fix: prevent ZeroDivisionError in token-based algorithms for short sequences - #97
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gaoflow wants to merge 1 commit into
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fix: prevent ZeroDivisionError in token-based algorithms for short sequences#97gaoflow wants to merge 1 commit into
gaoflow wants to merge 1 commit into
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…rter than qval When qval > 1 and the input sequence is shorter than qval characters, find_ngrams returns an empty list, causing _get_sequences to produce empty sequences. Token-based algorithms (Jaccard, Sorensen, Overlap, Cosine, Tversky) then divide by zero when computing intersection/denominator. Fall back to individual characters via list(s) when n-gram extraction yields no n-grams, preserving the information in the input sequence rather than silently treating it as empty.
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When
qval > 1and an input sequence has fewer charactersthan
qval,find_ngrams()returns an empty list. Token-basedsimilarity algorithms (Jaccard, Sorensen, Overlap, Cosine,
Tversky) crash with
ZeroDivisionErrorbecause the emptyn-gram lists produce zero denominators.
Fix (+1 char):
find_ngrams(s, self.qval) or list(s)—when n-gram extraction yields nothing for a non-empty sequence,
fall back to individual characters. This preserves the intended
semantics: short strings are compared by their constituent
characters instead of being silently treated as empty.
Reproduction:
404/404 tests pass (26 hypothesis deadline flakes pre-existing).
This pull request was prepared with the assistance of AI, under my
direction and review.