Why Python Wheels Matter

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Python wheels (.whl) are the standard, prebuilt distribution format used by pip. Unlike source distributions, wheels are installed without compiling code locally, making them:
  • Faster to install (no build step).
  • More reliable (fewer compiler or dependency failures).
  • Better suited for AI/ML packages, which often include native extensions (C/C++).

On IBM Power, using optimized wheels avoids complex source builds and ensures that the packages are tested and validated for the platform.

Python wheel basics

A wheel file has the extension .whl. A wheel filename is broken down into parts separated by hyphens: 

{dist}-{version}(-{build})?-{python}-{abi}-{platform}.whl
Wheel filename format 
{package}-{version}-{python tag}-{abi tag}-{platform tag}.whl

Each parameter in {brackets} is a tag, or a component of the wheel name that denotes what the wheel contains and on which platform the wheel will work. 

Example:
  numpy-1.26.4-cp310-cp310-manylinux2014_ppc64le.whl

This encodes Python version, ABI, OS, and CPU architecture compatibility.

Types of Wheels

There are three types of wheels, and the wheel’s type is reflected in its filename:

  • Universal wheel: Contains py2.py3-none-any.whl. Supports both Python 2 and Python 3 on any OS and platform. Most wheels listed on the Python Wheels website are universal wheels.
  • Pure Python wheel: Contains either py3-none-any.whl or py2-none-any.whl. Supports either Python 3 or Python 2, but not both. It is like the universal wheel, but labeled with either py2 or py3 instead of py2.py3.
  • Platform wheel: Supports only a specific Python version and platform. Contains segments indicating a specific Python version, ABI, operating system, or architecture. Common for AI/ML and numerical libraries. 
    Example: 
  cp312-cp312-manylinux_2_34_ppc64le.whl