Setuptools platform specific dependencies

Question

Is there any way to tell setuptools or distribute to require a package on a specific platform?

In my specific case, I\'m using readline, which comes as par

Answer 1

Other answers are valid and probably more convenient if supporting old setuptools versions is required, but there have been some advancements:

Recent versions of setuptools accept PEP 508 style dependency specification:

setup(
    # ...
    install_requires=[
        'pyreadline; platform_system == "Windows"',
    ],
)

Choose the right parameter:

• install_requires: what other distributions are needed for the current distribution to work correctly
• extras_require: a dictionary mapping the names of optional features to a list of their requirements
• setup_requires: other distributions that need to be present for the setup script to run correctly Note: projects listed in setup_requires will NOT be automatically installed. They are simply downloaded to the ./.eggs directory if they’re not locally available already.

There is also an alternative way for supplying these parameters through setup.cfg file. See the documentation for more info.

PEP 518 introduces a new and more capable way of specifying setup_requires in pyproject.toml file:

[build-system]
# Minimum requirements for the build system to execute.
requires = ['setuptools>"38.3.0"', 'wheel']  # PEP 508 specifications.

The feature was implemented in pip 10.0.0b1. Using it one will be able to automatically install and update build system requirements.