Add trailing newline when dumping JSON to files

examples/inference/gpt/gpt_dynamic_inference.py

@@ -435,6 +435,7 @@ def escape_str(s):
             print(f' Saving results to {args.output_path}')
             with open(args.output_path, "w") as fp:
                 json.dump(json_results, fp, indent=1)
+                fp.write("\n")  # End file in newline
 
         # Timing results.
         stats = torch.cuda.memory_stats()

examples/inference/gpt/gpt_dynamic_inference_with_coordinator.py

@@ -154,6 +154,7 @@ async def main(
                 json_results = throughput_dict
             with open(args.output_path, "w") as fp:
                 json.dump(json_results, fp, indent=4)
+                fp.write("\n")  # End file in newline
         else:
             print("Results:")
             unique_prompt_map = defaultdict(list)

examples/inference/gpt/gpt_static_inference.py

@@ -188,6 +188,7 @@ def main():
 
         with open(args.output_path, 'w') as f:
             json.dump(results_output, f)
+            f.write('\n')  # End file in newline
 
     # Print unique prompts + outputs.
     if torch.distributed.get_rank() == 0:

examples/multimodal/evaluation/evaluate_ai2d.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 
@@ -31,6 +33,7 @@ def merge_input_files(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file, indent=4, sort_keys=True)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_chartqa.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 
@@ -28,6 +30,7 @@ def merge_input_files(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file, indent=4, sort_keys=True)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_coco.py

@@ -33,6 +33,7 @@ def convert_to_coco_format(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file, indent=4, sort_keys=True)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_infovqa.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 
@@ -28,6 +30,7 @@ def merge_input_files(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_mathvista.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 import re
@@ -29,6 +31,7 @@ def merge_input_files(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file, indent=4, sort_keys=True)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_mmmu.py

@@ -80,6 +80,7 @@ def convert_to_mmmu_format(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(output, output_file, indent=4, sort_keys=True)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_ocrbench.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 
@@ -26,6 +28,7 @@ def merge_input_files(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file, indent=4, sort_keys=True)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_ocrbench_v2.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 import subprocess
@@ -30,6 +32,7 @@ def convert_to_ocrbench_v2_format(input_path, groundtruth_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(output, output_file)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_rd_tablebench.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import glob
 import json
@@ -35,6 +37,7 @@ def convert_to_rdtablebench_format(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(output, output_file)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_realworldqa.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 
@@ -25,6 +27,7 @@ def merge_input_files(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file, indent=4, sort_keys=True)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_spdocvqa.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 
@@ -28,6 +30,7 @@ def merge_input_files(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_textvqa.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 
@@ -31,6 +33,7 @@ def merge_input_files(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file, indent=4, sort_keys=True)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_video_motionbench.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 
@@ -26,6 +28,7 @@ def merge_input_files(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file, indent=4, sort_keys=True)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_video_mvbench.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 
@@ -25,6 +27,7 @@ def merge_input_files(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file, indent=4, sort_keys=True)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_video_phys_game_bench.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 
@@ -24,6 +26,7 @@ def merge_input_files(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file, indent=4, sort_keys=True)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/evaluate_vqav2.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import argparse
 import json
 from typing import List
@@ -78,6 +80,7 @@ def merge_input_files(input_path):
 
     with open(output_file_path, "w") as output_file:
         json.dump(results, output_file, indent=4, sort_keys=True)
+        output_file.write("\n")  # End file in newline
 
     return output_file_path
 

examples/multimodal/evaluation/mmmu_utils.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 # The following code is adapted from
 # https://github.com/MMMU-Benchmark/MMMU/blob/main/mmmu/utils/data_utils.py,
 # which is licensed under the Apache License 2.0. More details on the license can be
@@ -526,10 +528,11 @@ def mmmu_main_eval(output_dict, task_cfg):
             )
             eval_output_dict[res['question_id']] = pred_ans
 
-    json.dump(eval_output_dict, open("validation_mmmu_iter6000_merged.0.53.sorted.json", "w"), indent=4, sort_keys=True)
-
+    with open("validation_mmmu_iter6000_merged.0.53.sorted.json", "w") as f:
+        json.dump(eval_output_dict, f, indent=4, sort_keys=True)
+        f.write("\n")  # End file in newline
 
     x = mmmu_main_eval(eval_output_dict,
                    task_cfg=tasks['mmmu'])
 
-    print(x)
+    print(x)

megatron/core/config_logger.py

@@ -121,6 +121,7 @@ def log_config_to_disk(config, dict_data, prefix='', rank_str=''):
     else:
         with open(f'{path}.json', 'w') as fp:
             json.dump(dict_data, fp, cls=JSONEncoderWithMcoreTypes)
+            fp.write('\n')  # End file in newline
 
