Chess AI

A rudimentary, simple, and hopefully easy to understand chess engine.

Features (or Lack Thereof)

Board and gameplay are pretty-printed
Human vs. Computer and Computer vs. Computer games can be played/observed
Pre-initialized boards from strings can be passed in
Evaluates using piece value and positional reasoning
Castling, en passant, and pawn promotions are NOT handled

Development

Handle castling, en passant, and pawn promotion
Correctly profile move evalution code, logic, and functions
Clean up move generation code (maybe?)
Clean up positional reasoning code
~~Create a game manager that handles two-player games~~
~~Allow passing in initial board configs as strings to be automatically converted~~
~~Use a smarter board-heuristic based on move instead of recalculating for whole board~~

Installation

Clone / download this repository.
Run the src/main.py file with Python 3 to quickly play a game against the engine.

Usage

The primary interface will be GameManager or ChessGame which allows for game creation and management.

Note that colors are represented as follows:

white = 10
black = 20

Playing a Human vs. Computer Game

import GameManager

game = GameManager.HumanvAIGame(10)   # Human player is white

game.play()   # Will play an interactive game in the CLI

Observing Computer vs. Computer Game

# Initialize with different "difficulty" levels (max game-tree evaluation)
game = GameManager.AIvAIGame(whiteMaxDepth=2, blackMaxDepth=3)

# Play one computer move each
game.playOneMove()

# Play 7 computer moves each, supressing board output
game.playNMove(7, printBoards=False)

# Play against each other until game finished, printing boards and move choices
game.playUntilDone(printStuff=True)

Multiple Computer vs. Computer Game Statistics

game = GameManager.AIvAIGame(whiteMaxDepth=2, blackMaxDepth=3)

# Play 20 entire games from start to finish, displaying win/loss statistics once completed
# Warning, can be very slow if choosing moves takes a while (if maxDepth is high)
game.playNTimes(20)

Generating Move from Pre-Initialized Board

import ChessGame

player = 20   # Set active player for this ChessGame view as black

# Create initial board configuration as a string, {upper-case: white, lower-case: black, dash: empty}
# Only requirement is that it MUST contain two opposing kings
board = ('r n - q k b n -'
         '- p - p p p p p'
         'b - - - - - - r'
         '- - - - - - - -'
         '- - - P - - Q -'
         'P - - - - - - -'
         '- P P - P - P P'
         'R - B - K - N -')

# Create game, passing in active player and initial board string
game = ChessGame.ChessGame(player, initBoard=board)

# Find best move, searching game-tree 3 levels deep
bestMove = game.getMove(maxDepth=3)

# Make the found best move, changing current board state
game.makeMove(bestMove)

# Pretty print current game board
print(game)

gunvirranu/chess-ai