part of a larger program

maze.py

#!/bin/python
# encoding: utf-8

import random

# DIMENSIONS MUST BE ODD!
WIDTH = 17
HEIGHT = 17
SQUARE = 14

neighborhood = (-1, 0), (1, 0), (0, -1), (0, 1)
def printmaze(): # Crude testing function.
    print
    for line in maze:
        print "".join((" ", "#")[m] for m in line)

# Set up stuff.
maze = [[0]*WIDTH for j in range(HEIGHT)]

def in_boundaries(x, y): # checks if a position isn't out of bounds of the maze.
    if x >= WIDTH or x < 0:
        return False
    if y >= HEIGHT or y < 0:
        return False
    return True

# Generates a random connected maze using a trivial algorithm.
# Starts on a random odd square and draws a wall in a random direction,
# until there is no free odd square left.
# Guaranteed (?) to be connected as long as the maze dimensions are odd.

while True:
    # Find all free odd squares.
    locs = []
    for x in range(1, (WIDTH // 2)+1):
        for y in range(1, (HEIGHT // 2)+1):
            px, py = (x*2)-1, (y*2)-1
            if maze[py][px] == 0:
                locs.append((px, py))

    # If there are no free squares, we're done.
    if not locs: break
    
    # Pick a random starting point and direction.
    x, y = random.choice(locs)           
    xvel, yvel = random.choice((neighborhood))

    # Draw the wall as far as possible.
    while True:
        if not in_boundaries(x, y):
            break
        if maze[y][x] == 1:
            break
        maze[y][x] = 1
        x += xvel
        y += yvel

# Find all free squares
free = []
for x in range(WIDTH):
    for y in range(HEIGHT):
        if maze[y][x] == 0:
            free.append((x, y))

# Random positions:
px, py = random.choice(free) # player
free.remove((px, py))
gx, gy = random.choice(free) # goal

printmaze()