Wheel files in python

20-05-2025

Introduced in PEP 427:

• https://peps.python.org/pep-0427/
• https://pypi.org/project/wheel/

What are wheel files:

• built distribution which replaces the egg format (ready-to-install)
• {dist}-{version}(-{build})?-{python}-{abi}-{platform}.whl
  • example = cryptography-2.9.2-cp35-abi3-macosx_10_9_x86_64.whl
  • version = https://peps.python.org/pep-0440/
  • python = https://peps.python.org/pep-0425/
  • abi = https://docs.python.org/3/c-api/stable.html
  • platform = OS / OS tools needed for compilation / instruction set architecture
• ZIP-format archive, .whl file extension, containing a single distribution, may be unpacked directly into site-packages

Benefits:

• smaller in size
• allows for faster installation for pure python and native C extension packages
• avoids arbitrary code execution for installation
  • everything is run inside setup.py when using sdist
• more consistent installs across platforms and machines
  • does not require a compiler for C extensions
  • pip generates .pyc files in the wheel that match the right interpreter

Types of wheels:

• universal wheel (python 2 AND python 3 AND any OS)
• pure-python wheel (python 2 OR python 3)
• platform wheel ([python 2 or python 3] AND platform)

Tools to build wheels for all:

• https://github.com/pypa/cibuildwheel
• https://github.com/multi-build/multibuild
• https://github.com/pypa/auditwheel - bundle external libraries into wheels