 
 __all__ = ['has_config_logger_enabled', 'log_config_to_disk']

megatron/core/dist_checkpointing/core.py

@@ -88,6 +88,8 @@ def save_config(config: CheckpointingConfig, checkpoint_dir: str):
         msc = MultiStorageClientFeature.import_package()
         with msc.open(config_path, 'w') as f:
             json.dump(asdict(config), f)
+            f.write('\n')  # End file in newline
     else:
         with open(config_path, 'w') as f:
             json.dump(asdict(config), f)
+            f.write('\n')  # End file in newline

megatron/core/tokenizers/megatron_tokenizer.py

@@ -163,6 +163,7 @@ def write_metadata(
 
             with open(metadata_path, "w") as f:
                 json.dump(metadata, f)
+                f.write("\n")  # End file in newline
 
             logger.info(f"Metadata file was sucessfully saved: {metadata_path}.")
 

megatron/rl/rl_utils.py

@@ -574,6 +574,7 @@ def get_environment_rollouts(
             'w',
         ) as f:
             json.dump([[r.model_dump() for r in group] for group in rollouts], f)
+            f.write('\n')  # End file in newline
 
     return rollouts
 
@@ -1601,6 +1602,7 @@ def evaluate_and_print_results_rl(
                     'w',
                 ) as f:
                     json.dump([[r.model_dump() for r in group] for group in dp_eval_results], f)
+                    f.write('\n')  # End file in newline
 
 
 def calculate_grpo_loss(

megatron/training/ft_integration.py

@@ -238,6 +238,7 @@ def _update_timeouts(selected_sections, calc_out_of_section):
         ft_state = rmon_cli.state_dict()
         with open(_ft_state_path, "w") as f:
             json.dump(ft_state, f)
+            f.write("\n")  # End file in newline
         print_rank_0(f"FT: updated timeouts saved to {_ft_state_path}. {rmon_cli.section_timeouts}")
 
 

tests/functional_tests/python_test_utils/compute_golden_statistics.py

@@ -796,6 +796,7 @@ def main():
 
     with open(output_path, 'w') as f:
         json.dump(output, f, indent=2)
+        f.write('\n')  # End file in newline
 
     logger.info(f"Statistics written to {args.output}")
 

tests/functional_tests/python_test_utils/get_test_results_from_tensorboard_logs.py

@@ -1,3 +1,5 @@
+# Copyright (c) 2023-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
 import os
 
 os.environ["OPENBLAS_NUM_THREADS"] = "1"
@@ -76,6 +78,7 @@ def collect_train_test_metrics(
                 fh,
                 indent=4,
             )
+            fh.write("\n")  # End file in newline
 
 
 if __name__ == "__main__":

tests/functional_tests/test_cases/common/moe_perf/__main__.py

@@ -106,7 +106,7 @@ def _persist_baselines(data: Dict[str, Dict[str, float]]) -> None:
     BASELINES_PATH.parent.mkdir(parents=True, exist_ok=True)
     with BASELINES_PATH.open("w", encoding="utf-8") as fh:
         json.dump(data, fh, indent=2, sort_keys=True)
-        fh.write("\n")
+        fh.write("\n")  # End file in newline
 
 
 def _serialize_metrics(metrics: Dict[str, float]) -> Dict[str, float]:

tools/build_sequences_per_dataset.py

@@ -113,5 +113,6 @@ def build_sequences_per_dataset(args):
 
     with open(args.path_to_sequences_per_dataset_json, "w") as f:
         json.dump(sequence_count_dict, f)
+        f.write("\n")  # End file in newline
 
-    print(f"Done! Saving --path-to-sequences-per-dataset file to {args.path_to_sequences_per_dataset_json}")
+    print(f"Done! Saving --path-to-sequences-per-dataset file to {args.path_to_sequences_per_dataset_json}")

tools/checkpoint/checkpoint_inspector.py

@@ -967,6 +967,7 @@ def print_torch_dcp_in_json(torch_dcp_dir, model_weight_prefix="model.module"):
         json_file_path = os.path.join(torch_dcp_dir, "param_to_param_group_map.json")
         with open(json_file_path, "w") as json_file:
             json.dump(serializable_dict, json_file, indent=2)
+            json_file.write("\n")  # End file in newline
         click.echo(f"Saved converted param_to_param_group_map to: {json_file_path}")
 
 

tools/checkpoint/loader_llama_mistral.py

@@ -70,6 +70,7 @@ def read_json(path):
 def write_json(text, path):
     with open(path, "w") as f:
         json.dump(text, f)
+        f.write("\n")  # End file in newline
 
 
 # This conversion is adapted from