python-chess: a chess library

Introduction

This is the scholars mate in python-chess:

pos = chess.Position()
pos.make_move_from_san("e4")
pos.make_move_from_san("e5")
pos.make_move_from_san("Qh5")
pos.make_move_from_san("Nc6")
pos.make_move_from_san("Bc4")
pos.make_move_from_san("Nf6")
pos.make_move_from_san("Qxf7")
assert pos.is_checkmate()

Features

• Legal move generator and move validation. This includes all castling rules and en-passant captures.

  assert not chess.Move.from_uci("a8a1") in pos.get_legal_moves()
  

• Detects checkmates, stalemates and draws by insufficient material. Has a half-move clock.

  assert not pos.is_stalemate()
  assert not pos.is_insufficient_material()
  assert pos.is_game_over()
  

• Detects checks and can enumerate attackers and defenders of a square.

  assert pos.is_check()
  assert chess.Square("f7") in pos.get_attackers("w", chess.Square("e8"))
  

• Parses and creates SAN representation of moves.

  pos = chess.Position()
  assert "e4" == pos.make_move(chess.Move("e2e4")).san
  

• Parses and creates FENs.

  assert pos.fen == "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
  pos = chess.Position("8/8/8/2k5/4K3/8/8/8 w - - 4 45")
  assert pos["c5"] == chess.Piece("k")
  

• Read Polyglot opening books.

  book = chess.PolyglotOpeningBook("data/opening-books/performance.bin")
  pos = chess.Position()
  for entry in book.get_entries_for_position(pos):
      assert chess.Move.from_uci("e2e4") == entry.move
      break
  

Peformance

python-chess is not intended to be used by chess engines where performance is critical. The goal is rather to create a simple and highlevel library.

However parts like move generation are in C++ (see the libchess directory) to improve the performance over pure Python code.

Building

libboost-regex-dev and libboost-python-dev are required.

• With easy_install:

  sudo easy_install python-chess
  

• From current source code:

  python setup.py build
  sudo python setup.py install
  

License

python-chess is licensed under the GPL3. See the LICENSE file for the full copyright and license information.