---
id: feu
version: "0.8.1"
license: BSD-3-Clause
license_treatment: permissive
maintenance: active
---

# feu — A lightweight Python library for managing packages and versions across different Python environments

License: permissive · Maintenance: active · Downloads: 938.0K/mo

## What it is and what it does

feu is a lightweight library that automates Python package version management across different Python environments. It solves the problem of manually tracking which package versions work with which Python versions by providing tools to check package availability, discover compatible versions from PyPI, and validate versions before installation. The core functionality depends only on packaging, with optional dependencies for CLI tools and GitHub integration.

Typically used when you need to support multiple Python versions in a project or when deploying code to environments with different Python versions and package availability. It includes a built-in registry of compatibility information for popular packages like numpy, pandas, and torch, and falls back to PyPI discovery for packages not in the registry.

Use it for:

- Verify if a package is installed and get its version before attempting to use it in your code.
- Find the closest compatible version of a package for a specific Python version before installation.
- Automate version selection in CI/CD pipelines to prevent installation failures across multiple Python versions.
- Build tools that need to discover and install packages with automatic version compatibility checks.
- Support multi-version Python projects by querying compatibility across different target environments.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

feu checks package availability, resolves compatible versions across Python environments, and manages package installations with automatic version compatibility validation.

Yes, if you need to manage package versions across multiple Python environments or automate version compatibility checks. The low install friction, active maintenance, permissive license, and zero known vulnerabilities make it a safe choice. Start with the basic import/version-check functions; the CLI and GitHub utilities are optional. Not necessary if you only target a single Python version or manually manage dependencies.

## Install

pip install feu
uv add feu
poetry add feu

## Installing feu

Before you install: Low install friction with only packaging and tomli as runtime dependencies. Active maintenance with a release 4 days ago; repository shows recent activity.

License in practice: BSD-3-Clause is permissive; you can use, modify, and distribute feu with minimal restrictions, provided you include the license notice.

Quickstart:

pip install feu

from feu.imports import is_package_available
from feu.compat import Target, find_closest_version

if is_package_available("numpy"):
    version = find_closest_version(
        pkg_name="numpy", pkg_version="2.0.2", target=Target(python_version="3.10")
    )
    print(f"Closest valid version: {version}")

Requires Python 3.10 or later.

Verify before relying:

- Whether built-in registry covers the packages you need or if PyPI fallback is reliable for your use case.
- Performance characteristics when querying PyPI for version compatibility on large package lists.
- Accuracy of version compatibility predictions across different OS and CPU architectures.

## Package facts

- License: BSD-3-Clause (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 938.0K/month (top 5,000 on PyPI)
- Known vulnerabilities: none known

## Tags

python package version compatibility, check if package installed, find compatible package version, version resolution python, cross-environment package management, pypi version compatibility, package availability checker, package-management, version-compatibility, dependency-resolution

[View on SkillFed](https://skillfed.io/packages/feu) · [View on PyPI](https://pypi.org/project/feu/)