PyPI
By the Python Software Foundation
PyPI (the Python Package Index) is the official public repository of software packages for the Python programming language, used by the pip package installer to find and download libraries.
Definition
PyPI (the Python Package Index) is the official public repository of software packages for the Python programming language, used by the pip package installer to find and download libraries.
Overview
PyPI hosts hundreds of thousands of Python packages, from small utility libraries to major frameworks, that developers install with `pip install <package>`. Package authors upload releases to PyPI along with metadata such as version number, license, and dependencies, and pip resolves a project's declared requirements against what is available on the index, similar in role to how the npm Registry serves the JavaScript ecosystem. Because pip installs packages directly from PyPI by default, Python projects commonly pin dependency versions in a requirements file or lockfile to keep builds reproducible, and many teams isolate dependencies per project using tools like venv or Poetry to avoid version conflicts between projects. Organizations with stricter security or availability requirements sometimes proxy or mirror PyPI through an internal artifact repository manager such as Nexus Repository or JFrog Artifactory.
Key Features
- Public index of hundreds of thousands of Python packages
- Simple installation via the pip command-line tool
- Package metadata including version, license, and dependencies
- Support for pre-release and development release versions
- API used by tooling for dependency resolution and vulnerability checks
- TestPyPI as a separate index for testing package publishing