is_system_action': True})
         internal = serializer.to_internal_value(serializer.initial_data)
diff --git a/bublik/data/serializers/expectation.py b/bublik/data/serializers/expectation.py
index 88535fd6b..35247614e 100644
--- a/bublik/data/serializers/expectation.py
+++ b/bublik/data/serializers/expectation.py
@@ -20,11 +20,11 @@
 
 
 class ExpectMetaReadSerializer(ModelSerializer):
-    '''
+    """
     Allows data validation and forbids instances creation.
     Used for an expectation hash calculation.
     Default values are set only in update() and create().
-    '''
+    """
 
     meta = MetaSerializer(required=True)
     reference = ReferenceSerializer(required=False, default=None, allow_null=True)
@@ -44,7 +44,7 @@ def create(self):
 
 
 class ExpectMetaWriteSerializer(ModelSerializer):
-    '''Used to create ExpectMeta objects with related meta and reference.'''
+    """Used to create ExpectMeta objects with related meta and reference."""
 
     meta = MetaSerializer(required=True)
     reference = ReferenceSerializer(required=False, default=None, allow_null=True)
@@ -74,7 +74,7 @@ def get_or_create(self):
 
 
 class ExpectationSerializer(HashedModelSerializer):
-    '''
+    """
     Allows re-using an expectation object that points to the same metas.
     For this an expectation is hashed based on the related expect metas.
 
@@ -87,7 +87,7 @@ class ExpectationSerializer(HashedModelSerializer):
     The transaction of get_or_create() is atomic to prevent an Expectation
     instance to be created without expect metas if errors occurred
     in its getting or creating process.
-    '''
+    """
 
     expectmeta_set = ExpectMetaReadSerializer(many=True, required=True)
 
diff --git a/bublik/data/serializers/project.py b/bublik/data/serializers/project.py
index d7a0680f7..bf36b5e00 100644
--- a/bublik/data/serializers/project.py
+++ b/bublik/data/serializers/project.py
@@ -7,7 +7,6 @@
 
 
 class ProjectSerializer(ModelSerializer):
-
     class Meta:
         model = Project
         fields = (
diff --git a/bublik/data/serializers/result.py b/bublik/data/serializers/result.py
index 871595454..7fe0d23c8 100644
--- a/bublik/data/serializers/result.py
+++ b/bublik/data/serializers/result.py
@@ -142,12 +142,12 @@ def to_internal_value(self, data):
     def validate(self, attrs):
         test = attrs.get('test')
         if test is None:
-            msg = '\'test\' must be provided in serializer context'
+            msg = "'test' must be provided in serializer context"
             raise serializers.ValidationError(msg)
 
         project = attrs.get('project')
         if project is None:
-            msg = '\'project\' must be provided in serializer context'
+            msg = "'project' must be provided in serializer context"
             raise serializers.ValidationError(msg)
 
         meta_serializer = serialize(MetaSerializer, attrs['meta'])
@@ -188,7 +188,7 @@ def to_internal_value(self, data):
     def validate(self, attrs):
         run = attrs.get('result')
         if run is None:
-            msg = '\'run\' must be provided in serializer context'
+            msg = "'run' must be provided in serializer context"
             raise serializers.ValidationError(msg)
 
         if MetaResult.objects.filter(result=run, meta__type=attrs['meta']['type']).exists():
diff --git a/bublik/interfaces/api_v2/auth.py b/bublik/interfaces/api_v2/auth.py
index 2679a0050..5445b4aee 100644
--- a/bublik/interfaces/api_v2/auth.py
+++ b/bublik/interfaces/api_v2/auth.py
@@ -359,7 +359,7 @@ def create_user(self, request):
         user = serializer.create(request.data)
         send_verification_link_mail(request, user)
         return Response(
-            {'message': 'A verification link has been sent to the user\'s email address'},
+            {'message': "A verification link has been sent to the user's email address"},
         )
 
     @auth_required(as_admin=True)
diff --git a/bublik/interfaces/api_v2/comments.py b/bublik/interfaces/api_v2/comments.py
index b0e626614..469c5a36c 100644
--- a/bublik/interfaces/api_v2/comments.py
+++ b/bublik/interfaces/api_v2/comments.py
@@ -41,11 +41,11 @@ def get_object(self):
 
     @check_action_permission('manage_test_comments')
     def create(self, request, *args, **kwargs):
-        '''
+        """
         Add a comment to the Test by creating a MetaTest linking it
         to the retrieved or newly created comment-type Meta in the provided project.
         Request: POST tests/<test_id>/comments/?project=<project_id>.
-        '''
+        """
         test = Test.objects.get(pk=self.kwargs['test_id'])
         project = Project.objects.get(pk=request.query_params.get('project'))
         comment_data = {
@@ -61,12 +61,12 @@ def create(self, request, *args, **kwargs):
 
     @check_action_permission('manage_test_comments')
     def partial_update(self, request, *args, **kwargs):
-        '''
+        """
         Update a test comment by replacing the existing MetaTest linking the Test
         to the old Meta with a new MetaTest linking it to the received or newly
         created Meta with the new value in the same project.
         Request: PATCH tests/<test_id>/comments/<meta_id>/?project=<project_id>.
-        '''
+        """
         metatest = self.get_object()
         upd_test_comment_data = {
             'comment': request.data.get('comment'),
@@ -87,7 +87,7 @@ def partial_update(self, request, *args, **kwargs):
 
     @check_action_permission('manage_test_comments')
     def destroy(self, request, *args, **kwargs):
-        '''
+        """
         Request: DELETE tests/<test_id>/comments/<meta_id>/?project=<project_id>.
-        '''
+        """
         return super().destroy(request, *args, **kwargs)
diff --git a/bublik/interfaces/api_v2/config/schemas.py b/bublik/interfaces/api_v2/config/schemas.py
index 95459a404..d5dffe2b7 100644
--- a/bublik/interfaces/api_v2/config/schemas.py
+++ b/bublik/interfaces/api_v2/config/schemas.py
@@ -23,12 +23,12 @@
 config_viewset_schema = extend_schema_view(
     list=extend_schema(
         summary='List of configurations',
-        description='''
+        description="""
         Returns a list of configurations.
         Of all configurations having the same project, type and name:
         - If there are active ones, returns active ones
         - If there are none, returns the latest ones
-        ''',
+        """,
         responses={
             200: OpenApiResponse(
                 response=ConfigListResponseSerializer,
@@ -39,9 +39,9 @@
     ),
     create=extend_schema(
         summary='Creates new configuration',
-        description='''
+        description="""
         Creates new configuration. Requires administrator's role.
-        ''',
+        """,
         request=ConfigSerializer,
         responses={
             201: OpenApiResponse(
@@ -61,10 +61,10 @@
     ),
     partial_update=extend_schema(
         summary='Partial update configuration',
-        description='''
+        description="""
         Updates a configuration or creates a new version.
         Requires administrator's role.
-        ''',
+        """,
         request=ConfigPartialUpdateRequestSerializer,
         responses={
             200: OpenApiResponse(
@@ -88,9 +88,9 @@
     ),
     destroy=extend_schema(
         summary='Deletes configuration',
-        description='''
+        description="""
         Deletes a configuration. Requires administrator's role.
-        ''',
+        """,
         responses={
             204: OpenApiResponse(
                 description='Configuration was successfully deleted',
@@ -108,9 +108,9 @@
     ),
     get_schema=extend_schema(
         summary='Retrieves configuration schema',
-        description='''
+        description="""
         Retrieves the JSON schema by passed config type and name.
-        ''',
+        """,
         parameters=[
             OpenApiParameter(
                 name='type',
@@ -168,9 +168,9 @@
     ),
     all_versions=extend_schema(
         summary='All versions of configuration',
-        description='''
+        description="""
         Retrieves all versions of passed configurations.
-        ''',
+        """,
         responses={
             200: OpenApiResponse(
                 response=AllVersionsResponseSerializer,
@@ -185,9 +185,9 @@
     ),
     available_types_names=extend_schema(
         summary='Available configuration types and names',
-        description='''
+        description="""
         Returns a reference list of all configuration types and names.
-        ''',
+        """,
         responses={
             200: OpenApiResponse(
                 response=AvailableTypesNamesResponseSerializer,
diff --git a/bublik/interfaces/api_v2/config/views.py b/bublik/interfaces/api_v2/config/views.py
index 611b0605f..44500569f 100644
--- a/bublik/interfaces/api_v2/config/views.py
+++ b/bublik/interfaces/api_v2/config/views.py
@@ -25,9 +25,9 @@
 
 @config_viewset_schema
 class ConfigViewSet(ModelViewSet):
-    '''
+    """
     API for managing system configurations.
-    '''
+    """
 
     pagination_class = None
     queryset = Config.objects.all()
diff --git a/bublik/interfaces/api_v2/dashboard.py b/bublik/interfaces/api_v2/dashboard.py
index 3718bb21c..d57716f39 100644
--- a/bublik/interfaces/api_v2/dashboard.py
+++ b/bublik/interfaces/api_v2/dashboard.py
@@ -35,10 +35,10 @@ class DashboardViewSet(RetrieveModelMixin, GenericViewSet):
 
     @method_decorator(never_cache)
     def list(self, request):
-        '''
+        """
         Return dashboard data for one day.
         Route: /api/v2/dashboard/?date=yyyy-mm-dd.
-        '''
+        """
         project_id = request.query_params.get('project')
         if not self.prepare_settings(project_id):
             raise ValidationError(self.errors)
@@ -123,7 +123,7 @@ def check_and_apply_settings(self, project_id):
         return bool(not self.errors)
 
     def _extract_payload(self, processed):
-        '''
+        """
         Extract payload from processed handler result.
 
         Args:
@@ -131,7 +131,7 @@ def _extract_payload(self, processed):
 
         Returns:
             Payload dict or None if no payload found
-        '''
+        """
         if isinstance(processed, list) and processed and 'payload' in processed[0]:
             return processed[0]['payload']
         if isinstance(processed, dict) and 'payload' in processed:
@@ -139,7 +139,7 @@ def _extract_payload(self, processed):
         return None
 
     def _prepare_handler_data(self, cell_data):
-        '''
+        """
         Prepare cell data for payload handler consumption.
 
         Payload handlers expect data in specific formats (list of dicts
@@ -151,7 +151,7 @@ def _prepare_handler_data(self, cell_data):
 
         Returns:
             Normalized data structure for payload handler
-        '''
+        """
         if isinstance(cell_data, dict):
             return [cell_data]
         if isinstance(cell_data, list):
@@ -162,7 +162,7 @@ def _prepare_handler_data(self, cell_data):
         return {'value': cell_data}
 
     def _merge_payload_to_cell(self, row, key, cell_data, processed):
-        '''
+        """
         Merge payload from processed handler result back into cell data.
 
         Args:
@@ -170,7 +170,7 @@ def _merge_payload_to_cell(self, row, key, cell_data, processed):
             key: Cell key within the row
             cell_data: Original cell data reference
             processed: Processed data from payload handler
-        '''
+        """
         payload = self._extract_payload(processed)
         if not payload:
             return
@@ -186,7 +186,7 @@ def _merge_payload_to_cell(self, row, key, cell_data, processed):
                 cell_data[0] = {'value': cell_data[0], 'payload': payload}
 
     def _apply_payload_to_dashboard_data(self, data: dict) -> None:
-        '''
+        """
         Apply payload handlers to dashboard cell data for URL generation.
 
         This is a UI-specific operation that adds navigation URLs to dashboard cells.
@@ -196,7 +196,7 @@ def _apply_payload_to_dashboard_data(self, data: dict) -> None:
         Args:
             data: Dashboard data dictionary with 'rows' key containing row data.
                   Modified in-place to add payload information.
-        '''
+        """
         if not hasattr(self, 'payload') or not self.payload.handlers:
             return
 
@@ -220,7 +220,7 @@ def _apply_payload_to_dashboard_data(self, data: dict) -> None:
 
 
 class DashboardPayload:
-    '''
+    """
     Wraps dashboard data with the payload defined in DASHBOARD_PAYLOAD.
 
