Accept a1a1 as UCI null move (used by lc0, closes #1119)

niklasf · Nov 9, 2024 · 518d662 · 518d662
1 parent d625be1
commit 518d662
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/chess/__init__.py b/chess/__init__.py
@@ -705,7 +705,7 @@ def from_uci(cls, uci: str) -> Move:
                 promotion = PIECE_SYMBOLS.index(uci[4]) if len(uci) == 5 else None
             except ValueError:
                 raise InvalidMoveError(f"invalid uci: {uci!r}")
-            if from_square == to_square:
+            if from_square == to_square and from_square != A1:
                 raise InvalidMoveError(f"invalid uci (use 0000 for null moves): {uci!r}")
             return cls(from_square, to_square, promotion=promotion)
         else: