PIP error after upgraded to v10.0.1

After doing a PIP upgrade:

sudo pip install --upgrade pip

I got this error when running PIP:

Traceback (most recent call last):
  File "/usr/bin/pip", line 9, in <module>
    from pip import main
ImportError: cannot import name main

Here is the best way to fix that, clearing the hash in bash:

hash -d pip

or in dash (sh):

hash -r pip

The world is fine now.