     Payload provides:
@@ -228,16 +228,14 @@ class DashboardPayload:
       to have button-links for chosen columns;
     - per-project system for giving style to rows;
       style is controlled by css classes and can depend on data in rows.
-    '''
+    """
 
     handlers_available: typing.ClassVar['dict'] = {
         item['const']: item['description']
         for item in ConfigServices.get_schema(
             ConfigTypes.GLOBAL,
             GlobalConfigs.PER_CONF.name,
-        )[
-            'properties'
-        ]['DASHBOARD_COLUMNS']['items']['properties']['payload']['oneOf']
+        )['properties']['DASHBOARD_COLUMNS']['items']['properties']['payload']['oneOf']
     }
 
     def __init__(self):
@@ -260,7 +258,7 @@ def __match_settings_to_methods(self, columns):
         diff = get_difference(payloads, self.handlers_available.keys())
         if diff:
             self.errors.append(
-                f"Unknown value(s) in DASHBOARD_COLUMNS payload: {', '.join(diff)}",
+                f'Unknown value(s) in DASHBOARD_COLUMNS payload: {", ".join(diff)}',
             )
         return bool(not self.errors)
 
diff --git a/bublik/interfaces/api_v2/eventlog/views.py b/bublik/interfaces/api_v2/eventlog/views.py
index 951604523..bb9785da9 100644
--- a/bublik/interfaces/api_v2/eventlog/views.py
+++ b/bublik/interfaces/api_v2/eventlog/views.py
@@ -92,7 +92,7 @@ def status(self, request, pk: str | None = None):
                 meta_results__meta__type='import',
             )
         except ObjectDoesNotExist:
-            msg = 'Run corresponding to the passed Celery task ID doesn\'t exist'
+            msg = "Run corresponding to the passed Celery task ID doesn't exist"
             raise NotFoundError(msg) from None
 
         return Response(
diff --git a/bublik/interfaces/api_v2/importruns/views.py b/bublik/interfaces/api_v2/importruns/views.py
index 99f6fe1ef..0a076a0b5 100644
--- a/bublik/interfaces/api_v2/importruns/views.py
+++ b/bublik/interfaces/api_v2/importruns/views.py
@@ -26,16 +26,16 @@
 
 
 class ImportrunsViewSet(ViewSet):
-    '''
+    """
     ViewSet to import run logs.
-    '''
+    """
 
     @method_decorator(never_cache)
     @action(detail=False, methods=['get', 'post'])
     def source(self, request):
-        '''
+        """
         Creates a Celery task to import a session from the provided URI.
-        '''
+        """
         serializer = ImportrunsSerializer(data=request.query_params)
         serializer.is_valid(raise_exception=True)
 
@@ -64,10 +64,10 @@ def source(self, request):
 
     @action(detail=False, methods=['get'])
     def log(self, request):
-        r'''
+        r"""
         Return import logs in JSON.
         Route: /api/v2/importruns/log/?task_id=<task_id\>.
-        '''
+        """
 
         task_id = request.query_params.get('task_id')
 
@@ -98,7 +98,7 @@ def log(self, request):
     @method_decorator(never_cache)
     @action(detail=False, methods=['post'], renderer_classes=[JSONRenderer])
     def init(self, request, format=None):
-        '''Starts live import initializing run. Returns run identifier.'''
+        """Starts live import initializing run. Returns run identifier."""
         try:
             cache = None
             data = json.loads(request.body)
@@ -128,7 +128,7 @@ def init(self, request, format=None):
     @method_decorator(never_cache)
     @action(detail=False, methods=['post'], renderer_classes=[JSONRenderer])
     def feed(self, request, format=None):
-        '''Accepts chunks of the run tree.'''
+        """Accepts chunks of the run tree."""
         try:
             ctx = None
             cache = None
@@ -181,7 +181,7 @@ def feed(self, request, format=None):
     @method_decorator(never_cache)
     @action(detail=False, methods=['post'], renderer_classes=[JSONRenderer])
     def finish(self, request, format=None):
-        '''Finish a live import session.'''
+        """Finish a live import session."""
         try:
             ctx = None
             cache = None
diff --git a/bublik/interfaces/api_v2/job_task/schemas.py b/bublik/interfaces/api_v2/job_task/schemas.py
index b71989401..281aa1c10 100644
--- a/bublik/interfaces/api_v2/job_task/schemas.py
+++ b/bublik/interfaces/api_v2/job_task/schemas.py
@@ -17,10 +17,10 @@
 job_task_execution_viewset_schema = extend_schema_view(
     retrieve=extend_schema(
         summary='Get task executions by job',
-        description='''
+        description="""
         Returns a list of task execution results for a given job ID.
         Each entry contains the task status, source URL, Celery task UUID, and linked run ID.
-        ''',
+        """,
         responses={
             200: OpenApiResponse(
                 response=JobTaskExecutionRetrieveSerializer(many=True),
@@ -35,11 +35,11 @@
     ),
     list=extend_schema(
         summary='List task executions',
-        description='''
+        description="""
         Returns a paginated list of task execution results with full details:
         timing information, event logs, and an extracted error message for failed tasks.
         Supports filtering by job, run, URL, Celery task UUID, and status.
-        ''',
+        """,
         responses={
             200: OpenApiResponse(
                 response=JobTaskExecutionListSerializer(many=True),
diff --git a/bublik/interfaces/api_v2/job_task/serializers.py b/bublik/interfaces/api_v2/job_task/serializers.py
index d0f09eef8..e64e07743 100644
--- a/bublik/interfaces/api_v2/job_task/serializers.py
+++ b/bublik/interfaces/api_v2/job_task/serializers.py
@@ -7,8 +7,8 @@
 
 
 class JobTaskExecutionListSerializer(serializers.Serializer):
-    '''Serializer for a single task execution entry returned by the list endpoint.
-    Includes full execution details: timing, event logs, and error message.'''
+    """Serializer for a single task execution entry returned by the list endpoint.
+    Includes full execution details: timing, event logs, and error message."""
 
     status = serializers.CharField()
     run_source_url = serializers.CharField()
@@ -23,9 +23,9 @@ class JobTaskExecutionListSerializer(serializers.Serializer):
 
 
 class JobTaskExecutionRetrieveSerializer(serializers.Serializer):
-    '''Serializer for a single task execution entry returned by the retrieve-by-job endpoint.
+    """Serializer for a single task execution entry returned by the retrieve-by-job endpoint.
     Contains only the essential fields: status, source URL, Celery task UUID, and linked run ID.
-    '''
+    """
 
     status = serializers.CharField()
     run_source_url = serializers.CharField()
diff --git a/bublik/interfaces/api_v2/log.py b/bublik/interfaces/api_v2/log.py
index b3a567c5c..6aea694fc 100644
--- a/bublik/interfaces/api_v2/log.py
+++ b/bublik/interfaces/api_v2/log.py
@@ -22,10 +22,10 @@ class LogViewSet(RetrieveModelMixin, GenericViewSet):
 
     @action(detail=True, methods=['get'])
     def json(self, request, pk=None):
-        '''
+        """
         Return the URLs of the corresponding JSON log file and attachments file.
         Route: /api/v2/logs/<ID>/json/?page=<page\\>.
-        '''
+        """
         page_str = request.query_params.get('page')
         page = int(page_str) if page_str else None
         request_origin = request.get_host() if request else None
@@ -37,10 +37,10 @@ def json(self, request, pk=None):
 
     @action(detail=True, methods=['get'])
     def html(self, request, pk=None):
-        '''
+        """
         Return the URL to the corresponding HTML log file.
         Route: /api/v2/logs/<ID>/html/.
-        '''
+        """
 
         # Let LogService handle validation and raise appropriate exceptions
         # The custom exception handler will format the response
@@ -49,10 +49,10 @@ def html(self, request, pk=None):
 
     @action(detail=False, methods=['get'])
     def proxy(self, request):
-        '''
+        """
         Forward the request to the given URL and return the response data.
         Route: /api/v2/logs/proxy/?url=<forwarding_url>
-        '''
+        """
         forward_url = request.query_params.get('url')
 
         # Let LogService handle validation and raise appropriate exceptions
diff --git a/bublik/interfaces/api_v2/performance.py b/bublik/interfaces/api_v2/performance.py
index ee082a5f4..b6f2fee71 100644
--- a/bublik/interfaces/api_v2/performance.py
+++ b/bublik/interfaces/api_v2/performance.py
@@ -18,10 +18,10 @@
 
 class PerformanceCheckView(APIView):
     def get(self, request, *args, **kwargs):
-        '''
+        """
         Return labels, URLs and timeouts for basic views.
         Route: /performance_check.
-        '''
+        """
         views_to_check = [
             'dashboard',
             'runs_list',
diff --git a/bublik/interfaces/api_v2/project.py b/bublik/interfaces/api_v2/project.py
index 86d20f884..a45b2e59c 100644
--- a/bublik/interfaces/api_v2/project.py
+++ b/bublik/interfaces/api_v2/project.py
@@ -65,14 +65,14 @@ def list(self, request, *args, **kwargs):
 
     @action(detail=True, methods=['get'], url_path='badge')
     def badge(self, request, pk=None):
-        '''
+        """
         SVG badge for the latest run of a project.
 
         Query parameters:
             label   (optional) -- left-side text; defaults to project name
             metric  (optional) -- passed | unexpected | total | rate
                                    default shows run conclusion with nok count
-        '''
+        """
         project = self.get_object()
         label = request.query_params.get('label') or project.name
         metric = request.query_params.get('metric', '').lower()
diff --git a/bublik/interfaces/api_v2/report.py b/bublik/interfaces/api_v2/report.py
index 3fb67f5c3..ee9750a81 100644
--- a/bublik/interfaces/api_v2/report.py
+++ b/bublik/interfaces/api_v2/report.py
@@ -23,18 +23,18 @@ class ReportViewSet(RetrieveModelMixin, GenericViewSet):
 
     @action(detail=True, methods=['get'])
     def configs(self, request, pk=None):
-        '''
+        """
         Return a list of active configs that can be used to build a report on the current run.
         Request: GET /api/v2/report/<run_id>/configs
-        '''
+        """
         return Response(
             {'run_report_configs': ReportService.get_configs_for_run_report(self.get_object())},
         )
 
     def retrieve(self, request, pk=None):
-        '''
+        """
         Request: GET /api/v2/report/<run_id>?config=<config_id\\>
-        '''
+        """
         # Check if the config ID has been passed
         report_config_id = request.query_params.get('config')
         if not report_config_id:
diff --git a/bublik/interfaces/api_v2/url_shortener.py b/bublik/interfaces/api_v2/url_shortener.py
index 8d28d399c..d847ecae9 100644
--- a/bublik/interfaces/api_v2/url_shortener.py
+++ b/bublik/interfaces/api_v2/url_shortener.py
@@ -23,11 +23,11 @@
 
 class URLShortenerView(APIView):
     def get(self, request, *args, **kwargs):
-        r'''
+        r"""
         Return a short URL corresponding to the passed URL.
         Short URL format is 'http://<host name>/bublik/short/<view>/<hash>'.
         Route: /url_shortener/?url=<url\>.
-        '''
+        """
         # Get URL to be shortened
         url = self.request.query_params.get('url', '')
 
@@ -35,8 +35,8 @@ def get(self, request, *args, **kwargs):
         url_head = build_absolute_uri(request, settings.UI_PREFIX)
         if url.find(url_head) != 0:
             logger.error(
-                f'URL validation failed: URL \'{url}\' does not start '
-                f'with expected prefix \'{url_head}\'',
+                f"URL validation failed: URL '{url}' does not start "
+                f"with expected prefix '{url_head}'",
             )
             msg = 'The passed URL has an incorrect prefix'
             raise ValidationError(msg)
diff --git a/bublik/interfaces/celery/tasks.py b/bublik/interfaces/celery/tasks.py
index e31c01eec..24dc528aa 100644
--- a/bublik/interfaces/celery/tasks.py
+++ b/bublik/interfaces/celery/tasks.py
@@ -296,13 +296,13 @@ def meta_categorization(self, project_name):
 
 @app.task(bind=True)
 def run_cache(self, *args, **kwargs):
-    '''This is a wrapper to execute an action in the background.'''
+    """This is a wrapper to execute an action in the background."""
     call_command('run_cache', *args, **kwargs)
 
 
 @app.task(bind=True)
 def update_all_hashed_objects(self):
-    '''This is a wrapper to execute an action in the background.'''
+    """This is a wrapper to execute an action in the background."""
     call_command('update_all_hashed_objects')
 
 
diff --git a/bublik/interfaces/management/commands/add_tags.py b/bublik/interfaces/management/commands/add_tags.py
index 89301ad37..5a23cfce7 100644
--- a/bublik/interfaces/management/commands/add_tags.py
+++ b/bublik/interfaces/management/commands/add_tags.py
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (C) 2016-2023 OKTET Labs Ltd. All rights reserved.
-'''
+"""
 This command can be called to add tags to:
 - specified by id run;
 - runs in a specific time range;
@@ -9,7 +9,7 @@
 
