How can I specify a python version using setuptools?

Is there a way to specify a python version to be used with a python package defined in setup.py?

My setup.py currently looks like this:

from distutils.core import setup
setup(
  name = 'macroetym',
  packages = ['macroetym'], # this must be the same as the name above
  version = '0.1',
  description = 'A tool for macro-etymological textual analysis.',
  author = 'Jonathan Reeve',
  author_email = '[email protected]',
  url = 'https://github.com/JonathanReeve/macro-etym', 

  download_url = 'https://github.com/JonathanReeve/macro-etym/tarball/0.1', # FIXME: make a git tag and confirm that this link works
  install_requires = ['Click', 'nltk', 'pycountry', 'pandas',
                      'matplotlib'],
  include_package_data = True,
  package_data = {'macroetym': ['etymwm-smaller.tsv']}, 
  keywords = ['nlp', 'text-analysis', 'etymology'], 
  classifiers = [],
  entry_points='''
      [console_scripts]
      macroetym = macroetym.main:cli
  ''',
)

It's a command-line program. My script runs using Python 3, but a lot of operating systems still have Python 2 as the default. How can I specify a python version to be used here? I can't seem to find anything in the docs, but maybe I'm not looking in the right place?

Solution

With newer versions of setuptools (24.2.0 or above) and newer versions of pip (9.0.0 or above) you can use python_requires: https://packaging.python.org/tutorials/distributing-packages/#python-requires

Python 3+:

python_requires='>=3',

If your package is for Python 3.3 and up but you’re not willing to commit to Python 4 support yet, write:

python_requires='~=3.3',

If your package is for Python 2.6, 2.7, and all versions of Python 3 starting with 3.3, write:

python_requires='>=2.6, !=3.0.*, !=3.1.*, !=3.2.*, <4',

For older versions the old answer/workaround.

You can raise an error or warning using sys.version or platform.python_version()

import sys
print(sys.version)
print(sys.version_info)
print(sys.version_info.major)  # Returns 3 for Python 3

Or:

import platform
print(platform.python_version())