As said, look at abdusammads post too.
Sorry for delay, didn't see that one.
It was python3 and regular pip if I remember correctly.
Regular pip refers to pip2, it may be that you don't have pip3 installed but you could always run python3 and type import pip to test this (although even the most basic Linux distros come with pip3).
Actually some linux distros have it the other way around, pip is symlinked to v3 and you have to type pip2 to use the v2...
He should just use pip3 instead of pip to install the dependencies he thought he installed using pip (but actually pulled the v2 variants).