 The log_base parameter is required because DB saves only the second part of the
 path to the log. In order to get logs - the url base of log storage is needed.
-'''
+"""
 
 from datetime import datetime, timedelta
 import os
@@ -33,7 +33,7 @@
 
 
 def _get_json_data(url: str) -> dict:
-    '''This methods tries to fetch logs from url.'''
+    """This methods tries to fetch logs from url."""
     process_dir = None
 
     try:
@@ -104,10 +104,10 @@ def add_arguments(self, parser):
 
     @staticmethod
     def process_log_and_update_tags(run: TestIterationResult, log_base_url: str) -> None:
-        '''
+        """
         This method parses the log.json, gets tags from there and adds it to
         the given run.
-        '''
+        """
         try:
             log_meta = MetaResult.objects.get(meta__type='log', result=run.pk).meta
         except ObjectDoesNotExist:
@@ -168,7 +168,7 @@ def handle(self, *args, **options) -> None:
 
             if options['meta']:
                 logger.info(
-                    f"Updating tags for runs associated with Meta: {options['meta']}.",
+                    f'Updating tags for runs associated with Meta: {options["meta"]}.',
                 )
                 runs = runs.filter_by_run_metas([options['meta']])
 
diff --git a/bublik/interfaces/management/commands/assign_project_by_meta.py b/bublik/interfaces/management/commands/assign_project_by_meta.py
index 45b688f90..6b113aa32 100644
--- a/bublik/interfaces/management/commands/assign_project_by_meta.py
+++ b/bublik/interfaces/management/commands/assign_project_by_meta.py
@@ -70,8 +70,7 @@ def is_meta_valid(self, meta_name):
         )
         if runs_with_single_meta_num != runs.count():
             msg = (
-                'Invalid meta name: not all runs are linked '
-                'to exactly one meta with this name.'
+                'Invalid meta name: not all runs are linked to exactly one meta with this name.'
             )
             return False, msg
 
@@ -79,14 +78,14 @@ def is_meta_valid(self, meta_name):
         return True, msg
 
     def get_runs_to_migrate(self, meta_name):
-        '''
+        """
         Returns a queryset of runs for which the name of the linked project
         does not match the value of the meta with the provided name associated with the run.
         Also includes runs that are not yet linked to any project.
 
         This helps identify runs that require project reassignment
         based on the provided meta value.
-        '''
+        """
         self.stdout.write('Checking for runs requiring migration...')
         meta_value_subquery = Meta.objects.filter(
             metaresult__result=OuterRef('pk'),
@@ -110,10 +109,10 @@ def get_runs_to_migrate(self, meta_name):
         )
 
     def get_or_create_project(self, meta):
-        '''
+        """
         Returns the Project instance with the specified name.
         If such a project does not exist, a new one is created.
-        '''
+        """
         try:
             project = Project.objects.get(name=meta.value)
             self.stdout.write(f'\tProject {meta.value} already exist.')
@@ -130,7 +129,7 @@ def get_or_create_project(self, meta):
 
     @transaction.atomic
     def init_project_configs(self, project, runs_to_migrate):
-        '''
+        """
         Initializes configurations for the given project by copying active configurations
         from the projects associated with the runs being reassigned.
 
@@ -140,7 +139,7 @@ def init_project_configs(self, project, runs_to_migrate):
         Only unique configurations (by content) are copied. Conflicting configurations
         are excluded from initialization, and a warning with the conflicting type-name
         pairs is printed.
-        '''
+        """
         project_ids = list(runs_to_migrate.values_list('project', flat=True).distinct())
 
         project_filter = Q()
@@ -197,9 +196,9 @@ def init_project_configs(self, project, runs_to_migrate):
 
     @transaction.atomic
     def update_project_test_comments(self, project, runs_to_migrate_ids):
-        '''
+        """
         Extends the test comments of the given project with those linked to the provided runs.
-        '''
+        """
         self.stdout.write('\tMigrate test comments:')
         meta_test_comments = (
             MetaTest.objects.filter(
@@ -226,11 +225,11 @@ def update_project_test_comments(self, project, runs_to_migrate_ids):
         )
 
     def reassign_runs_to_project(self, project, runs_to_migrate_ids):
-        '''
+        """
         Assigns the specified runs and their linked results to the given project.
 
         Processes the update in batches to optimize performance and ensure atomicity.
-        '''
+        """
         self.stdout.write('\tMigrate runs:')
         self.stdout.write(
             f'\tThe number of runs to migrate: {len(runs_to_migrate_ids)}',
diff --git a/bublik/interfaces/management/commands/checkintegrity.py b/bublik/interfaces/management/commands/checkintegrity.py
index 633527cfc..d86de127e 100644
--- a/bublik/interfaces/management/commands/checkintegrity.py
+++ b/bublik/interfaces/management/commands/checkintegrity.py
@@ -228,9 +228,9 @@ def __verify_database(self, stats_trc, log_gist):
                 continue
 
             if reduce(
-                lambda acc, t: acc
-                and t.name in log_gist.tags
-                and log_gist.tags[t.name] == t.value,
+                lambda acc, t: (
+                    acc and t.name in log_gist.tags and log_gist.tags[t.name] == t.value
+                ),
                 tags,
                 True,
             ):
diff --git a/bublik/interfaces/management/commands/cleanup_db.py b/bublik/interfaces/management/commands/cleanup_db.py
index 625fa4e2b..4b0207ca4 100644
--- a/bublik/interfaces/management/commands/cleanup_db.py
+++ b/bublik/interfaces/management/commands/cleanup_db.py
@@ -18,9 +18,9 @@
 
 class Command(BaseCommand):
     def delete_duplicate_mmr(self):
-        '''
+        """
         Delete duplicate MeasurementResult objects.
-        '''
+        """
         self.stdout.write('Delete duplicate MeasurementResult objects:')
         mmr_dups_iterator = (
             MeasurementResult.objects.values('result', 'serial', 'measurement', 'value')
@@ -47,10 +47,10 @@ def delete_duplicate_mmr(self):
         )
 
     def move_mmr_sequences(self):
-        '''
+        """
         Find sequences among MeasurementResult objects and move them
         to the MeasurementResultList.
-        '''
+        """
         self.stdout.write('Move measurement result sequences:')
 
         mmrl_start_num = MeasurementResultList.objects.count()
@@ -125,10 +125,10 @@ def move_mmr_sequences(self):
         )
 
     def delete_incorrect_cv(self):
-        '''
+        """
         Delete type X and Y ChartView objects linking unit measurements to line-graph
         type views.
-        '''
+        """
         self.stdout.write('Delete incorrect ChartView objects:')
 
         deleted_cv_count, _ = (
@@ -157,9 +157,9 @@ def delete_incorrect_cv(self):
         )
 
     def delete_duplicate_cv(self):
-        '''
+        """
         Delete duplicate ChartView objects.
-        '''
+        """
         self.stdout.write('Delete duplicate ChartView objects:')
 
         cv_dups = (
@@ -185,9 +185,9 @@ def delete_duplicate_cv(self):
         )
 
     def delete_unused_views(self):
-        '''
+        """
         Delete View objects that are not referenced by any ChartView object.
-        '''
+        """
         self.stdout.write('Delete unused View objects:')
 
         unused, _ = View.objects.exclude(
diff --git a/bublik/interfaces/management/commands/delete_run.py b/bublik/interfaces/management/commands/delete_run.py
index 480edcc09..905361108 100644
--- a/bublik/interfaces/management/commands/delete_run.py
+++ b/bublik/interfaces/management/commands/delete_run.py
@@ -10,8 +10,8 @@
 
 
 class Command(BaseCommand):
-    help = '''COMPLETELY DELETE all runs satisfying the given parameters.
-              This action CANNOT be UNDONE. Related cache will be also deleted.'''
+    help = """COMPLETELY DELETE all runs satisfying the given parameters.
+              This action CANNOT be UNDONE. Related cache will be also deleted."""
 
     def add_arguments(self, parser):
         parser.add_argument(
@@ -34,7 +34,7 @@ def add_arguments(self, parser):
         )
 
     def handle(self, *args, **options):
-        '''Delete only runs, not any test iteration result.'''
+        """Delete only runs, not any test iteration result."""
 
         try:
             query = Q()
diff --git a/bublik/interfaces/management/commands/fix_result_timestamps.py b/bublik/interfaces/management/commands/fix_result_timestamps.py
index 129a7964a..54c86bd21 100644
--- a/bublik/interfaces/management/commands/fix_result_timestamps.py
+++ b/bublik/interfaces/management/commands/fix_result_timestamps.py
@@ -1,4 +1,4 @@
-'''
+"""
 Management command: fix_result_timestamps
 Usage: python manage.py fix_result_timestamps [-i <id> ...] [-f <date>] [-t <date>]
 
@@ -105,7 +105,7 @@
       suppressed (terminal_only=True).
     - In a terminal (manage.py): writes to stdout with indentation and colour.
       The first letter of each label is capitalised automatically.
-'''
+"""
 
 from __future__ import annotations
 
@@ -151,7 +151,7 @@
 
 
 class RunResult(NamedTuple):
-    '''
+    """
     Categorisation of a single run after the full pipeline.
 
     Attributes:
@@ -165,7 +165,7 @@ class RunResult(NamedTuple):
             was reached.
         error_msg: Human-readable failure description, or None if the run
             succeeded or was skipped (no_data, null_timestamps).
-    '''
+    """
 
     skipped_reason: SkippedReason | None
     midnight_fix_status: FixStatus | None
@@ -179,19 +179,19 @@ class RunResult(NamedTuple):
 
 
 def _get_delta_start(run_start: datetime, first_pkg_start: datetime) -> timedelta:
-    '''
+    """
     Return the largest whole-hour timedelta H such that
     (first_pkg_start - H) >= run_start.
-    '''
+    """
     diff_seconds = (first_pkg_start - run_start).total_seconds()
     return timedelta(hours=math.floor(diff_seconds / 3600))
 
 
 def _get_delta_finish(run_finish: datetime, last_pkg_finish: datetime) -> timedelta:
-    '''
+    """
     Return the smallest whole-hour timedelta H such that
     (last_pkg_finish - H) <= run_finish.
-    '''
+    """
     diff_seconds = (last_pkg_finish - run_finish).total_seconds()
     return timedelta(hours=math.ceil(diff_seconds / 3600))
 
@@ -204,7 +204,7 @@ def _get_delta_finish(run_finish: datetime, last_pkg_finish: datetime) -> timede
 def _children_map(
     run_results: list[TestIterationResult],
 ) -> dict[int, list[TestIterationResult]]:
-    '''
+    """
     Build a parent_pk -> [children] map for the full run tree, with run as
     the virtual root.
 
@@ -214,7 +214,7 @@ def _children_map(
 
     Children lists are sorted by (exec_seqno, pk) to guarantee a stable,
     deterministic traversal order independent of dict insertion order.
-    '''
+    """
     children: dict[int, list[TestIterationResult]] = defaultdict(list)
 
     for result in run_results:
@@ -248,7 +248,7 @@ def _fix_run_tree(
     children_map: dict[int, list[TestIterationResult]],
     changed: set[int],
 ) -> None:
-    '''
+    """
     DFS traversal that fixes midnight-crossing errors in the full run tree.
     run is the virtual root used only for traversal entry and parent_start
     anchoring; its finish is never modified.
@@ -280,10 +280,10 @@ def _fix_run_tree(
     second iteration (when it becomes `prev`), not immediately after
     _visit(first) — the effect is the same because no sibling comparison
     happens before that point.
-    '''
+    """
 
     def _fix_start(node: TestIterationResult, prev_timestamp: datetime) -> None:
-        '''Align node.start with prev_timestamp by +-1 day if the gap is wrong.'''
+        """Align node.start with prev_timestamp by +-1 day if the gap is wrong."""
         if node.start < prev_timestamp:
             node.start += ONE_DAY
             changed.add(node.pk)
@@ -304,7 +304,7 @@ def _fix_start(node: TestIterationResult, prev_timestamp: datetime) -> None:
                 raise ValueError(msg)
 
     def _fix_finish(node: TestIterationResult, prev_timestamp: datetime) -> None:
-        '''Align node.finish with prev_timestamp by +-1 day if the gap is wrong.'''
+        """Align node.finish with prev_timestamp by +-1 day if the gap is wrong."""
         if node.finish is None:
             return
         if node.finish < prev_timestamp:
@@ -327,12 +327,12 @@ def _fix_finish(node: TestIterationResult, prev_timestamp: datetime) -> None:
                 raise ValueError(msg)
 
     def _fix_self_finish(node: TestIterationResult, is_leaf: bool) -> None:
-        '''
+        """
         Align node.finish with node.start by +-1 day if the gap is wrong.
 
