How can I specify library versions in setup.py?

In my setup.py file, I've specified a few libraries needed to run my project:

setup(
    # ...
    install_requires = [
        'django-pipeline',
        'south'
    ]
)

How can I specify required versions of these libraries?

I'm not sure about buildout, however, for setuptools/distribute, you specify version info with the comparison operators (like ==, >=, or <=).

For example:

install_requires = ['django-pipeline==1.1.22', 'south>=0.7']

You can add them to your requirements.txt file along with the version.

For example:

django-pipeline==1.1.22
south>=0.7

and then in your setup.py

import os
from setuptools import setup

with open('requirements.txt') as f:
    required = f.read().splitlines()

setup(...
install_requires=required,
...)

Reading from the docs -

It is not considered best practice to use install_requires to pin dependencies to specific versions, or to specify sub-dependencies (i.e. dependencies of your dependencies). This is overly-restrictive, and prevents the user from gaining the benefit of dependency upgrades.

https://packaging.python.org/discussions/install-requires-vs-requirements/#id5