Prevent Accidental Installation of Packages Outside Virtual Environment

You may often find yourself accidentally installing packages to your global python interpreter because you forgot to activate a virtual environment. Thankfully you can make pip require virtualenv to be activated in order to perform the install.

There are two ways to do this: either by using an environment variable PIP_REQUIRE_VIRTUALENV or by enabling require-virtualenv pip config option.

To make this a default globally either add the following to your .bashrc (or .zshrc or whatever other rc you are using)

echo "export PIP_REQUIRE_VIRTUALENV=true" >> ~/.bashrc

or run the following command

python -m pip config set global.require-virtualenv true

Which will add something along the lines of

[global]
require-virtualenv = true

to your ~/.config/pip/pip.conf (may be a different location on your system).

I prefer the second option as that way I don't clutter my .bashrc and if I add new pip config entries they will all be in the same file. The second option also works on Windows.

---

Setting this option globally will be useful most of the time but you may still need to run commands for the global interpreter.

$ pip freeze
ERROR: Could not find an activated virtualenv (required).

This can be easily achieved by adding PIP_REQUIRE_VIRTUALENV=false in front of the command that's failing:

$ PIP_REQUIRE_VIRTUALENV=false pip freeze