         For leaf nodes: both finish < start and finish - start >= 24h are fixed.
         For non-leaf nodes: only finish < start is fixed.
-        '''
+        """
         if node.finish is None:
             return
         if node.finish < node.start:
@@ -435,7 +435,7 @@ def _log(
         terminal_only: bool = False,
         logger_only: bool = False,
     ) -> None:
-        '''
+        """
         Route output to the task logger or stdout depending on context.
 
         Writes to the task logger when TASK_ID env var is set (Celery task),
@@ -461,7 +461,7 @@ def _log(
                            Use for messages that are only meaningful in a task
                            context (e.g. final success confirmation already
                            implied by the terminal status line).
-        '''
+        """
         if os.getenv('TASK_ID') is not None:
             if not terminal_only:
                 msg = f'{label}: {value}' if value else label
@@ -688,7 +688,7 @@ def handle(self, *args, **options):
         self.stdout.write('\n=========================================================')
 
     def _fix_run(self, run) -> RunResult:
-        '''
+        """
         Apply both correction stages to one run following the pipeline:
 
           0. Unable-to-process checks (no data, null timestamps).
@@ -706,7 +706,7 @@ def _fix_run(self, run) -> RunResult:
         rolled back, so no database writes from Stage 1 persist. A Stage 2
         fix error leaves Stage 1 changes intact unless the final sanity
         check triggers a full rollback.
-        '''
+        """
         run_results = TestIterationResult.objects.filter(test_run_id=run.pk).order_by(
             'exec_seqno',
             'pk',
diff --git a/bublik/interfaces/management/commands/initialize_configs.py b/bublik/interfaces/management/commands/initialize_configs.py
index 0af716697..0caf74ca3 100644
--- a/bublik/interfaces/management/commands/initialize_configs.py
+++ b/bublik/interfaces/management/commands/initialize_configs.py
@@ -16,9 +16,9 @@
 
 class Command(BaseCommand):
     def handle(self, *args, **options):
-        '''
+        """
         Initialize default required configurations from JSON schemas.
-        '''
+        """
 
         self.stdout.write('Initialize default required configurations if they do not exist:')
         for config in GlobalConfigs.required():
diff --git a/bublik/interfaces/management/commands/meta_categorization.py b/bublik/interfaces/management/commands/meta_categorization.py
index 4d114d924..880fb2fc9 100644
--- a/bublik/interfaces/management/commands/meta_categorization.py
+++ b/bublik/interfaces/management/commands/meta_categorization.py
@@ -21,7 +21,7 @@
 
 
 class Command(BaseCommand):
-    '''
+    """
     Example of config content handled by the command:
     [
         "Configuration": {
@@ -40,7 +40,7 @@ class Command(BaseCommand):
             "set-priority": 10
         }
     ]
-    '''
+    """
 
     help = 'Assign a class and a priority to the metas in the database'
 
diff --git a/bublik/interfaces/management/commands/migrate_configs.py b/bublik/interfaces/management/commands/migrate_configs.py
index 0bf5a4b74..ac082d13d 100644
--- a/bublik/interfaces/management/commands/migrate_configs.py
+++ b/bublik/interfaces/management/commands/migrate_configs.py
@@ -21,9 +21,9 @@
 
 
 def any_config_file_exists(config_file_names):
-    '''
+    """
     Check the existence of the PER_CONF_DIR directory and the presence of passed files in it.
-    '''
+    """
     config_file_paths = [
         os.path.join(settings.PER_CONF_DIR, config_file_name)
         for config_file_name in config_file_names
@@ -71,9 +71,9 @@ def migrate_config(
         config_content,
         config_description=None,
     ):
-        '''
+        """
         Create global config object with passed name, description and content.
-        '''
+        """
         configs = Config.objects.filter(
             type=ConfigTypes.GLOBAL,
             name=config_name,
diff --git a/bublik/interfaces/management/commands/migrate_tags_config_to_meta.py b/bublik/interfaces/management/commands/migrate_tags_config_to_meta.py
index 0834d7c32..b88f4bea3 100644
--- a/bublik/interfaces/management/commands/migrate_tags_config_to_meta.py
+++ b/bublik/interfaces/management/commands/migrate_tags_config_to_meta.py
@@ -23,7 +23,6 @@ def check_duplicates(config):
 
 
 class Command(BaseCommand):
-
     @transaction.atomic()
     def handle(self, *args, **options):
 
diff --git a/bublik/interfaces/management/commands/prune_analytics.py b/bublik/interfaces/management/commands/prune_analytics.py
index 9271eec6b..776207266 100644
--- a/bublik/interfaces/management/commands/prune_analytics.py
+++ b/bublik/interfaces/management/commands/prune_analytics.py
@@ -63,9 +63,9 @@ def handle(self, *args, **options):
 
         self.stdout.write(
             self.style.SUCCESS(
-                "Analytics prune completed: "
-                f"deleted_by_age={result['deleted_by_age']}, "
-                f"deleted_by_cap={result['deleted_by_cap']}, "
-                f"remaining={result['remaining']}",
+                'Analytics prune completed: '
+                f'deleted_by_age={result["deleted_by_age"]}, '
+                f'deleted_by_cap={result["deleted_by_cap"]}, '
+                f'remaining={result["remaining"]}',
             ),
         )
diff --git a/bublik/interfaces/management/commands/reformat_configs.py b/bublik/interfaces/management/commands/reformat_configs.py
index e2ac730f9..7ae8209fe 100644
--- a/bublik/interfaces/management/commands/reformat_configs.py
+++ b/bublik/interfaces/management/commands/reformat_configs.py
@@ -15,9 +15,9 @@
 
 class Command(BaseCommand):
     def get_configs(self, options):
-        '''
+        """
         Get a list of configurations filtered by the passed types and names.
-        '''
+        """
         configs = Config.objects.all().order_by(
             'project',
             '-is_active',
diff --git a/bublik/interfaces/management/commands/reset_run_statuses.py b/bublik/interfaces/management/commands/reset_run_statuses.py
index 04aa534f0..37f6c40d4 100644
--- a/bublik/interfaces/management/commands/reset_run_statuses.py
+++ b/bublik/interfaces/management/commands/reset_run_statuses.py
@@ -12,7 +12,7 @@
 
 
 def define_run_status(run):
-    '''Function to define existing run status'''
+    """Function to define existing run status"""
 
     category_names = ['DL', 'DU', 'Status', 'Notes']
     run_meta_results = run.meta_results.select_related('meta')
@@ -65,9 +65,9 @@ def run_error():
 
 
 class Command(BaseCommand):
-    help = '''Reset existing run statuses to the one of the following values:
+    help = """Reset existing run statuses to the one of the following values:
               ['DONE', 'ERROR', 'WARNING', 'RUNNING']
-              for runs satisfying the given parameters.'''
+              for runs satisfying the given parameters."""
 
     def add_arguments(self, parser):
         parser.add_argument(
diff --git a/bublik/interfaces/management/commands/run_cache.py b/bublik/interfaces/management/commands/run_cache.py
index 8ebf43e83..4d8a10ec7 100644
--- a/bublik/interfaces/management/commands/run_cache.py
+++ b/bublik/interfaces/management/commands/run_cache.py
@@ -15,9 +15,9 @@
 
 
 class Command(BaseCommand):
-    help = '''DELETE, CREATE or UPDATE cached data for runs satisfying the given parameters.
+    help = """DELETE, CREATE or UPDATE cached data for runs satisfying the given parameters.
               Cached data for managing can be controlled by --data option.
-              By default cache action is applyied to all runs.'''
+              By default cache action is applyied to all runs."""
 
     def add_arguments(self, parser):
         parser.add_argument(
diff --git a/bublik/interfaces/management/commands/run_mcp_server.py b/bublik/interfaces/management/commands/run_mcp_server.py
index 872aa41ee..dcd175997 100644
--- a/bublik/interfaces/management/commands/run_mcp_server.py
+++ b/bublik/interfaces/management/commands/run_mcp_server.py
@@ -23,7 +23,7 @@ def add_arguments(self, parser):
         )
 
     def handle(self, *args, **options):
-        self.stdout.write(f"Starting Bublik MCP server on {options['host']}:{options['port']}")
+        self.stdout.write(f'Starting Bublik MCP server on {options["host"]}:{options["port"]}')
 
         mcp = create_mcp_server()
 
diff --git a/bublik/interfaces/management/commands/update_all_hashed_objects.py b/bublik/interfaces/management/commands/update_all_hashed_objects.py
index c75af2624..eb3f34dc1 100644
--- a/bublik/interfaces/management/commands/update_all_hashed_objects.py
+++ b/bublik/interfaces/management/commands/update_all_hashed_objects.py
@@ -14,7 +14,7 @@
 
 class Command(BaseCommand):
     def handle(self, *args, **options):
-        '''The order of hashed models updating is valuable.'''
+        """The order of hashed models updating is valuable."""
 
         hashed_models = [
             MetaSerializer,
diff --git a/bublik/mcp/models.py b/bublik/mcp/models.py
index 3393943f5..f23850daf 100644
--- a/bublik/mcp/models.py
+++ b/bublik/mcp/models.py
@@ -296,9 +296,9 @@ class JsonLog(BaseModel):
 
 
 class LogLine(BaseModel):
-    '''
+    """
     Single log line with markdown conversion support.
-    '''
+    """
 
     line_number: int
     level: str
@@ -315,7 +315,7 @@ class LogLine(BaseModel):
     table_index: int = 0  # Index of source te-log-table block
 
     def truncate_content(self, max_length: int) -> LogLine:
-        '''
+        """
         Create a copy with truncated content.
 
         Args:
@@ -323,7 +323,7 @@ def truncate_content(self, max_length: int) -> LogLine:
 
         Returns:
             New LogLine with truncated content and metadata
-        '''
+        """
         if len(self.content) <= max_length:
             return self
 
@@ -336,7 +336,7 @@ def truncate_content(self, max_length: int) -> LogLine:
         )
 
     def to_markdown(self, max_content_length: int | None = None) -> str:
-        '''
+        """
         Convert to markdown table row.
 
         Args:
@@ -344,7 +344,7 @@ def to_markdown(self, max_content_length: int | None = None) -> str:
 
         Returns:
             Markdown table row string
-        '''
+        """
         content = self.content
 
         if (
@@ -366,12 +366,12 @@ def to_markdown(self, max_content_length: int | None = None) -> str:
         )
 
     def to_markdown_full(self) -> str:
-        '''
+        """
         Convert to full markdown block with all details.
 
         Returns:
             Full markdown representation of the log line
-        '''
+        """
         lines = [
             f'### Line {self.line_number}',
             f'- **Level:** {self.level}',
@@ -395,16 +395,16 @@ def to_markdown_full(self) -> str:
 
 
 class LogLinesResult(BaseModel):
-    '''
+    """
     Result of line extraction/filtering with markdown support.
-    '''
+    """
 
     lines: list[LogLine]
     total_count: int
     filter_applied: str | None = None  # Description of filter
 
     def to_markdown(self, max_content_length: int | None = None) -> str:
-        '''
+        """
         Convert to markdown table with separate tables per te-log-table block.
 
         Args:
@@ -412,7 +412,7 @@ def to_markdown(self, max_content_length: int | None = None) -> str:
 
         Returns:
             Markdown table string with separate tables grouped by table_index
-        '''
+        """
         if not self.lines:
             result = ['| Line | Depth | Level | Entity:User | Time | Content |']
             result.append('|------|-------|-------|-------------|------|---------|')
@@ -446,12 +446,12 @@ def to_markdown(self, max_content_length: int | None = None) -> str:
         return '\n'.join(result)
 
     def to_markdown_summary(self) -> str:
-        '''
+        """
         Convert to summary with counts by level.
 
