Enforcing python version in setup.py

Question

Currently, we are setting\installing up some packages on system by mentioning their version and dependencies in setup.py under install_requires attribute. Our system requires Python 2.7. Sometimes, users are having multiple versions of Python on their systems, say 2.6.x and 2.7, some packages it says are available already but actually on the system available under 2.6 site packages list. Also some users have 2.6 only, how to enforce from setup.py or is there any other way to say to have only Python 2.7 and all packages which we want setup.py to update are for only 2.7. We require minimum 2.7 on the machine to run our code.

Answer 1

The current best practice (as of this writing in March 2018) is to add a python_requires argument directly to the setup() call in setup.py:

from setuptools import setup

[...]

setup(name="my_package_name",
      python_requires='>3.5.2',
      [...]

Note that this requires setuptools>=24.2.0 and pip>=9.0.0; see the documentation for more information.

Answer 2

As the setup.py file is installed via pip (and pip itself is run by the python interpreter) it is not possible to specify which Python version to use in the setup.py file.

Instead have a look at this answer to setup.py: restrict the allowable version of the python interpreter which has a basic workaround to stop the install.

In your case the code would be:

import sys
if sys.version_info < (2,7):
    sys.exit('Sorry, Python < 2.7 is not supported')