polyleven
A fast C-implemented library for Levenshtein distance
Decision gist · record as of 2026-08-14
Yes, if you need fast Levenshtein distance computation. The library is mature (Production/Stable), has no dependencies, supports current Python versions, and shows strong performance. Caveat: verify the license metadata before use in proprietary projects, as the license treatment is marked unclear despite the description claiming MIT.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.8 or later; compiled wheels available for most platforms but source build may require a C compiler.
- Medium install friction due to compiled wheels, but pre-built binaries are available for common platforms (Python 3.10–3.12 on macOS, Linux, Windows, and ARM).
- Last release was 186 days ago; repo is active and not archived.
License · maintenance · safety
(unclear) — License treatment is unclear in the metadata, though the description states MIT License. Verify the actual license terms before use in proprietary projects.
last release 2026-02-09 (186 days) · last repo commit 2026-02-09 · 87 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 4,665,512 downloads/mo, #2,261 on PyPI
Alternatives
Verify before relying
pip install polyleven
from polyleven import levenshtein
print(levenshtein('aaa', 'ccc')) # Output: 3
print(levenshtein('acc', 'ccc', 1)) # With threshold: 1- License metadata is marked unclear despite description stating MIT—confirm actual license terms before use.
- Performance claims in description (e.g., 2303420 pairs/sec) are from benchmarks on Python 3.5.3; current performance on modern Python versions unknown.
What it is and what it does
Polyleven is a C-implemented library that calculates the Levenshtein distance (edit distance) between two strings. It measures how many single-character edits—insertions, deletions, or substitutions—are needed to transform one string into another. The library is designed to be fast across both short inputs like English words and long inputs like DNA sequences, with no external dependencies beyond Python itself.
You use it by importing the `levenshtein()` function and passing two strings; it returns the distance as an integer. Optionally, you can provide a threshold as a third argument to stop early if the distance exceeds that limit, which can speed up comparisons when you only care whether strings are similar within a certain tolerance.
Use it for
- Spell-checking and autocorrect: find candidate words within a fixed edit distance of a misspelled input.
- Duplicate detection: identify similar records in datasets by comparing strings with a distance threshold.
- DNA/protein sequence analysis: compute alignment distances for biological sequences.
- Fuzzy string matching in search: rank results by similarity to a query term.
- Data deduplication: flag records that are nearly identical but not exact matches.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you need fast Levenshtein distance computation.
The library is mature (Production/Stable), has no dependencies, supports current Python versions, and shows strong performance. Caveat: verify the license metadata before use in proprietary projects, as the license treatment is marked unclear despite the description claiming MIT.
Install
polyleven on PyPI
Before you install
Medium install friction due to compiled wheels, but pre-built binaries are available for common platforms (Python 3.10–3.12 on macOS, Linux, Windows, and ARM). Last release was 186 days ago; repo is active and not archived.
Requires Python 3.8 or later; compiled wheels available for most platforms but source build may require a C compiler.
License in practice
License treatment is unclear in the metadata, though the description states MIT License. Verify the actual license terms before use in proprietary projects.
Quickstart
pip install polyleven
from polyleven import levenshtein
print(levenshtein('aaa', 'ccc')) # Output: 3
print(levenshtein('acc', 'ccc', 1)) # With threshold: 1Verify before relying
- License metadata is marked unclear despite description stating MIT—confirm actual license terms before use.
- Performance claims in description (e.g., 2303420 pairs/sec) are from benchmarks on Python 3.5.3; current performance on modern Python versions unknown.
Package facts
| License | Not declared unclear |
| Python support | Supports the current Python release >=3.8 |
| Install friction | Medium. Platform-specific wheel |
| Runtime dependencies | None |
| Maintenance | Aging 186 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 4,665,512 / month, #2,261 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableOperating System :: OS IndependentProgramming Language :: CProgramming Language :: Python :: 3 |
Evidence: polyleven-0.11.0-cp310-cp310-macosx_10_9_x86_64.whl; polyleven-0.11.0-cp310-cp310-macosx_11_0_arm64.whl; polyleven-0.11.0-cp310-cp310-manylinux1_x86_64.manylinux_2_28_x86_64.manylinux_2_5_x86_64.whl; polyleven-0.11.0-cp310-cp310-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl; polyleven-0.11.0-cp310-cp310-musllinux_1_2_aarch64.whl; polyleven-0.11.0-cp310-cp310-musllinux_1_2_x86_64.whl; polyleven-0.11.0-cp310-cp310-win32.whl; polyleven-0.11.0-cp310-cp310-win_amd64.whl; polyleven-0.11.0-cp310-cp310-win_arm64.whl; polyleven-0.11.0-cp311-cp311-macosx_10_9_x86_64.whl; polyleven-0.11.0-cp311-cp311-macosx_11_0_arm64.whl; polyleven-0.11.0-cp311-cp311-manylinux1_x86_64.manylinux_2_28_x86_64.manylinux_2_5_x86_64.whl; polyleven-0.11.0-cp311-cp311-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl; polyleven-0.11.0-cp311-cp311-musllinux_1_2_aarch64.whl; polyleven-0.11.0-cp311-cp311-musllinux_1_2_x86_64.whl; polyleven-0.11.0-cp311-cp311-win32.whl; polyleven-0.11.0-cp311-cp311-win_amd64.whl; polyleven-0.11.0-cp311-cp311-win_arm64.whl; polyleven-0.11.0-cp312-cp312-macosx_10_13_x86_64.whl; polyleven-0.11.0-cp312-cp312-macosx_11_0_arm64.whl
Tags
Let your AI agent find packages like this
Example. Real query, live index.
You found this page by searching. An agent finds it by wishing: SkillFed indexes 14,416 PyPI packages by what they can do, searchable in plain language.
wish › “levenshtein distance”
- polylevenPolyleven computes Levenshtein distance between two strings using a…
- editdistpyComputes Levenshtein and Damerau-Levenshtein edit distances between…
- editdistanceComputes the edit distance (Levenshtein distance) between two…
Give your agent the search over MCP, or paste the wish link into any chat.
More Text Processing packages
A drop-in replacement for Python's standard `re` module that adds advanced regex features like nested sets, fuzzy matching, lookaround in conditionals, and full Unicode case-folding while maintaining backward compatibility.
pyparsing provides a library for building text parsers directly in Python code using composable grammar classes, handling quoted strings, whitespace variation, and embedded comments without regex or lex/yacc.
Install it if you need to parse text or define grammars programmatically.
fonttools manipulates font files in multiple formats (TrueType, OpenType, AFM, Type 1, Mac-specific) and includes TTX, a tool to convert fonts to and from XML text format.
Install it if you need to read, write, or manipulate fonts programmatically or via the TTX command-line tool.
Docutils converts plaintext documentation in reStructuredText format into multiple output formats including HTML, XML, and LaTeX using a modular processing system.
RapidFuzz provides fast fuzzy string matching using Levenshtein Distance and related metrics, implemented mostly in C++ with Python bindings for rapid similarity scoring and approximate string matching.
Install it if you need fuzzy string matching; it's a solid replacement for FuzzyWuzzy with better licensing and performance.
tinycss2 parses CSS strings into token and block objects, and generates CSS strings from those objects, following the CSS Syntax Level 3 specification without enforcing specific properties or values.
Install it if your project requires CSS tokenization or syntax manipulation.
See also python-Levenshtein · editdistance · edlib · Levenshtein · editdistpy · Distance · textdistance · stringzilla · strsimpy · pylcs