         Returns:
             Markdown summary string
-        '''
+        """
 
         level_counts = Counter(line.level for line in self.lines)
         lines = [
@@ -468,9 +468,9 @@ def to_markdown_summary(self) -> str:
 
 
 class LogHeaderInfo(BaseModel):
-    '''
+    """
     Metadata from a single te-log-meta block.
-    '''
+    """
 
     test_id: str
     test_name: str
@@ -492,9 +492,9 @@ class LogHeaderInfo(BaseModel):
 
 
 class LogOverview(BaseModel):
-    '''
+    """
     Log overview with full metadata and markdown conversion support.
-    '''
+    """
 
     # Identity (from LogEntityModel)
     test_id: str
@@ -534,12 +534,12 @@ class LogOverview(BaseModel):
     scenario_lines: list[LogLine] = Field(default_factory=list)
 
     def to_markdown(self) -> str:  # noqa: C901
-        '''
+        """
         Convert to full markdown document with tables.
 
         Returns:
             Complete markdown representation of the log overview
-        '''
+        """
         sections = []
 
         # Header
@@ -687,12 +687,12 @@ def to_markdown(self) -> str:  # noqa: C901
         return '\n'.join(sections)
 
     def to_markdown_summary(self) -> str:
-        '''
+        """
         Convert to brief markdown summary.
 
         Returns:
             Brief markdown summary
-        '''
+        """
         sections = [
             f'# {self.test_name}',
             '',
diff --git a/bublik/mcp/processor.py b/bublik/mcp/processor.py
index 1323ebc16..523de79ac 100644
--- a/bublik/mcp/processor.py
+++ b/bublik/mcp/processor.py
@@ -1,9 +1,9 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (C) 2025-2026 OKTET Labs Ltd. All rights reserved.
 
-'''
+"""
 Log processor for working with validated JsonLog data.
-'''
+"""
 
 from __future__ import annotations
 
@@ -26,16 +26,16 @@
 
 
 def get_log_timestamp_seconds(timestamp: LogTimestamp) -> float:
-    '''
+    """
     Get Unix timestamp seconds from legacy and numeric JSON log timestamp shapes.
-    '''
+    """
     return timestamp if isinstance(timestamp, float) else timestamp.timestamp
 
 
 def get_log_timestamp_display(timestamp: LogTimestamp) -> str:
-    '''
+    """
     Get formatted display time from legacy and numeric JSON log timestamp shapes.
-    '''
+    """
     if not isinstance(timestamp, float):
         return timestamp.formatted
 
@@ -43,7 +43,7 @@ def get_log_timestamp_display(timestamp: LogTimestamp) -> str:
 
 
 class LogProcessor:
-    '''
+    """
     Process validated JsonLog with extraction and filtering capabilities.
 
     This class takes a validated JsonLog Pydantic model and provides methods
@@ -55,17 +55,17 @@ class LogProcessor:
         >>> processor = LogProcessor(log)
         >>> overview = processor.get_overview(include_scenario=True)
         >>> print(overview.to_markdown())
-    '''
+    """
 
     SCENARIO_USERS: ClassVar[list[str]] = ['Step', 'Artifact', 'Self', 'Verdict']
 
     def __init__(self, log: JsonLog):
-        '''
+        """
         Initialize LogProcessor with validated JsonLog.
 
         Args:
             log: Validated JsonLog Pydantic model instance
-        '''
+        """
         self.log = log
         self._flat_lines: list[LogLine] | None = None
         self._main_entity: str | None = None
@@ -77,19 +77,19 @@ def __init__(self, log: JsonLog):
 
     @property
     def flat_lines(self) -> list[LogLine]:
-        '''
+        """
         Lazily flatten all nested log lines into a flat list.
 
         Returns:
             List of LogLine instances from all log table blocks
-        '''
+        """
         if self._flat_lines is None:
             self._flat_lines = self._flatten_all_lines()
         return self._flat_lines
 
     @property
     def main_test_entity(self) -> str | None:
-        '''
+        """
         Identify the main test entity from log lines.
 
         The main entity is determined by (in priority order):
@@ -101,7 +101,7 @@ def main_test_entity(self) -> str | None:
 
         Returns:
             Main test entity name or None if no lines exist
-        '''
+        """
         if self._main_entity is None:
             if not self.flat_lines:
                 return None
@@ -125,18 +125,18 @@ def main_test_entity(self) -> str | None:
 
     @property
     def all_entity_user_pairs(self) -> list[str]:
-        '''
+        """
         Get all unique entity:user combinations from log lines.
 
         Returns:
             Sorted list of "entity_name:user_name" strings
-        '''
+        """
         pairs = {f'{line.entity_name}:{line.user_name}' for line in self.flat_lines}
         return sorted(pairs)
 
     @property
     def scenario_filters(self) -> list[str]:
-        '''
+        """
         Get entity:user pairs for scenario filter.
 
         Scenario filter includes:
@@ -148,7 +148,7 @@ def scenario_filters(self) -> list[str]:
 
         Returns:
             List of "entity_name:user_name" strings for scenario filtering
-        '''
+        """
         main_entity = self.main_test_entity
         if not main_entity:
             return []
@@ -177,7 +177,7 @@ def get_overview(
         include_scenario: bool = True,
         max_content_length: int | None = None,
     ) -> LogOverview:
-        '''
+        """
         Extract full log overview with metadata from all te-log-meta blocks.
 
         Args:
@@ -190,7 +190,7 @@ def get_overview(
 
         Raises:
             ValueError: If no header block is found in the log
-        '''
+        """
         # Collect ALL header blocks and pagination
         headers: list = []
         pagination = None
@@ -315,7 +315,7 @@ def get_lines(
         table_index: int = 0,
         max_content_length: int | None = 1200,
     ) -> LogLinesResult:
-        '''
+        """
         Extract and filter lines from log.
 
         Supports both range-based filtering (by line numbers) and content-based
@@ -333,7 +333,7 @@ def get_lines(
 
         Returns:
             LogLinesResult with filtered and optionally truncated lines
-        '''
+        """
         lines = self.flat_lines
 
         # Apply all filters (range and content)
@@ -364,7 +364,7 @@ def get_lines(
         # Build comprehensive filter description
         filter_parts = []
         if start_line is not None or end_line is not None:
-            filter_parts.append(f"lines {start_line or 'start'}-{end_line or 'end'}")
+            filter_parts.append(f'lines {start_line or "start"}-{end_line or "end"}')
         if levels:
             filter_parts.append(f'levels={levels}')
         if entity_names:
@@ -383,7 +383,7 @@ def get_lines(
         )
 
     def _add_parent_context(self, lines: list[LogLine]) -> list[LogLine]:
-        '''
+        """
         Add parent lines for all lines in the list.
 
         For each line with a parent, find and include the parent line.
@@ -394,7 +394,7 @@ def _add_parent_context(self, lines: list[LogLine]) -> list[LogLine]:
 
         Returns:
             List with original lines plus all parent lines, sorted by line_number
-        '''
+        """
         # Create a lookup map from all flat lines for parent reference
         line_map = {line.line_number: line for line in self.flat_lines}
 
@@ -424,7 +424,7 @@ def _add_parent_context(self, lines: list[LogLine]) -> list[LogLine]:
         return result
 
     def get_scenario_lines(self, max_content_length: int | None = 200) -> LogLinesResult:
-        '''
+        """
         Get scenario-related log lines.
 
         Scenario lines include: Step, Artifact, Self, Verdict from main entity,
@@ -435,7 +435,7 @@ def get_scenario_lines(self, max_content_length: int | None = 200) -> LogLinesRe
 
         Returns:
             LogLinesResult containing scenario lines
-        '''
+        """
         filters = self.scenario_filters
         if not filters:
             return LogLinesResult(
@@ -462,12 +462,12 @@ def get_scenario_lines(self, max_content_length: int | None = 200) -> LogLinesRe
         )
 
     def get_test_lines(self) -> LogLinesResult:
-        '''
+        """
         Get all lines from the main test entity.
 
         Returns:
             LogLinesResult containing all lines from main test entity
-        '''
+        """
         main_entity = self.main_test_entity
         if not main_entity:
             return LogLinesResult(
@@ -490,13 +490,13 @@ def get_test_lines(self) -> LogLinesResult:
     # =========================================================================
 
     def _flatten_all_lines(self) -> list[LogLine]:
-        '''
+        """
         Flatten all log table data into LogLine instances.
 
         Returns:
             List of LogLine instances from all log table blocks,
             each with table_index indicating source table.
-        '''
+        """
         lines = []
         table_index = 0
         for page_block in self.log.root:
@@ -518,7 +518,7 @@ def _flatten_table_data(
         parent_line_number: int | None = None,
         table_index: int = 0,
     ) -> list[LogLine]:
-        '''
+        """
         Recursively flatten log table data with depth and table tracking.
 
         Args:
@@ -529,7 +529,7 @@ def _flatten_table_data(
 
         Returns:
             Flattened list of LogLine instances
-        '''
+        """
         lines = []
         for item in data:
             # Extract level as string
@@ -565,7 +565,7 @@ def _flatten_table_data(
         return lines
 
     def _escape_markdown_table_cell(self, text: str) -> str:
-        '''
+        """
         Escape pipe characters for markdown tables.
 
         Args:
@@ -573,11 +573,11 @@ def _escape_markdown_table_cell(self, text: str) -> str:
 
         Returns:
             Escaped text with | replaced by \\|
-        '''
+        """
         return str(text).replace('|', '\\|')
 
     def _format_file_block(self, content: str) -> str:
-        '''
+        """
         Format file content in a code block.
 
         Args:
@@ -585,12 +585,12 @@ def _format_file_block(self, content: str) -> str:
 
         Returns:
             Markdown code block with escaped backticks
-        '''
+        """
         escaped = content.replace('```', '\\`\\`\\`')
         return f'```\n{escaped}\n```'
 
     def _format_memory_dump_table(self, dump: list[list[str]]) -> str:
-        '''
+        """
         Format memory dump as a markdown table.
 
         Args:
@@ -598,7 +598,7 @@ def _format_memory_dump_table(self, dump: list[list[str]]) -> str:
 
         Returns:
             Markdown table with memory dump data
-        '''
+        """
         if not dump:
             return '| (empty memory dump) |'
 
@@ -615,7 +615,7 @@ def _format_memory_dump_table(self, dump: list[list[str]]) -> str:
         return '\n'.join(lines)
 
     def _format_sniffer_table(self, content: list[SnifferContentItem]) -> str:
-        '''
+        """
         Format packet sniffer content as an expanded table.
 
         Args:
@@ -623,7 +623,7 @@ def _format_sniffer_table(self, content: list[SnifferContentItem]) -> str:
 
         Returns:
             Markdown table with expanded sniffer items
-        '''
+        """
         if not content:
             return '| (empty packet sniffer) |'
 
@@ -642,7 +642,7 @@ def _format_sniffer_table(self, content: list[SnifferContentItem]) -> str:
         return '\n'.join(lines)
 
     def _extract_content(self, log_content: list[LogContent]) -> str:
-        '''
+        """
         Extract text content from log_content blocks.
 
         Args:
@@ -650,7 +650,7 @@ def _extract_content(self, log_content: list[LogContent]) -> str:
 
         Returns:
             Combined text content string with markdown tables for complex types
-        '''
+        """
         texts = []
         for block in log_content:
             if block.type == 'te-log-table-content-text':
@@ -671,7 +671,7 @@ def _extract_content(self, log_content: list[LogContent]) -> str:
         return '\n\n'.join(texts)
 
     def _get_content_type(self, log_content: list[LogContent]) -> str:
-        '''
+        """
         Determine the primary content type from log_content blocks.
 
         Args:
@@ -680,7 +680,7 @@ def _get_content_type(self, log_content: list[LogContent]) -> str:
         Returns:
             Content type string: "text", "file", "measurement", "memory_dump",
             "packet", or "mixed"
-        '''
+        """
         if not log_content:
             return 'empty'
 
diff --git a/bublik/mcp/tests/conftest.py b/bublik/mcp/tests/conftest.py
index cb0fddfac..0873681b7 100644
--- a/bublik/mcp/tests/conftest.py
+++ b/bublik/mcp/tests/conftest.py
@@ -24,7 +24,7 @@
 
 
 def normalize_dynamic_content(content: str) -> str:
-    '''
+    """
     Normalize dynamic content for stable snapshots.
 
     This function normalizes timestamps and other dynamic values
@@ -35,7 +35,7 @@ def normalize_dynamic_content(content: str) -> str:
 
     Returns:
         Normalized content with stable placeholders
-    '''
+    """
     # Normalize ISO timestamps: 2025-01-15T10:00:00.000Z -> <TIMESTAMP>
     content = re.sub(
         r'\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z',
@@ -54,15 +54,15 @@ def normalize_dynamic_content(content: str) -> str:
 
 
 class MarkdownSnapshotExtension(SingleFileSnapshotExtension):
-    '''
+    """
     Syrupy extension for markdown snapshot files.
-    '''
+    """
 
     _file_extension = 'md'
     _write_mode = WriteMode.TEXT
 
     def serialize(self, data: str, **_kwargs) -> str:
-        '''
+        """
         Serialize data to markdown format.
 
