hangman

'''
Sample Output:
Solution: Python is Cool
______ __ ____
Next Guess: p
p_____ __ ____
Next Guess: o
p___o_ __ _oo_
Next Guess: t
p_t_o_ __ _oo_
Next Guess: h
p_tho_ __ _oo_
Next Guess: y
pytho_ __ _oo_
Next Guess: n
python __ _oo_
Next Guess: s
python _s _oo_
Next Guess: i
python is _oo_
Next Guess: c
python is coo_
Next Guess: l
Solved! Answer: Python is Cool
'''

import string

solution = raw_input('Solution: ').lower()
guessed = set()
required = set(s for s in solution if s in string.ascii_lowercase)

def mask_character(c):
    if c in string.ascii_lowercase:
        if not c in guessed:
            return '_'
    return c

while guessed ^ required:
    print ''.join(mask_character(c) for c in solution)
    char = raw_input('Next Guess: ').strip()
    if char and char[0] in string.ascii_letters:
        guessed.add(char[0].lower())
    
    
print 'Solved! Answer:', solution