python: comparing two strings

Question

I would like to know if there is a library that will tell me approximately how similar two strings are

I am not looking for anything specific, but in this case:

a = 'alex is a buff dude'
b = 'a;exx is a buff dud'

we could say that b and a are approximately 90% similar.

Is there a library which can do this?

Answer 1

import difflib

>>> a = 'alex is a buff dude'
>>> b = 'a;exx is a buff dud'
>>> difflib.SequenceMatcher(None, a, b).ratio()

0.89473684210526316

Answer 2

http://en.wikipedia.org/wiki/Levenshtein_distance

There are a few libraries on pypi, but be aware that this is expensive, especially for longer strings.

You may also want to check out python's difflib: http://docs.python.org/library/difflib.html