Confusion between setup.py's install_requires and requirements.txt

[hickford]

1. http://blog.miguelgrinberg.com/post/the-package-dependency-blues
2. setup.py/install_requires vs requirements.txt packaging.python.org#10
3. https://stackoverflow.com/questions/14399534/how-can-i-reference-requirements-txt-for-the-install-requires-kwarg-in-setuptool

I remember being confused myself. In the end I went with setup.py for my project

Python Packaging User Guide describes the differences, but doesn't so much explain the 'why' http://python-packaging-user-guide.readthedocs.org/en/latest/requirements/

[ncoghlan]

The existing footnote does link out to @dstufft's post at https://caremad.io/2013/07/setup-vs-requirement/ to better cover the "Why?", but there could be a more role-oriented description of that, which is that setup.py is intended for use by library publishers, while requirements.txt is intended for application integrators.

That line gets blurry for web application developers, since they're both the publisher and the integrator.