diff --git a/bench.py b/bench.py
index 37f2e7ef..a1e8aa73 100644
--- a/bench.py
+++ b/bench.py
@@ -1,3 +1,4 @@
+"""Performance benchmark for core ChessBoard operations."""
 import sys
 import time
 
@@ -7,12 +8,12 @@
 
 board = ChessBoard(FULL_INIT_FEN)
 
-# Test 1: get_pieces
+# Test 1: get_all_fench_positions
 start = time.perf_counter()
 for _ in range(10000):
-    list(board.get_all_pieces())
+    list(board.get_all_fench_positions())
 elapsed = time.perf_counter() - start
-print(f"get_pieces x10000: {elapsed:.3f}s")
+print(f"get_all_fench_positions x10000: {elapsed:.3f}s")
 
 # Test 2: create_moves
 start = time.perf_counter()
diff --git a/demo/end_game_master.py b/demo/end_game_master.py
index ff728fda..29f615a9 100644
--- a/demo/end_game_master.py
+++ b/demo/end_game_master.py
@@ -15,6 +15,10 @@
 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """
+# pylint: disable=import-error,no-member,not-callable,undefined-variable,wildcard-import
+# pylint: disable=missing-class-docstring,invalid-name,attribute-defined-outside-init
+# pylint: disable=redefined-builtin,anomalous-backslash-in-string,pointless-string-statement
+# pylint: disable=broad-exception-caught
 
 import logging
 import os
@@ -197,14 +201,14 @@ def draw(self):
         for x in range(9):
             for y in range(10):
                 key = (x, y)
-                piece = self.board.get_piece(key)
-                if not piece:
+                fench = self.board.get_fench(key)
+                if not fench or fench == ".":
                     continue
 
-                image = self.pieces_image[piece.fench.lower()]
+                image = self.pieces_image[fench.lower()]
                 board_pos = pos_to_screen(key)
 
-                if piece.color == cchess.SIDE_RED:
+                if fench.isupper():
                     offset = (0, 0, 52, 52)
                 else:
                     offset = (53, 0, 52, 52)
@@ -240,18 +244,18 @@ def show_move(self, p_from, p_to):
 
             for x in range(9):
                 for y in range(10):
-                    key = Pos(x, y)
-                    piece = self.board.get_piece(key)
-                    if piece is None:
+                    key = (x, y)
+                    fench = self.board.get_fench(key)
+                    if fench is None or fench == ".":
                         continue
 
-                    board_pos = pos_to_screen(piece)
-                    image = self.pieces_image[piece.fench.lower()]
-                    offset = (int(piece.side) * 53, 0, 52, 52)
+                    board_pos = pos_to_screen(key)
+                    image = self.pieces_image[fench.lower()]
+                    offset = (0, 0, 52, 52) if fench.isupper() else (53, 0, 52, 52)
                     if key == p_from:
                         self.screen.blit(image, step(), offset)
                     else:
-                        self.screen.blit(image, board_pos(), offset)
+                        self.screen.blit(image, board_pos, offset)
 
             pygame.display.flip()
             pygame.event.pump()
@@ -310,7 +314,7 @@ def __init__(self, file):
         self.flile_eplib = self.file + ".eplib"
 
     def load(self):
-        with open(self.file_src, "r") as f:
+        with open(self.file_src, "r", encoding="utf-8") as f:
             lines = f.readlines()
 
         for line in lines:
@@ -324,7 +328,7 @@ def load(self):
 
         if os.path.isfile(self.file + ".eplib"):
             with open(self.flile_eplib, "rb") as f:
-                done_array = bytearray(open(self.flile_eplib, "rb").read())
+                done_array = bytearray(f.read())
             for i, it in enumerate(done_array):
                 if i >= len(self.games):
                     break
@@ -455,8 +459,8 @@ def next(self, index):
 
     fen_moves.sort(key=lambda x: x[0])
 
-    with open(f"{type_name}.csv", "w") as f:
-        f.write(f"title, old_name, hint, fen, moves\n")
+    with open(f"{type_name}.csv", "w", encoding="utf-8") as f:
+        f.write("title, old_name, hint, fen, moves\n")
         for move_len, old_name, fen, moves in fen_moves:
             steps = (move_len + 1) // 2
             f.write(f"{steps}步杀, {old_name}, {get_title_full(fen)}, {fen}, {moves}\n")
diff --git a/src/cchess/io_xqf.py b/src/cchess/io_xqf.py
index 710d2220..33a3b8de 100644
--- a/src/cchess/io_xqf.py
+++ b/src/cchess/io_xqf.py
@@ -14,7 +14,7 @@
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """
 
-# pylint: disable=too-many-locals,too-many-branches,too-many-statements
+# pylint: disable=too-many-locals,too-many-branches,too-many-statements,invalid-name,too-few-public-methods
 
 import struct
 from typing import Tuple
diff --git a/src/cchess/move.py b/src/cchess/move.py
index 1d0d18f5..e63e5d7c 100644
--- a/src/cchess/move.py
+++ b/src/cchess/move.py
@@ -570,7 +570,6 @@ def make_branchs_tag(self, branch_id, depth):  # pylint: disable=unused-argument
 
         当前为桩实现，预留接口供未来扩展。
         """
-        ...  # 桩实现占位
 
     def get_variations(self, include_me=False):
         """返回当前走子的所有分支（变招），可选择是否包含自身。"""