Single_Player_Chess/chess.py

from unicodedata import lookup

def cross(A, B):
    return tuple(a+b for a in A for b in B)

ranks   = "12345678"
files   = "abcdefgh"
squares = cross(files, ranks)

pawn_ranks = "27"
home_ranks = "18"
init_positions = {"pawn"   : cross(files, pawn_ranks),
                  "rook"   : cross("ah",  home_ranks),
                  "knight" : cross("bg",  home_ranks),
                  "bishop" : cross("cf",  home_ranks),
                  "queen"  : cross("d",   home_ranks),
                  "king"   : cross("e",   home_ranks)
                 }


class Piece:
    def __init__(self, color=None, piece=None):
        self.color = color
        self.piece = piece

    def __repr__(self):
        if None in (self.piece, self.color):
            return None
        name = self.color.upper() + " CHESS " + self.piece.upper()
        return lookup(name)

class Game:
    def __init__(self):
        self.make_board()

    def __repr__(self):
        # Unicode board representation
        r = ""
        for rank in ranks:
            r += rank + " |"
            for file in files:
                sq = file+rank
                r += " "
                if self.is_empty(sq):
                    r += " "
                else:
                    r += repr(self.board[sq])
            r += "\n"
        r += "  +" + "-"*16 + "\n"
        r += " "*4 + " ".join(list(files))
        return r

    def make_board(self):
        self.board = dict((sq, Piece()) for sq in squares)
        # Add pieces
        for piece, positions in init_positions.items():
            for sq in positions:
                self.board[sq].piece = piece
        # Add colors
        for sq in cross(files, "12"):
            self.board[sq].color = "white"
        for sq in cross(files, "78"):
            self.board[sq].color = "black"

    def is_empty(self, sq):
        return self.board[sq].piece == None




def test():
    game = Game()
    assert len(squares) == 8**2
    assert sum(map(len, init_positions.values())) == 8*4
    print(game)

test()