Changelog for python-chess¶
New in v1.9.0¶
Expand position validation to detect check conflicting with en passant square.
chess.svg.board()add ASCII board as description of SVG.
Add hint when engine process dies due to illegal instruction.
New in v1.8.0¶
SquareSet.issubset()by swapping their respective implementations.
Read and write PGN comments like
New in v1.7.0¶
Add new models for
sf(the new default) and
chess.pgn: Fix skipping with nested variations.
chess.svg: Make check gradient compatible with QtSvg.
New in v1.6.1¶
chess.engine.SimpleEngine.play(..., draw_offered=True)available. Previously only added for
New in v1.6.0¶
Allow offering a draw to XBoard engines using
Now detects insufficient material in Horde. Thanks @stevepapazis!
chess.engine.popen_engine(..., setpgrp=True)on Windows now merges
creationflagsinstead of overriding. On Unix it now uses
start_new_sessioninstead of calling
chess.svgproduces SVG Tiny 1.2, and prepare SVG 2 forwards compatibility.
Fix slightly off-center pawns in
Fix typing error in Python 3.10 (due to added
New in v1.5.0¶
Fixed typing of
chess.pgn.Mainline.__reversed__(). It is now a generator, and
chess.pgn.ReverseMainlinehas been removed. This is a breaking change but a required bugfix.
Implement UCI ponderhit for consecutive calls to
chess.engine.Protocol.play(..., ponder=True). Previously, the pondering search was always stopped and restarted.
Provide the full move stack, not just the position, for UCI pondering.
Fixed XBoard level in sudden death games.
Ignore trailing space after ponder move sent by UCI engine. Previously, such a move would be rejected.
Prevent cancelling engine commands after they have already been cancelled or completed. Some internals (
chess.engine.BaseCommand) have been changed to accomplish this.
Implement and accept usermove feature for XBoard engines.
Special thanks to @MarkZH for many of the engine related changes in this release!
New in v1.4.0¶
chess.pgn.GameNode.eval()accept PGN comments like
[%eval 2.5,11], meaning 250 centipawns at depth 11. Use
chess.pgn.GameNode.set_eval(..., depth)to get and set the depth.
Read and write PGN comments with millisecond precision like
Recover from invalid UTF-8 sent by an UCI engine, by ignoring that (and only that) line.
New in v1.3.3¶
Fixed unintended collisions and optimized
chess.STATUS_IMPOSSIBLE_CHECKif checkers are aligned with other king.
chess.STATUS_IMPOSSIBLE_CHECKif checker is aligned with en passant square and king.
Implemented Lichess winning chance model for
New in v1.3.2¶
Added a new reason for
board.status()to be invalid:
chess.STATUS_IMPOSSIBLE_CHECK. This detects positions where two sliding pieces are giving check while also being aligned with the king on the same rank, file, or diagonal. Such positions are impossible to reach, break Stockfish, and maybe other engines.
New in v1.3.1¶
chess.pgn.read_game()now properly detects variant games with Chess960 castling rights (as well as mislabeled Standard Chess960 games). Previously, all castling moves in such games were rejected.
New in v1.3.0¶
chess.pgn.ChildNode, a subclass of
chess.pgn.GameNodefor all nodes other than the root node, and converted
chess.pgn.GameNodeto an abstract base class. This improves ergonomics in typed code.
The change is backwards compatible if using only documented features. However, a notable undocumented feature is the ability to create dangling nodes. This is no longer possible. If you have been using this for subclassing, override
GameNode.dangling_node(). It is now the only method that creates child nodes.
weakref-based caching in
New in v1.2.2¶
Fixed regression where releases were uploaded without the
New in v1.2.1¶
ModuleNotFoundError: No module named 'chess'after upgrading from previous versions? Run
pip install --force-reinstall chess(due to https://github.com/niklasf/python-chess/issues/680).
New in v1.2.0¶
chess.engine.Wdl, and conversions from scores:
chess.engine.Score.score(*, mate_score: int) -> intoverload.
chess.pgn.GameNode.eval()is now always relative to the side to move. The ambiguity around
[%eval #0]has been resolved to
Mate(-0). This makes sense, given that the authors of the specification probably had standard chess in mind (where a game-ending move is always a loss for the opponent). Previously, this would be parsed as
chess.engine.InfoDict["wdl"]as the new
chess.engine.PovWdl, rather than
Tuple[int, int, int]. The new type is backwards compatible, but it is recommended to use its documented fields and methods instead.
chess.engine.PovScore.__str__(). String representation falls back to
chess.Board.epd()is now typed as
Literal["legal", "fen", "xfen"]rather than
New in v1.1.0¶
chess.svg.board(..., orientation). This is a more idiomatic way to set the board orientation than
chess.Board.parse_san(). Now accepts fully specified moves like
e2e4, even if that is not a pawn move, castling notation with zeros, null moves in UCI notation, and null moves in XBoard notation.
New in v1.0.1¶
chess.svg: Restored SVG Tiny compatibility by splitting colors like
#rrggbbaainto a solid color and opacity.
New in v1.0.0¶
CHANGELOG-OLD.rst for changes up to v1.0.0.