python-chess v0.12.0

* Python 2.6 support. Patch by vdbergh.

* Pure Python Gaviota tablebase probing. Thanks to Jean-Noël Avila.

python-chess v0.11.1

Bugfixes:

* `syzygy.Tablebases.probe_dtz()` has was giving wrong results for some
  positions with possible en passant capturing. This was found and fixed
  upstream: https://github.com/official-stockfish/Stockfish/issues/394.

* Ignore extra spaces in UCI `info` lines, as for example sent by the
  Hakkapeliitta engine. Thanks to Jürgen Précour for reporting

python-chess v0.11.0

Changes:

* **Chess960** support and the **representation of castling moves** has been
  changed.

  The constructor of board has a new `chess960` argument, defaulting to
  `False`: `Board(fen=STARTING_FEN, chess960=False)`. That property is
  available as `Board.chess960`.

  In Chess960 mode the behaviour is as in the previous release. Castling moves
  are represented as a king move to the corresponding rook square.

  In the default standard chess mode castling moves are represented with
  the standard UCI notation, e.g. `e1g1` for king-side castling.

  `Board.uci(move, chess960=None)` creates UCI representations for moves.
  Unlike `Move.uci()` it can convert them in the context of the current
  position.

  `Board.has_chess960_castling_rights()` has been added to test for castling
  rights that are impossible in standard chess.

  The modules `chess.polyglot`, `chess.pgn` and `chess.uci` will transparently
  handle both modes.

* In a previous release `Board.fen()` has been changed to only display an
  en passant square if a legal en passant move is indeed possible. This has
  now also been adapted for `Board.shredder_fen()` and `Board.epd()`.

New features:

* Get individual FEN components: `Board.board_fen()`, `Board.castling_xfen()`,
  `Board.castling_shredder_fen()`.

* Use `Board.has_legal_en_passant()` to test if a position has a legal
  en passant move.

* Make `repr(board.legal_moves)` human readable.

python-chess v0.10.1

Bugfixes:

* Fix use-after-free in Gaviota tablebase initialization.

python-chess v0.10.0

New dependencies:

• If you are using Python < 3.2 you have to install futures in order to
  use the chess.uci module.

Changes:

• There are big changes in the UCI module. Most notably in async mode multiple
  commands can be executed at the same time (e.g. go infinite and then
  stop or go ponder and then ponderhit).

  go infinite and go ponder will now wait for a result, i.e. you may have
  to call stop or ponderhit from a different thread or run the commands
  asynchronously.

  stop and ponderhit no longer have a result.

• The values of the color constants chess.WHITE and chess.BLACK have been
  changed. Previously WHITE was 0, BLACK was 1. Now WHITE is True,
  BLACK is False. The recommended way to invert color is using
  not color.

• The pseudo piece type chess.NONE has been removed in favor of just using
  None.

• Changed the Board(fen) constructor. If the optional fen argument is not
  given behavior did not change. However if None is passed explicitly an
  empty board is created. Previously the starting position would have been
  set up.

• Board.fen() will now only show completely legal en-passant squares.

• Board.set_piece_at() and Board.remove_piece_at() will now clear the
  move stack, because the old moves may not be valid in the changed position.

• Board.parse_uci() and Board.push_uci() will now accept null moves.

• Changed shebangs from #!/usr/bin/python to #!/usr/bin/env python for
  better virtualenv support.

• Removed unused game data files from repository.

Bugfixes:

• PGN: Prefer the game result from the game termination marker over * in the
  header. These should be identical in standard compliant PGNs. Thanks to
  Skyler Dawson for reporting this.
• Polyglot: minimum_weight for find(), find_all() and choice() was
  not respected.
• Polyglot: Negative indexing of opening books was raising IndexError.
• Various documentation fixes and improvements.

New features:

• Experimental probing of Gaviota tablebases via libgtb.

• New methods to construct boards:

  >>> chess.Board.empty()
  Board('8/8/8/8/8/8/8/8 w - - 0 1')
  

  >>> board, ops = chess.Board.from_epd("4k3/8/8/8/8/8/8/4K3 b - - fmvn 17; hmvc 13")
  >>> board
  Board('4k3/8/8/8/8/8/8/4K3 b - - 13 17')
  >>> ops
  {'fmvn': 17, 'hmvc': 13}
  

• Added Board.copy() and hooks to let the copy module to the right thing.

• Added Board.has_castling_rights(color),
  Board.has_kingside_castling_rights(color) and
  Board.has_queenside_castling_rights(color).

• Added Board.clear_stack().

• Support common set operations on chess.SquareSet().

python-chess v0.9.1

Bugfixes:

• UCI module could not handle castling ponder moves. Thanks to Marco Belli for
  reporting.
• The initial move number in PGNs was missing, if black was to move in the
  starting position. Thanks to Jürgen Précour for reporting.
• Detect more impossible en-passant squares in Board.status(). There already
  was a requirement for a pawn on the fifth rank. Now the sixth and seventh
  rank must be empty, additionally. We do not do further retrograde analisys,
  because these are the only cases affecting move generation.

python-chess v0.8.3

Bugfixes:

• The initial move number in PGNs was missing, if black was to move in the
  starting position. Thanks to Jürgen Précour for reporting.
• Detect more impossible en-passant squares in Board.status(). There already
  was a requirement for a pawn on the fifth rank. Now the sixth and seventh
  rank must be empty, additionally. We do not do further retrograde analysis,
  because these are the only cases affecting move generation.

python-chess v0.9.0

This is a big update with quite a few breaking changes. Carefully review
the changes before upgrading. It's no problem if you can not update right now.
The 0.8.x branch still gets bugfixes.

