python-chess v0.23.4

New features:

* XBoard: Support pondering. Thanks Manik Charan.
* UCI: Support unofficial `info ebf`.

Bugfixes:

* Implement 16 bit DTZ mapping, which is required for some of the longest
  7 piece endgames.

python-chess v0.23.3

New features:

* XBoard: Support `variant`. Thanks gbtami.

python-chess v0.23.2

Bugfixes:

* XBoard: Handle multiple features and features with spaces. Thanks gbtami.
* XBoard: Ignore debug output prefixed with `#`. Thanks Dan Ravensloft and
  Manik Charan.

python-chess v0.23.1

Bugfixes:

* Fix DTZ in case of mate in 1. This is a cosmetic fix, as the previous
  behavior was only off by one (which is allowed by design).

python-chess v0.23.0

New features:

* Experimental support for 7 piece Syzygy tablebases.

Changes:

* `chess.syzygy.filenames()` was renamed to `tablenames()` and
  gained an optional `piece_count=6` argument.
* `chess.syzygy.normalize_filename()` was renamed to `normalize_tablename()`.
* The undocumented constructors of `chess.syzygy.WdlTable` and
  `chess.syzygy.DtzTable` have been changed.

python-chess v0.22.2

Bugfixes:

* In standard chess promoted pieces were incorrectly considered as
  distinguishable from normal pieces with regard to position equality
  and threefold repetition. Thanks to kn-sq-tb for reporting.

Changes:

* The PGN `game.headers` are now a custom mutable mapping that validates the
  validity of tag names.
* Basic attack and pin methods moved to `BaseBoard`.
* Documentation fixes and improvements.

New features:

* Added `Board.lan()` for long algebraic notation.

python-chess v0.22.1

New features:

* Added `Board.mirror()`, `SquareSet.mirror()` and `bswap()`.
* Added `chess.pgn.GameNode.accept_subgame()`.
* XBoard: Added `resign`, `analyze`, `exit`, `name`, `rating`, `computer`,
  `egtpath`, `pause`, `resume`. Completed option parsing.

Changes:

* `chess.pgn`: Accept FICS wilds without warning.
* XBoard: Inform engine about game results.

Bugfixes:

* `chess.pgn`: Allow games without movetext.
* XBoard: Fixed draw handling.

python-chess v0.22.0

Changes:

* `len(board.legal_moves)` **replaced by** `board.legal_moves.count()`.
  Previously `list(board.legal_moves)` was generating moves twice, resulting in
  a considerable slowdown. Thanks to Martin C. Doege for reporting.
* XBoard: `offer_draw` renamed to `draw`.

New features:

* XBoard: Added `DrawHandler`.

python-chess v0.21.2

Changes:

* `chess.svg` is now fully SVG Tiny 1.2 compatible.

python-chess v0.21.1

Bugfixes:

* `Board.set_piece_at()` no longer shadows optional `promoted`
  argument from `BaseBoard`.
* Fixed `ThreeCheckBoard.is_irreversible()` and
  `ThreeCheckBoard._transposition_key()`.

New features:

* Added `Game.without_tag_roster()`. `chess.pgn.StringExporter()` can now
  handle games without any headers.
* XBoard: `white`, `black`, `random`, `nps`, `optim`, `undo`, `remove`. Thanks
  to Manik Charan.

Changes:

* Documentation fixes and tweaks by Boštjan Mejak.
* Changed unicode character for empty squares in `Board.unicode()`.