Modified phone2numeric to not use regular expression or lambdas

def phone2numeric(phone):

    "Converts a phone number with letters into its numeric equivalent."

    letters = re.compile(r'[A-Z]', re.I)

    char2number = lambda m: {'a': '2', 'b': '2', 'c': '2', 'd': '3', 'e': '3',

         'f': '3', 'g': '4', 'h': '4', 'i': '4', 'j': '5', 'k': '5', 'l': '5',

         'm': '6', 'n': '6', 'o': '6', 'p': '7', 'q': '7', 'r': '7', 's': '7',

         't': '8', 'u': '8', 'v': '8', 'w': '9', 'x': '9', 'y': '9', 'z': '9',

        }.get(m.group(0).lower())

    return letters.sub(char2number, phone)

phone2numeric = allow_lazy(phone2numeric)

    char2number = {'a': '2', 'b': '2', 'c': '2', 'd': '3', 'e': '3', 'f': '3',

         'g': '4', 'h': '4', 'i': '4', 'j': '5', 'k': '5', 'l': '5', 'm': '6',

         'n': '6', 'o': '6', 'p': '7', 'q': '7', 'r': '7', 's': '7', 't': '8',

         'u': '8', 'v': '8', 'w': '9', 'x': '9', 'y': '9', 'z': '9',

        }

    return u''.join(char2number.get(c,c) for c in phone.lower())

# From http://www.xhaus.com/alan/python/httpcomp.html#gzip

# Used with permission.