Python setuptools exclude dependencies when installing

Question

Python setuptools allows you to specify optional dependencies, but does it allow you to do something in the inverse?

For example, let's say I have a list of dependencies in my_package like below:

• numpy
• pandas

So if I installed the package with pip install my_package, it would also install these two dependencies.

However, for certain use cases, a user may not need pandas. So I would want to do something like pip install my_package[~pandas] or something like that to instruct pip to not install pandas.

Is this something that is currently supported?

Answer 1

It is not currently supported - extras are strictly additive. It has been proposed several times, but the discussions never seem to get anywhere.

The latest discussion is here:

Proposal - expanding optional dependencies to support opt-out of recommended/default installables.

As a workaround, you can use:

pip install --no-deps my_package

But this would exclude every dependency, including pandas. You'd have to find and install the other dependencies manually.

Answer 2

As you mentioned, while it is possible to install optional dependencies with, for example

pip install my_package[super,cool]

the opposite, keeping from installing dependencies (!cool) is not possible. Wim already mentioned the --no-deps workaround. Another workaround might be to provide two versions, my_package and my_package_vanilla with different dependencies. Then user could install, for example:

• my_package to install all default dependencies needed by the average user
• my_package_vanilla to install just the bare bones version of my_package (perhaps even non-functional without extras?)
• my_package_vanilla[pandas,super,cool] installing three sets of extra dependencies chosen by the user.