python-iso639

What it is and what it does

python-iso639 is a reference library for ISO 639 language codes and their associated metadata. It provides a Language class that maps across the three ISO 639 standard code sets (639-1 two-letter codes like 'fr', 639-2 three-letter codes in bibliographic and terminological variants like 'fre' and 'fra', and 639-3 codes like 'fra') to standardized language names and additional attributes. The package is optimized for fast lookups and includes a flexible matching method that can identify a language from any code or name format without requiring you to know which standard the input belongs to.

The library handles macrolanguages, alternative names, retired codes with retirement metadata, and language scope/type classification. It is designed for developers building multilingual applications, language processing pipelines, or data systems that need reliable language identification and normalization across different code standards.

Use it for:

• Normalize user-supplied language codes or names to a canonical ISO 639-3 code for storage or API calls.
• Build a language selector UI that accepts input in any ISO 639 format and returns consistent language metadata.
• Validate language codes in data pipelines and flag retired or unknown language identifiers.
• Resolve macrolanguage relationships (e.g., identifying that Yue Chinese belongs to the Chinese macrolanguage).
• Support multilingual search or filtering by accepting language input in any standard format.

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

Maps ISO 639 language codes (639-1, 639-2, 639-3) to language names and metadata, with methods to look up or guess a language from any code or name format.

Yes. The package is actively maintained, has no dependencies, installs with low friction, carries a permissive license, and solves a real problem for any project that needs reliable language code normalization. It is well-suited for production use in multilingual applications, data pipelines, and language-aware systems.

Install

python-iso639 on PyPI

pip install python-iso639

uv add python-iso639

poetry add python-iso639

Installing python-iso639

Before you install

Low install friction; pure Python wheel with no runtime dependencies. Active maintenance with a release 22 days ago; supports Python 3.10 through 3.14.

License in practice

Apache-2.0 permissive license allows use in commercial and proprietary projects with minimal restrictions.

Quickstart

pip install python-iso639

import iso639
lang = iso639.Language.from_part3('fra')
print(lang.name)  # 'French'

# Or guess from unknown input
lang = iso639.Language.match('fr')
print(lang.part3)  # 'fra'

Requires Python 3.10 or later.

Verify before relying

• Whether the package includes all current ISO 639-3 codes or a specific snapshot version.
• Performance characteristics for bulk lookups or large-scale matching operations.
• Whether macrolanguage and retired code handling covers all edge cases in production use.

Package facts

Evidence: python_iso639-2026.7.23-py3-none-any.whl

Keywords: ISO 639, language codes, languages, linguistics

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