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"""Soundex algorithm
This program is part of "Dive Into Python", a free Python book for
experienced programmers. Visit http://diveintopython.org/ for the
latest version.
"""
__author__ = "Mark Pilgrim (mark@diveintopython.org)"
__version__ = "$Revision: 1.5 $"
__date__ = "$Date: 2004/05/11 19:11:21 $"
__copyright__ = "Copyright (c) 2004 Mark Pilgrim"
__license__ = "Python"
import string
allChar = string.uppercase + string.lowercase
charToSoundex = string.maketrans(allChar, "91239129922455912623919292" * 2)
def soundex(source):
"convert string to Soundex equivalent"
# Soundex requirements:
# source string must be at least 1 character
# and must consist entirely of letters
if (not source) or (not source.isalpha()):
return "0000"
# Soundex algorithm:
# 1. make first character uppercase
# 2. translate all other characters to Soundex digits
digits = source[0].upper() + source[1:].translate(charToSoundex)
# 3. remove consecutive duplicates
digits2 = digits[0]
for d in digits[1:]:
if digits2[-1] != d:
digits2 += d
# 4. remove all "9"s
# 5. pad end with "0"s to 4 characters
return (digits2.replace('9', '') + '000')[:4]
if __name__ == '__main__':
import sys
if sys.argv[1:]:
print soundex(sys.argv[1])
else:
from timeit import Timer
names = ('Woo', 'Pilgrim', 'Flingjingwaller')
for name in names:
statement = "soundex('%s')" % name
t = Timer(statement, "from __main__ import soundex")
print name.ljust(15), soundex(name), min(t.repeat())