Generate a CSV of patterns for a card game

generate_back_csv.py

#!/usr/bin/env python

import os
import random
from itertools import izip

def get_neighbors(coords):
    neighbors = set()
    for (x, y) in coords:
        neighbors.update(
            (X,Y) for (X,Y) in [
                (x-1, y),
                (x+1, y),
                (x, y-1),
                (x, y+1),
            ]
            if 0<=X<=3 and 0<=Y<=3 and (X,Y) not in coords)
    return list(neighbors)


def pick_hexomino():
    """Picks 6 contiguous coordinates in a 4x4 grid"""
    coords = {(random.randrange(4), random.randrange(4))}
    while len(coords) < 6:
        neighbors = get_neighbors(coords)
        new_coord = random.choice(neighbors)
        coords.add(new_coord)
    return sorted(4*x + y for (x,y) in coords)

def pick_outline():
    """Picks 6 random coordinates in a 4x4 grid"""
    return sorted(random.sample(xrange(16), 6))


PATTERN_CODE = {
    (0, 0): 'W',
    (1, 0): 'B',
    (0, 1): 'R',
    (1, 1): 'BR',
}

def create_card():
    hexomino_full = [0]*16
    for dot in pick_hexomino():
        hexomino_full[dot] = 1

    outline_full = [0]*16
    for dot in pick_outline():
        outline_full[dot] = 1

    return tuple(PATTERN_CODE[t] for t in izip(hexomino_full, outline_full))

def main():
    # Pick output file name
    base_filename = 'puzzle_backs'
    output_filename = base_filename
    n = 1
    while os.path.exists(output_filename + '.csv'):
        output_filename = base_filename + '_' + str(n)
        n += 1


    generated_puzzles = set()

    # Write to output filename
    with open(output_filename + '.csv', 'w') as f:
        header = ','.join('@'+l+str(n) for l in ['A','B','C','D'] for n in [1,2,3,4])
        f.write(header)
        f.write('\n')

        while len(generated_puzzles) < 50:
            new_puzzle = create_card()
            if new_puzzle in generated_puzzles:
                continue
            generated_puzzles.add(new_puzzle)
            card_row = ','.join(new_puzzle)
            f.write(card_row)
            f.write('\n')

if __name__ == '__main__':
    main()