Optional dependencies in a pip requirements file

python dependencies pip pypi
del picture del · Sep 8, 2010 · Viewed 19.5k times · Source

How can I specify optional dependencies in a pip requirements file?

According to the pip documentation this is possible, but the documentation doesn't explain how to do it, and I can't find any examples on the web.

Answer

Daniel Naab picture Daniel Naab · Sep 8, 2010

Instead of specifying optional dependencies in the same file as the hard requirements, you can create a optional-requirements.txt and a requirements.txt.

To export your current environment's packages into a text file, you can do this:

pip freeze > requirements.txt

If necessary, modify the contents of the requirements.txt to accurately represent your project's dependencies. Then, to install all the packages in this file, run:

pip install -U -r requirements.txt

-U tells pip to upgrade packages to the latest version, and -r tells it to install all packages in requirements.txt.

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