running a python script with virtualenv on NixOs

I am not a python developer. But what I know that newer packages tend to use requirements.txt to declare their dependencies.

For python packages that are not part of nixpkgs, I found the easiest to way to run them typically is to use virtualenv. Which as I understand it, is the python way to install a project’s dependencies in a contained way and not pollute your global environment.

If the project happens to have a requirements.txt. I found that the process is pretty straightforward. Just follow the section from the nixos python wiki page about (using virtualenv) [https://nixos.wiki/wiki/Python].

python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

If the project has a setup.py run that as well

python setup.py install

When you need to use these packages, just drop into the virtualenv of the project and you’ll have access to it source <path_to_your_project>/.venv/bin/activate then run the setup script again. 🤷