Solution for Code Jam Problem C https://code.google.com/codejam/contest/dashboard?c=351101#s=p2

t9_speller.py

key_mapping = [
    ('abc',  '2'),
    ('def',  '3'),
    ('ghi',  '4'),
    ('jkl',  '5'),
    ('mno',  '6'),
    ('pqrs', '7'),
    ('tuv',  '8'),
    ('wxyz', '9'),
    (' ',    '0'),
]

translation_table = {'\n': '\n'}

for ascii, key in key_mapping:
    for c in ascii:
        translation_table[c] = (ascii.index(c)+1) * key

lines = open('C-large-practice.in').readlines()[1:]
with open('C-large-practive.out', 'w') as out:
    for i, line in enumerate(lines):
        result = []
        for c in line:
            if result and translation_table[c][0] == result[-1][0]:
                result.append(' ')
            result.append(translation_table[c])
        out.write('Case #%d: %s' % (i+1, ''.join(result)))