         Args:
@@ -70,13 +70,13 @@ def serialize(self, data: str, **_kwargs) -> str:
 
         Returns:
             Serialized markdown string
-        '''
+        """
         return str(data)
 
 
 @pytest.fixture
 def snapshot_md(snapshot: SnapshotAssertion) -> SnapshotAssertion:
-    '''
+    """
     Fixture providing markdown snapshot assertion.
 
     Args:
@@ -84,18 +84,18 @@ def snapshot_md(snapshot: SnapshotAssertion) -> SnapshotAssertion:
 
     Returns:
         Snapshot assertion configured for markdown files
-    '''
+    """
     return snapshot.use_extension(MarkdownSnapshotExtension)
 
 
 @pytest.fixture
 def single_example_log() -> JsonLog:
-    '''
+    """
     Load comprehensive.json for tests.
 
     Returns:
         Validated JsonLog instance
-    '''
+    """
     example_file = EXAMPLES_DIR / 'comprehensive.json'
     if not example_file.exists():
         pytest.skip(f'Example file not found: {example_file}')
@@ -107,7 +107,7 @@ def single_example_log() -> JsonLog:
 
 @pytest.fixture
 def single_processor(single_example_log: JsonLog) -> LogProcessor:
-    '''
+    """
     Create LogProcessor from comprehensive.json.
 
     Args:
@@ -115,5 +115,5 @@ def single_processor(single_example_log: JsonLog) -> LogProcessor:
 
     Returns:
         LogProcessor instance
-    '''
+    """
     return LogProcessor(single_example_log)
diff --git a/bublik/mcp/tests/test_log_processor_snapshots.py b/bublik/mcp/tests/test_log_processor_snapshots.py
index 1e70a51d8..9fe041c4a 100644
--- a/bublik/mcp/tests/test_log_processor_snapshots.py
+++ b/bublik/mcp/tests/test_log_processor_snapshots.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (C) 2025-2026 OKTET Labs Ltd. All rights reserved.
 
-'''
+"""
 Snapshot tests for LogProcessor markdown output.
 
 This module uses syrupy for snapshot testing to verify that LogProcessor
@@ -12,7 +12,7 @@
 
 Update snapshots after intentional changes:
     pytest bublik/mcp/tests/test_log_processor_snapshots.py --snapshot-update
-'''
+"""
 
 from __future__ import annotations
 
@@ -28,18 +28,18 @@
 
 
 class TestOverviewSnapshots:
-    '''
+    """
     Snapshot tests for get_overview method.
-    '''
+    """
 
     def test_overview_markdown(
         self,
         single_processor: LogProcessor,
         snapshot_md: SnapshotAssertion,
     ):
-        '''
+        """
         Test overview markdown output without scenario lines.
-        '''
+        """
         overview = single_processor.get_overview(include_scenario=False)
         md_content = overview.to_markdown()
         normalized = normalize_dynamic_content(md_content)
@@ -50,9 +50,9 @@ def test_overview_with_scenario(
         single_processor: LogProcessor,
         snapshot_md: SnapshotAssertion,
     ):
-        '''
+        """
         Test overview markdown output with scenario lines included.
-        '''
+        """
         overview = single_processor.get_overview(include_scenario=True)
         md_content = overview.to_markdown()
         normalized = normalize_dynamic_content(md_content)
@@ -60,18 +60,18 @@ def test_overview_with_scenario(
 
 
 class TestLinesSnapshots:
-    '''
+    """
     Snapshot tests for line extraction methods.
-    '''
+    """
 
     def test_all_lines(
         self,
         single_processor: LogProcessor,
         snapshot_md: SnapshotAssertion,
     ):
-        '''
+        """
         Test all lines markdown output.
-        '''
+        """
         result = single_processor.get_lines(max_content_length=200)
         md_content = result.to_markdown()
         normalized = normalize_dynamic_content(md_content)
@@ -82,9 +82,9 @@ def test_scenario_lines(
         single_processor: LogProcessor,
         snapshot_md: SnapshotAssertion,
     ):
-        '''
+        """
         Test scenario lines markdown output.
-        '''
+        """
         result = single_processor.get_scenario_lines(max_content_length=200)
         md_content = result.to_markdown()
         normalized = normalize_dynamic_content(md_content)
@@ -95,9 +95,9 @@ def test_line_range(
         single_processor: LogProcessor,
         snapshot_md: SnapshotAssertion,
     ):
-        '''
+        """
         Test line range extraction markdown output.
-        '''
+        """
         result = single_processor.get_lines(start_line=1, end_line=5, max_content_length=200)
         md_content = result.to_markdown()
         normalized = normalize_dynamic_content(md_content)
@@ -105,18 +105,18 @@ def test_line_range(
 
 
 class TestFilteredLinesSnapshots:
-    '''
+    """
     Snapshot tests for filtered line extraction.
-    '''
+    """
 
     def test_filter_by_error_level(
         self,
         single_processor: LogProcessor,
         snapshot_md: SnapshotAssertion,
     ):
-        '''
+        """
         Test filtering by ERROR level.
-        '''
+        """
         result = single_processor.get_lines(levels=['ERROR'], max_content_length=200)
         md_content = result.to_markdown()
         normalized = normalize_dynamic_content(md_content)
@@ -127,9 +127,9 @@ def test_filter_by_warn_level(
         single_processor: LogProcessor,
         snapshot_md: SnapshotAssertion,
     ):
-        '''
+        """
         Test filtering by WARN level.
-        '''
+        """
         result = single_processor.get_lines(levels=['WARN'], max_content_length=200)
         md_content = result.to_markdown()
         normalized = normalize_dynamic_content(md_content)
@@ -140,9 +140,9 @@ def test_filter_by_info_level(
         single_processor: LogProcessor,
         snapshot_md: SnapshotAssertion,
     ):
-        '''
+        """
         Test filtering by INFO level.
-        '''
+        """
         result = single_processor.get_lines(levels=['INFO'], max_content_length=200)
         md_content = result.to_markdown()
         normalized = normalize_dynamic_content(md_content)
@@ -153,9 +153,9 @@ def test_filter_by_multiple_levels(
         single_processor: LogProcessor,
         snapshot_md: SnapshotAssertion,
     ):
-        '''
+        """
         Test filtering by multiple levels (ERROR and WARN).
-        '''
+        """
         result = single_processor.get_lines(levels=['ERROR', 'WARN'], max_content_length=200)
         md_content = result.to_markdown()
         normalized = normalize_dynamic_content(md_content)
@@ -163,18 +163,18 @@ def test_filter_by_multiple_levels(
 
 
 class TestLogLineSnapshots:
-    '''
+    """
     Snapshot tests for individual LogLine formatting.
-    '''
+    """
 
     def test_lines_table_format(
         self,
         single_processor: LogProcessor,
         snapshot_md: SnapshotAssertion,
     ):
-        '''
+        """
         Test table row format for first 5 lines.
-        '''
+        """
         lines = single_processor.flat_lines[:5]
         header = '| Line | Depth | Level | Entity:User | Time | Content |'
         separator = '|------|-------|-------|-------------|------|---------|'
@@ -185,18 +185,18 @@ def test_lines_table_format(
 
 
 class TestMultipleTablesSnapshots:
-    '''
+    """
     Snapshot tests for multiple te-log-table blocks.
-    '''
+    """
 
     def test_all_lines_separate_tables(
         self,
         single_processor: LogProcessor,
         snapshot_md: SnapshotAssertion,
     ):
-        '''
+        """
         Test that all lines render as separate tables.
-        '''
+        """
         result = single_processor.get_lines(max_content_length=200)
         md_content = result.to_markdown()
         normalized = normalize_dynamic_content(md_content)
@@ -206,9 +206,9 @@ def test_line_has_table_index(
         self,
         single_processor: LogProcessor,
     ):
-        '''
+        """
         Test that LogLine objects have correct table_index values.
-        '''
+        """
         lines = single_processor.flat_lines
         expected_lines: int = 12
 
diff --git a/bublik/mcp/tools.py b/bublik/mcp/tools.py
index fe56d9f9e..0bce78702 100644
--- a/bublik/mcp/tools.py
+++ b/bublik/mcp/tools.py
@@ -31,12 +31,12 @@
 
 
 def get_default_date_range():
-    '''
+    """
     Calculate default date range: 6 months ago to today.
 
     Returns:
         Tuple of (from_date, to_date) as ISO format strings (yyyy-mm-dd)
-    '''
+    """
     to_date = date.today()
 
     from_date = to_date - timedelta(days=180)
@@ -44,13 +44,13 @@ def get_default_date_range():
 
 
 def register_tools(mcp: FastMCP):  # noqa: C901
-    '''
+    """
     Register all MCP tools with the FastMCP server.
-    '''
+    """
 
     @mcp.tool()
     async def get_run_details(run_id: int) -> dict:
-        '''
+        """
         Get detailed information about a test run.
 
         Args:
@@ -58,12 +58,12 @@ async def get_run_details(run_id: int) -> dict:
 
         Returns:
             Dictionary with full run details including metadata, stats, etc.
-        '''
+        """
         return await sync_to_async(RunService.get_run_details)(run_id)
 
     @mcp.tool()
     async def get_run_status(run_id: int) -> str:
-        '''
+        """
         Get the status of a test run.
 
         Args:
@@ -71,7 +71,7 @@ async def get_run_status(run_id: int) -> str:
 
         Returns:
             Status string for the run (e.g., 'passed', 'failed', 'skipped')
-        '''
+        """
         return await sync_to_async(RunService.get_run_status)(run_id)
 
     @mcp.tool()
@@ -79,7 +79,7 @@ async def get_run_stats(
         run_id: int,
         requirements: str | None = None,
     ) -> dict:
-        '''
+        """
         Get statistics for a test run.
 
         Args:
@@ -88,12 +88,12 @@ async def get_run_stats(
 
         Returns:
             Dictionary with run statistics including pass/fail counts
-        '''
+        """
         return await sync_to_async(RunService.get_run_stats)(run_id, requirements)
 
     @mcp.tool()
     async def get_run_source(run_id: int) -> str:
-        '''
+        """
         Get the source URL for a test run.
 
         Args:
@@ -101,12 +101,12 @@ async def get_run_source(run_id: int) -> str:
 
         Returns:
             Source URL string
-        '''
+        """
         return await sync_to_async(RunService.get_run_source)(run_id)
 
     @mcp.tool()
     async def get_run_compromised(run_id: int) -> dict:
-        '''
+        """
         Get the compromised status of a test run.
 
         Args:
@@ -114,12 +114,12 @@ async def get_run_compromised(run_id: int) -> dict:
 
         Returns:
             Dictionary with compromised status data including comment and bug ID
-        '''
+        """
         return await sync_to_async(RunService.get_run_compromised)(run_id)
 
     @mcp.tool()
     async def get_result_details(result_id: int) -> dict:
-        '''
+        """
         Get detailed information about a test result.
 
         Args:
@@ -127,12 +127,12 @@ async def get_result_details(result_id: int) -> dict:
 
         Returns:
             Dictionary with full result details
-        '''
+        """
         return await sync_to_async(ResultService.get_result_details)(result_id)
 
     @mcp.tool()
     async def get_result_artifacts_and_verdicts(result_id: int) -> dict:
-        '''
+        """
         Get artifacts and verdicts for a test result.
 
         Args:
@@ -140,7 +140,7 @@ async def get_result_artifacts_and_verdicts(result_id: int) -> dict:
 
         Returns:
             Dictionary with artifacts and verdicts lists
-        '''
+        """
         return await sync_to_async(ResultService.get_result_artifacts_and_verdicts)(result_id)
 
     @mcp.tool()
@@ -154,7 +154,7 @@ async def list_results(
         page: int | None = None,
         page_size: int | None = None,
     ) -> dict:
-        '''
+        """
         List test results with filtering.
 
         Args:
@@ -173,7 +173,7 @@ async def list_results(
 
         Returns:
             Dictionary with pagination metadata and result details
-        '''
+        """
         return await sync_to_async(ResultService.list_results_paginated)(
             parent_id=parent_id,
             test_name=test_name,
@@ -189,17 +189,17 @@ async def list_results(
 
     @mcp.tool()
     async def list_projects() -> list[dict]:
-        '''
+        """
         List all available projects.
 
