tslmy tslmy - 1 month ago 11
Python Question

Python "regex" module: Fuzziness value

I'm using the "fuzzy match" functionality of the Regex module.

How can I get the "fuzziness value" of a "match" which indicates how different the pattern is to the string, just like the "edit distance" in Levenshtein?

I thought I could get the value in the Match object, but it's not there. The official docs said nothing about it, neither.

e.g.:

regex.match('(?:foo){e}','for')


a.captures()
tells me that the word "for" is matched, but I'd like to know the fuzziness value, which should be
1
in this case.

Is there any way to achieve that?

Answer Source
>>> import difflib
>>> matcher = difflib.SequenceMatcher(None, 'foo', 'for')
>>> sum(size for start, end, size in matcher.get_matching_blocks())
2
>>> max(map(len, ('foo', 'for'))) - _
1
>>>
>>>
>>> matcher = difflib.SequenceMatcher(None, 'foo', 'food')
>>> sum(size for start, end, size in matcher.get_matching_blocks())
3
>>> max(map(len, ('foo', 'food'))) - _
1

http://docs.python.org/2/library/difflib.html#difflib.SequenceMatcher.get_matching_blocks http://docs.python.org/2/library/difflib.html#difflib.SequenceMatcher.get_opcodes