python - Can Pip install dependencies not specified in setup.py at install time?

Question

I'd like pip to install a dependency that I have on GitHub when the user issues the command to install the original software, also from source on GitHub. Neither of these packages are on PyPi (and never will be).

The user issues the command:

pip -e git+https://github.com/Lewisham/cvsanaly@develop#egg=cvsanaly

This repo has a requirements.txt file, with another dependency on GitHub:

-e git+https://github.com/Lewisham/repositoryhandler#egg=repositoryhandler

What I'd like is a single command that a user can issue to install the original package, have pip find the requirements file, then install the dependency too.

Answer 1

This answer helped me solve the same problem you're talking about.

There doesn't seem to be an easy way for setup.py to use the requirements file directly to define its dependencies, but the same information can be put into the setup.py itself.

I have this requirements.txt:

PIL
-e git://github.com/gabrielgrant/django-ckeditor.git#egg=django-ckeditor

But when installing that requirements.txt's containing package, the requirements are ignored by pip.

This setup.py seems to coerce pip into installing the dependencies (including my github version of django-ckeditor):

from setuptools import setup

setup(
    name='django-articles',
    ...,
    install_requires=[
        'PIL',
        'django-ckeditor>=0.9.3',
    ],
    dependency_links = [
        'http://github.com/gabrielgrant/django-ckeditor/tarball/master#egg=django-ckeditor-0.9.3',
    ]
)

Edit:

This answer also contains some useful information.

Specifying the version as part of the "#egg=..." is required to identify which version of the package is available at the link. Note, however, that if you always want to depend on your latest version, you can set the version to dev in install_requires, dependency_links and the other package's setup.py

Edit: using dev as the version isn't a good idea, as per comments below.