pip error - cannot import main [SOLVED] + module has no attribute SSL_ST_INIT

Set python2.7 as default:

sudo update-alternatives --config python

select python2.7

Remove pip:

sudo python -m pip uninstall pip
sudo apt purge --autoremove python-pip

Reinstall it:

sudo apt install python-pip

Check the pip --version:

pip 9.0.1 from /usr/lib/python2.7/dist-packages (python 2.7)

Do not upgrade pip to the latest version.

In case of the following error:
AttributeError: 'module' object has no attribute 'SSL_ST_INIT'

sudo python -m easy_install --upgrade pyOpenSSL