import random
lifechance = .1 ## 10 % chance for life in square
board = []
for x in range (50):
    # '*' == life, '' == dead
    board.append(['*' if random.random()<lifechance else ''
                  for notcare in range(50)])
# make strings for lines replacing '' values (which are considered False) with ' '
print '\n'.join(''.join(life if life else ' '
                        for life in row)
                for row in board)