Incompatible changes:

• Removed castling right constants. Castling rights are now represented as a
  bitmask of the rook square. For example:

  .. code:: python

  >>> board = chess.Board()
  
  >>> # Standard castling rights.
  >>> board.castling_rights == chess.BB_A1 | chess.BB_H1 | chess.BB_A8 | chess.BB_H8
  True
  
  >>> # Check for the presence of a specific castling right.
  >>> can_white_castle_queenside = chess.BB_A1 & board.castling_rights
  

  Castling moves were previously encoded as the corresponding king movement in
  UCI, e.g. e1f1 for white kingside castling. Now castling moves are
  encoded as a move to the corresponding rook square (UCI_Chess960-style),
  e.g. e1a1.

  You may use the new methods Board.uci(move, chess960=True),
  Board.parse_uci(uci) and Board.push_uci(uci) to handle this
  transparently.

  The uci module takes care of converting moves when communicating with an
  engine that is not in UCI_Chess960 mode.

• The get_entries_for_position(board) method of polyglot opening book readers
  has been changed to find_all(board, minimum_weight=1). By default entries
  with weight 0 are excluded.

• The Board.pieces lookup list has been removed.

• In 0.8.1 the spelling of repetition (was repitition) was fixed.
  can_claim_threefold_repetition() and is_fivefold_repetition() are the
  affected method names. Aliases are now removed.

• Board.set_epd() will now interpret bm, am as a list of moves for the
  current position and pv as a variation (represented by a list of moves).
  Thanks to Jordan Bray for reporting this.

• Removed uci.InfoHandler.pre_bestmove() and
  uci.InfoHandler.post_bestmove().

• uci.InfoHandler().info["score"] is now relative to multipv. Use

  .. code:: python

  >>> with info_handler as info:
  ...     if 1 in info["score"]:
  ...         cp = info["score"][1].cp
  

  where you were previously using

  .. code:: python

  >>> with info_handler as info:
  ...     if "score" in info:
  ...         cp = info["score"].cp
  

• Clear uci.InfoHandler() dictionary at the start of new searches
  (new on_go()), not at the end of searches.

• Renamed PseudoLegalMoveGenerator.bitboard and LegalMoveGenerator.bitboard
  to PseudoLegalMoveGenerator.board and LegalMoveGenerator.board,
  respectively.

• Scripts removed.

• Python 3.2 compability dropped. Use Python 3.3 or higher. Python 2.7 support
  is not affected.

New features:

• Introduced Chess960 support. Board(fen) and Board.set_fen(fen) now
  support X-FENs. Added Board.shredder_fen().
  Board.status(allow_chess960=True) has an optional argument allowing to
  insist on standard chess castling rules.
  Added Board.is_valid(allow_chess960=True).
• Improved move generation using Shatranj-style direct lookup <http://arxiv.org/pdf/0704.3773.pdf>_. Removed rotated bitboards. Perft
  speed has been more than doubled.
• Added choice(board) and weighted_choice(board) for polyglot opening book
  readers.
• Added Board.attacks(square) to determine attacks from a given square.
  There already was Board.attackers(color, square) returning attacks to
  a square.
• Added Board.is_en_passant(move), Board.is_capture(move) and
  Board.is_castling(move).
• Added Board.pin(color, square) and Board.is_pinned(color, square).
• There is a new method Board.pieces(piece_type, color) to get a set of
  squares with the specified pieces.
• Do expensive Syzygy table initialization on demand.
• Allow promotions like e8Q (usually e8=Q) in Board.parse_san() and
  PGN files.
• Patch by Richard C. Gerkin: Added Board.__unicode__() just like
  Board.__str__() but with unicode pieces.
• Patch by Richard C. Gerkin: Added Board.__html__().

python-chess v0.8.2

Bugfixes:

• pgn.Game.setup() with the standard starting position was failing when the
  standard starting position was already set. Thanks to Jordan Bray for
  reporting this.

Optimizations:

• Remove bswap() from Syzygy decompression hot path. Directly read integers
  with the correct endianness.

python-chess v0.8.1

Improvements in this bugfix release:

• Fixed pondering mode in uci module. For example ponderhit() was blocking
  indefinitely. Thanks to Valeriy Huz for reporting this.
• Patch by Richard C. Gerkin: Moved searchmoves to the end of the UCI go
  command, where it will not cause other command parameters to be ignored.
• Added missing check or checkmate suffix to castling SANs, e.g. O-O-O#.
• Fixed off-by-one error in polyglot opening book binary search. This would
  not have caused problems for real opening books.
• Fixed Python 3 support for reverse polyglot opening book iteration.
• Bestmoves may be literally (none) in UCI protocol, for example in
  checkmate positions. Fix parser and return None as the bestmove in this
  case.
• Fixed spelling of repetition (was repitition).
  can_claim_threefold_repetition() and is_fivefold_repetition() are the
  affected method names. Aliases are there for now, but will be removed in the
  next release. Thanks to Jimmy Patrick for reporting this.
• Added SquareSet.__reversed__().
• Use containerized tests on Travis CI, test against Stockfish 6, improved
  test coverage amd various minor clean-ups.