pip: no module named _internal

Question

I have a problem when I try to use pip in any way. I\'m using Ubuntu 16.04.4

I should say that I\'ve used it already, and I never had any problem, but starting today

Answer 1

I just encountered the same problem and in my case, it turns out this is a conflict between the python installation in my virtualenv and the site-wide python (Ubuntu). What solves it for me is to run pip in this way, to force usage of the correct python installation (in my vortualenv):

python3 -m pip install PACKAGE

instead of

pip3 install PACKAGE

I realised this when I tried to follow some of the answers here that suggest re-installing pip and the error output I got was pointing to an existing site-wide python library path although I had activated my virtualenv. Worth trying before deleting and re-installing stuff.