Install pip

In some cases, it may appear that Blender's python already knows about your system's installation of python (python is usually installed by default on most Linux distros). In such cases, you may use just pip install something to install libraries.

There are two known ways to install pip into Blender.

Option 1

This I tested on latest Blender 2.81 builds. The similar instructions should work for other Blender 2.8x versions.

$ /path/to/blender/2.xx/python/bin/python3 -m ensurepip
$ /path/to/blender/2.xx/python/bin/python3 -m pip install --upgrade pip setuptools wheel

(exact name of python executable depends on specific blender build).

Option 2

If, for some reason, Option 1 does not work for you (on some system Python says no module named ensurepip), then you have to do the following:

1. Download get-pip.py script

2. Run it with Blender's python:

   $ /path/to/blender/2.xx/python/bin/python3.7m /path/to/get-pip.py

Please refer to official pip site for official installation instructions.