python-shogi: a pure Python shogi library

Introduction

This is the module for shogi written in Pure Python. It's based on python-chess commit

This is the scholars mate in python-shogi:

>>> import shogi

>>> board = shogi.Board()

>>> board.push(shogi.Move.from_usi('7g7f'))

>>> board.push_usi('3c3d')
Move.from_usi('3c3d')
>>> board.push_usi('8h2b+')
Move.from_usi('8h2b+')
>>> board.push_usi('4a5b')
Move.from_usi('4a5b')
>>> board.push_usi('B*4b')
Move.from_usi('B*4b')
>>> board.push_usi('5a4a')
Move.from_usi('5a4a')
>>> board.push_usi('2b3a')
Move.from_usi('2b3a')
>>> board.is_checkmate()
True

Features

• Supports Python 3.3+.
• Supports standard shogi (hon shogi)

• Legal move generator and move validation.

  >>> shogi.Move.from_usi("5i5a") in board.legal_moves
  False

• Make and unmake moves.

  >>> last_move = board.pop() # Unmake last move
  >>> last_move
  Move.from_usi('2b3a')
  
  >>> board.push(last_move) # Restore

• Show a simple ASCII board.

  >>> print(board)
   l  n  s  g  .  k +B  n  l
   .  r  .  .  g  B  .  .  .
   p  p  p  p  p  p  .  p  p
   .  .  .  .  .  .  p  .  .
   .  .  .  .  .  .  .  .  .
   .  .  P  .  .  .  .  .  .
   P  P  .  P  P  P  P  P  P
   .  .  .  .  .  .  .  R  .
   L  N  S  G  K  G  S  N  L
  <BLANKLINE>
   S*1

• Show a KIF style board.

  >>> print(board.kif_str())
  後手の持駒：
    ９ ８ ７ ６ ５ ４ ３ ２ １
  +---------------------------+
  |v香v桂v銀v金 ・v玉 馬v桂v香|一
  | ・v飛 ・ ・v金 角 ・ ・ ・|二
  |v歩v歩v歩v歩v歩v歩 ・v歩v歩|三
  | ・ ・ ・ ・ ・ ・v歩 ・ ・|四
  | ・ ・ ・ ・ ・ ・ ・ ・ ・|五
  | ・ ・ 歩 ・ ・ ・ ・ ・ ・|六
  | 歩 歩 ・ 歩 歩 歩 歩 歩 歩|七
  | ・ ・ ・ ・ ・ ・ ・ 飛 ・|八
  | 香 桂 銀 金 玉 金 銀 桂 香|九
  +---------------------------+
  先手の持駒：　銀

• Detects checkmates, stalemates.

  >>> board.is_stalemate()
  False
  >>> board.is_game_over()
  True

• Detects repetitions. Has a half move clock.

  >>> board.is_fourfold_repetition()
  False
  >>> board.move_number
  8

• Detects checks and attacks.

  >>> board.is_check()
  True
  >>> board.is_attacked_by(shogi.BLACK, shogi.A4)
  True
  >>> attackers = board.attackers(shogi.BLACK, shogi.H5)
  >>> attackers
  SquareSet(0b111000010000000000000000000000000000000000000000000000000000000000000000000000)
  >>> shogi.H2 in attackers
  True
  >>> print(attackers)
  . . . . . . . . .
  . . . . . . . . .
  . . . . . . . . .
  . . . . . . . . .
  . . . . . . . . .
  . . . . . . . . .
  . . . . . . . . .
  . . . . . . . 1 .
  . . . 1 1 1 . . .

• Parses and creates USI representation of moves.

  >>> board = shogi.Board()
  >>> shogi.Move(shogi.E2, shogi.E4).usi()
  '2e4e'

• Parses and creates SFENs

  >>> board.sfen()
  'lnsgkgsnl/1r5b1/ppppppppp/9/9/9/PPPPPPPPP/1B5R1/LNSGKGSNL b - 1'
  >>> board.piece_at(shogi.I5)
  Piece.from_symbol('K')

• Read KIFs.

  >>> import shogi.KIF
  
  >>> kif = shogi.KIF.Parser.parse_file('data/games/habu-fujii-2006.kif')[0]
  
  >>> kif['names'][shogi.BLACK]
  '羽生善治'
  >>> kif['names'][shogi.WHITE]
  '藤井猛'
  >>> kif['moves'] # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
  ['7g7f',
   '3c3d',
   ...,
   '9a9b',
   '7a7b+']
  >>> kif['win']
  'b'

• Export to KIFs.

  >>> import shogi
  >>> import shogi.KIF
  
  >>> board = shogi.Board()
  >>> shogi.KIF.Exporter.kif_move_from('7g7f', board)
  '７六歩(77)'
  
  >>> sfen_summary = {'moves': ['7g7f', '3c3d'], 'sfen': 'lnsgkgsnl/1r5b1/ppppppppp/9/9/9/PPPPPPPPP/1B5R1/LNSGKGSNL b - 1', 'names': ['羽生善治', '藤井猛'], 'win': 'w'}
  >>> shogi.KIF.Exporter.kif(sfen_summary)
  開始日時： \r
  終了日時： \r
  手合割：平手\r
  先手：羽生善治\r
  後手：藤井猛\r
  手数----指手---------消費時間-- \r
  1 ７六歩(77) \r
  2 ３四歩(33) \r
  3 投了 \r
  まで2手で後手の勝ち\r

• Communicate with a CSA protocol.

  Please see random_csa_tcp_match.

• Parse professional shogi players' name

  >>> import shogi.Person

  >>> shogi.Person.Name.is_professional('羽生　善治 名人・棋聖・王位・王座') True

Performance

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

You can install the gmpy2 or gmpy modules in order to get a slight performance boost on basic operations like bit scans and population counts.

python-shogi will only ever import very basic general (non-shogi-related) operations from native libraries. All logic is pure Python. There will always be pure Python fallbacks.

Installing

• With pip:

  pip install python-shogi

How to test

> make test

If you want to print lines from the standard output, execute nosetests like following.

> poetry run nosetests -s

How to release

poetry config repositories.testpypi https://test.pypi.org/legacy/
# poetry config pypi-token.testpypi "Test PyPI API Token"
make test-upload
# poetry config pypi-token.pypi "PyPI API Token"
make upload

ToDo

• Support board.generate_attacks() and use it in board.is_attacked_by() and board.attacker_mask().
• Remove rotated bitboards and support Shatranj-style direct lookup like recent python-chess.
• Support %MATTA etc. in CSA TCP Protocol.
• Support board.is_pinned() and board.pin().