floof 0.1.3

A library for fuzzymatching

floof: simple fuzzymatching / comparison library

What is it?

floof is a Python package that makes fuzzymatching easy. Fuzzymatching is a common data task required whenever two strings don't quite exactly match. There are many algorithms to calculate string similarity, with dozens of disparate implementations. floof aims to collect all of these in an easy-to-use package, and reduce the boilerplate needed to apply these algorithms to your data.

Usage:

Dependencies

• [fast_distance - Fast C, ascii-only implementation of Hamming and Damerau-Levenshtein]
• [jarowinkler - Fast implementation of Jaro and Jaro-Winkler algorithms]
• [jellyfish - Implements many edit distance algorithms, including Damerau-Levenshtein]
• [Levenshtein - Fast C implementation of Levenshtein distance]
• [sklearn - Used to implement TFIDF]

Installing

The easiest way is to install floof is from PyPI using pip:

pip install floof

Running

First, import the library.

import floof

Floof provides two classes: Comparer and Matcher. Both are instantiated the same way, taking as arguments two Pandas Series, an "original" and a "lookup", although in practice the order doesn't madder.

matcher = floof.Matcher(original, lookup)
comparer = floof.Comparer(original, lookup)

All functions in the Matcher class return a crosswalk of the original strings and the best k matches from the lookup strings. The primary convenience function is floof.Matcher().match(), which applies several different similarity algorithms and produces a composite score. Given an example input of:

original_names = ["apple", "pear"]
lookup_names = ["appl", "apil", "prear"]

A matcher function would return something like:

original_name	lookup_name	levenshtein_score	tfidf_score	final_score
apple	appl	90	80	85
apple	apil	70	85	77.5
pear	prear	95	90	92.5

The Comparer class is meant to compare strings one-to-one. That is to say, given an input of:

original_names = ["apple", "pear"]
lookup_names = ["appl", "apil"]

A comparer function would return something like:

levensthein_score
90
95

Performance

Fuzzymatching can be very intense, as many algorithms are by nature quadratic. For each original string, you must compare against all lookup strings. Therefore, floof is by default concurrent. It also can perform common-sense speedups, like first removing exact matches from the pool, and using a non-quadratic algorithm (TFIDF) to filter the pool.

TODO:

• Allow custom scorers