bombpass.py

all_poss = set("about after again below could every first found great house large learn never other place plant point right small sound spell still study their there these thing think three water where which world would write".split(' '))

def poss_matches(poss, dial, dialpos):
    return set([i for i in poss if i[dialpos] in dial])

def interact(prompt):
    curr = all_poss
    for i in xrange(5):
        while True:
            try:
                dialpos = int(prompt('Enter dial pos [0, 4]: '))
            except Exception:
                pass
            else:
                break
        chars = prompt('All characters on dial %d: '%(dialpos,))
        curr = poss_matches(curr, chars.lower(), dialpos)
        print 'Matches at this stage:'
        print curr

if __name__ == '__main__':
    interact(raw_input)