... virtualenv.

If you're doing more than one project on your machine then you need to concern yourself with dependencies across projects. In python the old-school way of doing this is to use virtualenv and pip. These tools get the job done, but they may have some caveats you should be aware of.


If we want to install fastapi and pandas we can run;

python -m pip install fastapi pandas

To install a specific version we could run;

python -m pip install fastapi==0.50.0

But we can also put our requirements in a file, like so:


Note that pip will install the most recent version of a package unless we tell it not to. In this example we're saying that fastapi needs to be set exactly while numpy needs to be at least version 1.17.

Given such a file, say requirements.txt, then we can also install everything by running;

python -m pip install -r requirements.txt

If you wanted to check which python packages are installed you could run

python -m pip freeze

And if you want to narrow it down you can pipe the output of this command to grep to narrow it down.

python -m pip freeze | grep fastapi

Feedback? See an issue? Something unclear? Feel free to mention it here.

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