         Returns:
             List of projects with id and name
-        '''
+        """
         return await sync_to_async(ProjectService.list_projects)()
 
     @mcp.tool()
     async def get_project(project_id: int) -> dict:
-        '''
+        """
         Get details of a specific project.
 
         Args:
@@ -207,7 +207,7 @@ async def get_project(project_id: int) -> dict:
 
         Returns:
             Dictionary with project id and name
-        '''
+        """
         return await sync_to_async(ProjectService.get_project)(project_id)
 
     # Runs tools
@@ -226,7 +226,7 @@ async def list_runs(  # noqa: PLR0913
         page: int | None = None,
         page_size: int | None = None,
     ) -> dict:
-        '''
+        """
         List test runs with comprehensive filtering.
 
         Args:
@@ -244,7 +244,7 @@ async def list_runs(  # noqa: PLR0913
 
         Returns:
             Dictionary with pagination metadata and run details
-        '''
+        """
         queryset = await sync_to_async(RunService.list_runs_queryset)(
             start_date=start_date,
             finish_date=finish_date,
@@ -269,7 +269,7 @@ async def list_runs_today(
         page: int | None = None,
         page_size: int | None = None,
     ) -> dict:
-        '''
+        """
         List test runs for today.
 
         Args:
@@ -279,7 +279,7 @@ async def list_runs_today(
 
         Returns:
             Dictionary with pagination metadata and today's run details
-        '''
+        """
         date_str = await sync_to_async(DashboardService.get_latest_dashboard_date)(
             project_id=project_id,
         )
@@ -300,7 +300,7 @@ async def list_runs_today(
 
     @mcp.tool()
     async def get_latest_run_date(project_id: int | None = None) -> str | None:
-        '''
+        """
         Get the most recent run date.
 
         Args:
@@ -308,7 +308,7 @@ async def get_latest_run_date(project_id: int | None = None) -> str | None:
 
         Returns:
             Date string in yyyy-mm-dd format, or None if no runs exist
-        '''
+        """
 
         def _get_latest_date():
             runs = get_test_runs(order_by='-start')
@@ -328,7 +328,7 @@ async def get_dashboard(
         sort_by: str | None = None,
         validate: bool = False,
     ) -> dict:
-        '''
+        """
         Get dashboard data for a specific date (structured format).
 
         Returns the same format as /api/v2/dashboard/ endpoint with:
@@ -349,7 +349,7 @@ async def get_dashboard(
 
         Raises:
             ValidationError: if validate=True and settings are invalid
-        '''
+        """
         # Optional validation (useful for debugging config issues)
         if validate:
             await sync_to_async(DashboardService.validate_dashboard_settings)(
@@ -369,7 +369,7 @@ async def get_dashboard_today(
         project_id: int | None = None,
         sort_by: str | None = None,
     ) -> dict:
-        '''
+        """
         Get dashboard data for today (structured format).
 
         Args:
@@ -378,7 +378,7 @@ async def get_dashboard_today(
 
         Returns:
             Dictionary with the latest dashboard structure
-        '''
+        """
         date_str = await sync_to_async(DashboardService.get_latest_dashboard_date)(
             project_id=project_id,
         )
@@ -395,7 +395,7 @@ async def get_dashboard_today(
 
     @mcp.tool()
     async def get_latest_dashboard_date(project_id: int | None = None) -> str | None:
-        '''
+        """
         Get the most recent date with dashboard data.
 
         Args:
@@ -403,7 +403,7 @@ async def get_latest_dashboard_date(project_id: int | None = None) -> str | None
 
         Returns:
             Date string in yyyy-mm-dd format, or None if no data
-        '''
+        """
         return await sync_to_async(DashboardService.get_latest_dashboard_date)(
             project_id=project_id,
         )
@@ -412,7 +412,7 @@ async def get_latest_dashboard_date(project_id: int | None = None) -> str | None
 
     @mcp.tool()
     async def get_log_urls(result_id: int, page: int | None = None) -> dict:
-        '''
+        """
         Get log URLs for a test result (without fetching content).
 
         Args:
@@ -421,7 +421,7 @@ async def get_log_urls(result_id: int, page: int | None = None) -> dict:
 
         Returns:
             Dictionary with 'url' and 'attachments_url' keys
-        '''
+        """
         return await sync_to_async(LogService.get_json_log_urls)(
             result_id,
             page,
@@ -430,7 +430,7 @@ async def get_log_urls(result_id: int, page: int | None = None) -> dict:
 
     @mcp.tool()
     async def get_log_html_url(result_id: int) -> str | None:
-        '''
+        """
         Get HTML log URL for a test result.
 
         Args:
@@ -438,7 +438,7 @@ async def get_log_html_url(result_id: int) -> str | None:
 
         Returns:
             URL string or None if not available
-        '''
+        """
         return await sync_to_async(LogService.get_html_log_url)(result_id)
 
     LOG_RETURN_FORMAT: str = 'markdown'  # noqa: N806
@@ -450,7 +450,7 @@ async def get_log_overview(
         include_scenario: bool = True,
         max_content_length: int | None = 200,
     ) -> dict | str:
-        '''
+        """
         Get structured log overview with metadata and optional scenario logs.
 
         Extracts comprehensive log header information including test metadata,
@@ -469,7 +469,7 @@ async def get_log_overview(
 
         Raises:
             ValueError: If no header block is found in the log
-        '''
+        """
 
         def _get_overview():
             log_data = LogService.get_log_json(result_id, page)
@@ -500,7 +500,7 @@ async def get_log_lines(  # noqa: PLR0913
         table_index: int = 0,
         max_content_length: int | None = 200,
     ) -> dict | str:
-        '''
+        """
         Extract and filter log lines.
 
         Retrieves log lines with optional range-based and content-based filtering.
@@ -523,7 +523,7 @@ async def get_log_lines(  # noqa: PLR0913
         Returns:
             LogLinesResult as dictionary or markdown string. When truncated,
             lines will have content_truncated=True and original_content_length set.
-        '''
+        """
 
         def _get_lines():
             log_data = LogService.get_log_json(result_id, page)
@@ -553,7 +553,7 @@ async def get_log_line(
         line_number: int,
         page: int | None = None,
     ) -> dict | str:
-        '''
+        """
         Get a single log line with full, untruncated content.
 
         Use this tool to retrieve the complete content of a specific line
@@ -569,7 +569,7 @@ async def get_log_line(
 
         Raises:
             ValueError: If line_number is not found
-        '''
+        """
 
         def _get_line():
             log_data = LogService.get_log_json(result_id, page)
@@ -600,7 +600,7 @@ def _get_line():
 
     @mcp.tool()
     async def get_tree_path(result_id: int) -> list[int]:
-        '''
+        """
         Get path to a specific test result in the tree.
 
         Args:
@@ -608,7 +608,7 @@ async def get_tree_path(result_id: int) -> list[int]:
 
         Returns:
             List of node IDs from root to the specified result
-        '''
+        """
         return await sync_to_async(TreeService.get_tree_path)(result_id)
 
     # History tools
@@ -626,7 +626,7 @@ async def get_history(  # noqa: PLR0913
         page: int | None = None,
         page_size: int | None = None,
     ) -> dict:
-        '''
+        """
         Get test history (linear format).
 
         Args:
@@ -643,7 +643,7 @@ async def get_history(  # noqa: PLR0913
 
         Returns:
             Dictionary with history results, counts, date range, and pagination
-        '''
+        """
         # Set default date range if not provided
         if from_date is None and to_date is None:
             from_date, to_date = get_default_date_range()
@@ -674,7 +674,7 @@ async def get_history_grouped(  # noqa: PLR0913
         page: int | None = None,
         page_size: int | None = None,
     ) -> dict:
-        '''
+        """
         Get test history grouped by iteration.
 
         Args:
@@ -691,7 +691,7 @@ async def get_history_grouped(  # noqa: PLR0913
 
         Returns:
             Dictionary with grouped history results, counts, date range, and pagination
-        '''
+        """
         # Set default date range if not provided
         if from_date is None and to_date is None:
             from_date, to_date = get_default_date_range()
@@ -713,7 +713,7 @@ async def get_history_grouped(  # noqa: PLR0913
 
     @mcp.tool()
     async def get_run_requirements(run_id: int) -> list[str]:
-        '''
+        """
         Get requirements for a run.
 
         Args:
@@ -721,12 +721,12 @@ async def get_run_requirements(run_id: int) -> list[str]:
 
         Returns:
             Sorted list of requirement strings
-        '''
+        """
         return await sync_to_async(RunService.get_run_requirements)(run_id)
 
     @mcp.tool()
     async def get_run_comment(run_id: int) -> str | None:
-        '''
+        """
         Get comment for a run.
 
         Args:
@@ -734,17 +734,17 @@ async def get_run_comment(run_id: int) -> str | None:
 
         Returns:
             Comment string or None if no comment exists
-        '''
+        """
         return await sync_to_async(RunService.get_run_comment)(run_id)
 
     # Server tools
 
     @mcp.tool()
     async def get_server_version() -> dict:
-        '''
+        """
         Get server version information.
 
         Returns:
             Dictionary with repository revision information
-        '''
+        """
         return await sync_to_async(ServerService.get_version)()
diff --git a/bublik/tests/test_filter_tags.py b/bublik/tests/test_filter_tags.py
index 28fa5be63..2d3a7aac3 100644
--- a/bublik/tests/test_filter_tags.py
+++ b/bublik/tests/test_filter_tags.py
@@ -17,7 +17,7 @@
 logger = get_task_or_server_logger()
 
 
-class TestMeta(object):
+class TestMeta:
     def __init__(self, name, value=None, obj=None):
         self.name = str(name)
         self.value = str(value)
@@ -26,8 +26,7 @@ def __init__(self, name, value=None, obj=None):
     def __str__(self):
         if self.value:
             return f'{self.name}={self.value}'
-        else:
-            return self.name
+        return self.name
 
     def __repr__(self):
         return str(self)
diff --git a/bublik/tests/test_hash_system.py b/bublik/tests/test_hash_system.py
index b5183c466..d08b92b18 100644
--- a/bublik/tests/test_hash_system.py
+++ b/bublik/tests/test_hash_system.py
@@ -4,7 +4,6 @@
 import logging
 from pprint import pformat
 
-from deepdiff import DeepHash
 from django.test import TestCase
 
 from bublik.core.hash_system import HashedModelSerializer
@@ -12,9 +11,7 @@
 from bublik.data import models
 from bublik.data.serializers import (
     ExpectationSerializer,
-    ExpectMetaReadSerializer,
     MetaSerializer,
-    ReferenceSerializer,
 )
 from bublik.tests.fake_generator import gen_expectation_data, gen_meta_data
 
@@ -33,7 +30,7 @@ def test_generate_hash(self):
         in case of list - for any iterable.
         """
 
-        logger.info('TEST: Compare hashes of 3 the same dicts ' 'with unordered elements')
+        logger.info('TEST: Compare hashes of 3 the same dicts with unordered elements')
 
         d1 = {1: 3, 0: {0: 0, 1: [0, 1, 2]}}
         d2 = {1: 3, 0: {1: [0, 1, 2], 0: 0}}
diff --git a/bublik/tests/test_milog_processing.py b/bublik/tests/test_milog_processing.py
index ebb31f307..45901e384 100644
--- a/bublik/tests/test_milog_processing.py
+++ b/bublik/tests/test_milog_processing.py
@@ -8,8 +8,6 @@
     ChartView,
     Measurement,
     MeasurementResult,
-    Meta,
-    TestIterationResult,
 )
 from bublik.tests.fake_generator import gen_test_iteration_result_simple
 
@@ -204,7 +202,7 @@ def check_number_created_objects(view_name, number):
             self.assertEqual(
                 cv.count(),
                 number,
-                'Invalid number of objects created for the view ' f"named {view_name}'",
+                f"Invalid number of objects created for the view named {view_name}'",
             )
 
         check_number_created_objects('graph1', 3)
@@ -218,7 +216,7 @@ def check_measurement_in_chart_view_x_or_y(view_name, measurement_x, measurement
             self.assertEqual(
                 cvx.count(),
                 1,
-                'More than one ChartView with ' f"type 'X' was created for {view_name}",
+                f"More than one ChartView with type 'X' was created for {view_name}",
             )
             if measurement_x:
                 self.assertEqual(
diff --git a/bublik/wsgi.py b/bublik/wsgi.py
index 3641bab8d..cd1f27b36 100644
--- a/bublik/wsgi.py
+++ b/bublik/wsgi.py
@@ -1,13 +1,13 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (C) 2016-2023 OKTET Labs Ltd. All rights reserved.
-'''
+"""
 WSGI config for bublik project.
 
