/opt/eff.org/certbot/venv/bin/python: No module named pip.__main__; 'pip' is a package and cannot be directly executed

 I encountered this error while trying to renew Let's Encrypt Certbot-Auto

/opt/eff.org/certbot/venv/bin/python: No module named pip.__main__; 'pip' is a package and cannot be directly executed

My webserver is using Ubuntu 12.04.3 LTS (precise).

My certbot-auto is located at /data_local/app/cron_shell/lets_encrypt   (yours will be different)

I searched for a solution for 2 hours before finding this one that worked:

STEP 1 - MAKE COPY OF EXISTING CERTBOT-AUTO

cp /data_local/app/cron_shell/lets_encrypt/certbot-auto /data_local/app/cron_shell/lets_encrypt/certbot-auto-20201114

STEP 2 - EDIT THE CONTENTS OF CERTBOT-AUTO

    pip_version = StrictVersion(check_output([python, '-m', 'pip', '--version'])

        TO

    pip_version = StrictVersion(check_output(['pip', '--version'])

- and -

    command = [python, '-m', 'pip', 'install', '--no-index', '--no-deps', '-U']

        TO

    command = ['pip', 'install', '--no-index', '--no-deps', '-U']

STEP 3 - RETRY TO UPGRADE CERTBOT-AUTO
(a regular renew action without -no-upgrade will automatically do upgrade)

/data_local/app/cron_shell/lets_encrypt/certbot-auto renew