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Fast banded edit distance

Project description



A small Python module providing edit distance (aka Levenshtein distance, that is, counting insertions, deletions and substitutions) and Hamming distance computation.

Its main purpose is to speed up computation of edit distance by allowing to specify a maximum number of differences maxdiff (banding). If that parameter is provided, the returned edit distance is anly accurate up to maxdiff. That is, if the actual edit distance is higher than maxdiff, a value larger than maxdiff is returned, but not necessarily the actual edit distance.

For computing regular edit distances or if your maxdiff is less than 4, you should prefer, as that is faster in that case. When maxdiff is 4 or more, but not too close to the length of the shortest string, this module is faster.

>>> from tinyalign import edit_distance, hamming_distance
>>> edit_distance("banana", "ananas")
>>> hamming_distance("hello", "yello")
>>> edit_distance("hello", "world", maxdiff=2)

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