 It exposes the WSGI callable as a module-level variable named ``application``.
 
 For more information on this file, see
 https://docs.djangoproject.com/en/1.11/howto/deployment/wsgi/
-'''
+"""
 
 import os
 
diff --git a/pyproject.toml b/pyproject.toml
index 6e9ff08dd..a3d461d42 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,12 @@
 [tool.ruff]
 line-length = 96
 target-version = 'py38'
+# Excluded from both the linter and the formatter: Django migrations are
+# historical artifacts and reformatting them adds noise while hurting
+# `git blame`. force-exclude keeps them excluded even when passed explicitly
+# (e.g. by the pre-commit hook).
+force-exclude = true
+extend-exclude = ['migrations']
 
 [tool.ruff.lint]
 select = [
@@ -80,6 +86,11 @@ select = [
 ignore = [
     # overwriting some variables (seems to be usefull in some cases)
     'PLW2901',
+    # Ruff formatter handles trailing commas.
+    'COM812',
+    # Ruff formatter handles multiline string and docstring quotes.
+    'Q001',
+    'Q002',
 ]
 exclude = [
     '.env',
@@ -138,8 +149,8 @@ exclude = [
 [tool.ruff.lint.flake8-quotes]
 avoid-escape = false
 inline-quotes = 'single'
-docstring-quotes = 'single'
-multiline-quotes = 'single'
+docstring-quotes = 'double'
+multiline-quotes = 'double'
 
 [tool.ruff.lint.mccabe]
 max-complexity = 16
@@ -155,7 +166,5 @@ max-branches = 30
 max-statements = 100
 max-returns = 7
 
-[tool.black]
-line-length = 96
-target-version = ['py38']
-skip-string-normalization = true
+[tool.ruff.format]
+quote-style = 'single'
diff --git a/requirements.txt b/requirements.txt
index e12a91e12..82c06a83c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,11 +7,9 @@ asn1crypto==0.24.0
 astor==0.8.1
 attrs==23.1.0
 autoflake==1.4
-autopep8==1.4.3
 Babel==2.16.0
 beautifulsoup4==4.7.1
 billiard==4.2.2
-black==26.3.1
 celery==5.5.3
 certifi==2024.8.30
 cffi==2.0.0
@@ -36,9 +34,7 @@ djangorestframework==3.15.2
 drf-spectacular-sidecar==2024.11.1
 drf-spectacular==0.27.2
 fastmcp==3.2.0
-flake8==3.9.2
 flower==2.0.1
-flynt==0.64
 future==1.0.0
 gitdb==4.0.2
 GitPython==3.1.50
@@ -48,11 +44,9 @@ httplib2==0.22.0
 idna==3.10
 importlab==0.8.1
 importlib-metadata==8.7.1
-isort==5.8.0
 jsonschema==4.26.0
 kombu==5.5.4
 Markdown==3.9
-mccabe==0.6.1
 more-itertools==8.1.0
 networkx
 ninja==1.10.2.3
@@ -60,19 +54,15 @@ ordered-set
 packaging==24.1
 pendulum==3.0.0
 pep517==0.12.0
-pep8==1.7.1
 pip-review==1.0
 pip-tools
 pipdeptree==2.2.1
 pre-commit==3.3.2
 psycopg2-binary==2.9.10
 py-key-value-aio[disk]==0.4.4
-pycodestyle==2.7.0
 pycparser==2.19
 pydot==2.0.0
-pyflakes==2.3.1
 pykerberos==1.2.4
-pylint==3.3.8
 pyparsing==3.1.2
 pytest==9.0.3
 python-dateutil==2.9.0
@@ -98,11 +88,9 @@ toml==0.10.2
 tomli
 tornado==6.5.5
 treelib==1.6.1
-unify==0.5
 urllib3==2.7.0
 uvicorn[standard]
 vine==5.1.0
 xlwt==1.3.0
 yamale==5.2.1
-yapf==0.31.0
 zipp==3.20.2
diff --git a/scripts/generate_secret_key.py b/scripts/generate_secret_key.py
index 85a08c3a6..a5d3e0aba 100755
--- a/scripts/generate_secret_key.py
+++ b/scripts/generate_secret_key.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (C) 2016-2023 OKTET Labs Ltd. All rights reserved.
-'''
+"""
 This script generates a secret key for Django application.
 
 The Django secret key is used to provide cryptographic signing and makes use of this in various
@@ -14,7 +14,7 @@
 
 To revoke the key, a new secret needs to be generated. All sessions or cookies signed with the
 key will be invalided.
-'''
+"""
 
 import argparse
 import logging
diff --git a/scripts/import_logs_converter.py b/scripts/import_logs_converter.py
index 4cb780457..fbea2162d 100755
--- a/scripts/import_logs_converter.py
+++ b/scripts/import_logs_converter.py
@@ -2,10 +2,10 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (C) 2016-2023 OKTET Labs Ltd. All rights reserved.
 
-'''
+"""
 This script brings all import logs to a format close to JSON.
 Logs of the new format are saved in file with the name '{task_id}' (without '.log' extension).
-'''
+"""
 
 import argparse
 import json
@@ -20,9 +20,9 @@
 
 
 def get_logdirs(av):
-    '''
+    """
     Get a list of files/directories with logs from command line arguments.
-    '''
+    """
 
     parser = argparse.ArgumentParser(
         description='Reformat the import logs from the specified directories '
@@ -37,10 +37,10 @@ def get_logdirs(av):
 
 
 def is_new_format_line(line):
-    '''
+    """
     Check if the passed log line has a new format
     (JSON with the keys 'asctime', 'levelname', 'module', 'message').
-    '''
+    """
 
     try:
         json_line = json.loads(line)
@@ -50,7 +50,7 @@ def is_new_format_line(line):
 
 
 def log_line_parser(line):
-    '''
+    """
     Returns a new format log line corresponding to the passed line.
     Parameter @line is a string that will be converted.
 
@@ -66,7 +66,7 @@ def log_line_parser(line):
 
     Note: For a line that has an output format, the line is returned unchanged.
           For a line corresponding to the line break character, None is returned.
-    '''
+    """
 
     if is_new_format_line(line):
         return line
@@ -91,9 +91,11 @@ def log_line_parser(line):
         + message
     )
     log_line = log_line.setParseAction(
-        lambda t: f'{{"asctime": {json.dumps(t.asctime)}, '
-        f'"levelname": {json.dumps(t.levelname)}, "module": {json.dumps(t.module)}, '
-        f'"message": {json.dumps(t.message)}}}',
+        lambda t: (
+            f'{{"asctime": {json.dumps(t.asctime)}, '
+            f'"levelname": {json.dumps(t.levelname)}, "module": {json.dumps(t.module)}, '
+            f'"message": {json.dumps(t.message)}}}'
+        ),
     )
 
     try:
@@ -106,10 +108,10 @@ def log_line_parser(line):
 
 
 def log_file_converter(logpath):
-    '''
+    """
     Convert logs from the passed file into logs of a new format.
     Write the result to a file with the same name, but without extension.
-    '''
+    """
 
     # check if the log is empty
     if os.path.getsize(logpath) == 0:
@@ -156,9 +158,7 @@ def main(av):
 
     except pp.ParseException as pe:
         logging.error(
-            f'Strange log file "{logpath}"!\n'
-            f'Error message: {pe}\n'
-            f'The line: "{pe.line}"',
+            f'Strange log file "{logpath}"!\nError message: {pe}\nThe line: "{pe.line}"',
         )
         return 1
 
diff --git a/scripts/pyanalyze b/scripts/pyanalyze
index fb9603769..a9604e3e6 100755
--- a/scripts/pyanalyze
+++ b/scripts/pyanalyze
@@ -11,11 +11,9 @@ status=0
 pip show -q pytype && pytype $@
 status=$(( $status | $? ))
 
-# Flake8 checks Python code compliance to PEP8, McCabe complexity and english grammar.
-# Displays the warnings in a per-file, merged output.
-# https://flake8.pycqa.org/en/latest/index.html.
+# Ruff checks Python code style, imports, complexity, and common lint issues.
 #
-pip show -q flake8 && flake8 $@
+pip show -q ruff && ruff check $@
 status=$(( $status | $? ))
 
 # Pyanalize status.
diff --git a/scripts/pyformat b/scripts/pyformat
index 3c2c66622..49653486e 100755
--- a/scripts/pyformat
+++ b/scripts/pyformat
@@ -2,11 +2,7 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (C) 2016-2023 OKTET Labs Ltd. All rights reserved.
 
-do_black=true
-do_flynt=true
-do_unify=true
-do_ruff=true
-ruff_fix="--fix"
+do_check=false
 do_verbose=false
 
 # Files to be fixed
@@ -27,11 +23,7 @@ $0 <file>
 
 Options:
 
- -n : switch to 'enable' mode - only enabled things will be done
- -b : do only black
- -f : do f-strings
- -s : unify strings
- -r : run ruff
+ -v : verbose mode
  -c : check-only!
 EOF
 }
@@ -46,30 +38,8 @@ while [ -n "$1" ] ; do
     -v)
       do_verbose=true
       ;;
-    -n)
-      do_black=false
-      do_flynt=false
-      do_unify=false
-      do_ruff=false
-      ;;
     -c)
       do_check=true
-      black_options="--check"
-      flynt_options="-f"
-      unify_options="-c"
-      ruff_fix=""
-      ;;
-    -b)
-      do_black=true
-      ;;
-    -f)
-      do_flynt=true
-      ;;
-    -s)
-      do_unify=true
-      ;;
-    -r)
-      do_ruff=true
       ;;
     -h|--help)
       help
@@ -89,52 +59,34 @@ while [ -n "$1" ] ; do
   shift
 done
 
-if $do_unify; then
-  # Unifies strings
-  #
-  echo "Running unify"
-  which unify 2>&1 >/dev/null && try unify $unify_options -r --quote \' $FILES
-  unify_status=$?
-  [ $unify_status -eq 0 ] || echo "Unify failed"
-  status=$(( $status || $unify_status ))
-fi
-
-if $do_flynt; then
-  # Converts a code from old "%-formatted" and .format(...) strings into "f-strings".
-  # https://github.com/ikamensh/flynt.
-  #
-  which flynt 2>&1 >/dev/null && try flynt $flynt_options -q $FILES
-  flynt_status=$?
-  [ $flynt_status -eq 0 ] || echo "Flynt failed"
-  status=$(( $status || $flynt_status ))
+if ! which ruff >/dev/null 2>&1; then
+  echo "The ruff executable is not available"
+  exit 1
 fi
 
-if $do_black; then
-  # Format Python code. Makes changes to files in place.
-  # https://github.com/psf/black.
-  #
-  echo "Running black"
-  which black 2>&1 >/dev/null && \
-    try black $black_options --skip-string-normalization $FILES
-  black_status=$?
-  [ $black_status -eq 0 ] || echo "Black failed"
-  status=$(( $status || $black_status ))
+if $do_check; then
+  echo "Running ruff format check"
+  try ruff format --check --diff $FILES
+  format_status=$?
+else
+  echo "Running ruff format"
+  try ruff format $FILES
+  format_status=$?
 fi
+[ $format_status -eq 0 ] || echo "Ruff format failed"
+status=$(( status || format_status ))
 
-if $do_ruff; then
-  # Run ruff - .
-  # https://github.com/charliermarsh/ruff
-  #
-  if python -c "import ruff"; then
-    echo "Running ruff"
-    which ruff 2>&1 >/dev/null && try ruff check $FILES $ruff_fix
-    ruff_status=$?
-    [ $ruff_status -eq 0 ] || echo "Ruff failed"
-    status=$(( $status || $ruff_status ))
-  else
-    echo "The ruff is not installed"
-  fi
+if $do_check; then
+  echo "Running ruff check"
+  try ruff check $FILES
+  ruff_status=$?
+else
+  echo "Running ruff check with fixes"
+  try ruff check --fix $FILES
+  ruff_status=$?
 fi
+[ $ruff_status -eq 0 ] || echo "Ruff check failed"
+status=$(( status || ruff_status ))
 
 # Pyformat status.
 #