wheel / README.txt


A built-package format for Python.

A wheel is a ZIP-format archive with a specially formatted filename
and the .whl extension. It is designed to contain all the files for a
PEP 376 compatible install in a way that is very close to the on-disk
format. Many packages will be properly installed with only the "Unpack"
step (simply extracting the file onto sys.path), and the unpacked archive
preserves enough information to "Spread" (copy data and scripts to their
final locations) at any later time.

The wheel project provides a `bdist_wheel` command for setuptools
(requires setuptools >= 0.8.0). Wheel files can be installed with a
newer `pip` from or with wheel's own command
line utility.

The wheel documentation is at The file format
is documented in PEP 427 (

The reference implementation is at

Why not egg?

Python's egg format predates the packaging related standards we have
today, the most important being PEP 376 "Database of Installed Python
Distributions" which specifies the .dist-info directory (instead of
.egg-info) and PEP 426 "Metadata for Python Software Packages 2.0"
which specifies how to express dependencies (instead of requires.txt
in .egg-info).

Wheel implements these things. It also provides a richer file naming
convention that communicates the Python implementation and ABI as well
as simply the language version used in a particular package.

Unlike .egg, wheel will be a fully-documented standard at the binary
level that is truly easy to install even if you do not want to use the
reference implementation.