queen.py

#!/usr/bin/env python

def game():
    pass

def load_plan(filename):
    """ loads a file called filename, from working 
        directory; expects data such as:
        ..#.
        ....
        ..#.
        .... 
        and turns them into list like this:
        [[0, 0, -1, 0],
         [0, 0,  0, 0],
         [0, 0, -1, 0],
         [0, 0,  0, 0]]
    """
    # secured opening, 'with' handles closing
    # the file on its own
    with open(filename, 'r') as f:
        board_str = f.readlines()

    board_lst = []
    for line in board_str:
        new_line = []
        for char in line:
            if char == '.':
                new_line.append(0)
            elif char == '#':
                new_line.append(-1)

        board_lst.append(new_line)
    return board_lst

def print_board(board):
    """ prints the board """

    for line in board:
        # use .rjust(2) for nice column formatting
        print ' '.join([str(x).rjust(2) for x in line])
    return

def dump_solution(board, filename):
    """ dumps solution for queen problem;
        expects e.g.
        [[2, 1, -1, 2],
         [1, 1,  2, 1],
         [1, 2, -1, 1],
         [1, 1,  1, 1]] 
        and creates a file called filename,
        which contains:
        2 1 # 2 
        1 1 2 1 
        1 2 # 1 
        1 1 1 1
    """
    solution = ''
    for line in board:
        for c in line:
            if c > 0:
                solution += str(c) +' '
            else:
                solution += '# '
        solution += '\n'

    with open(filename, 'w') as f:
        f.write(solution.strip())

    return

def solve_queen(board):
    pass

if __name__ == '__main__':

    print_board(load_plan('queen1'))
    dump_solution([[2, 1, -1, 2],
                   [1, 1,  2, 1],
                   [1, 2, -1, 1],
                   [1, 1,  1, 1]], 'queen1sol')

queen1sol

2 1 # 2
1 1 2 1
1 2 # 1
1 1 1 1