Python - cant find pip.ini or pip.conf in Windows

Instead of checking a list of well-known locations, you can ask pip to list the valid locations:

pip config -v list

Fun fact

On the same machine, with the same pip version, the valid locations can vary based on the actual Python version.

Environment: Win 7 x64, the HOME environment variable is set to D:\Home

Python 3.7.3:

> pip config -v list
For variant 'global', will try loading 'C:\ProgramData\pip\pip.ini'
For variant 'user', will try loading 'D:\Home\pip\pip.ini'
For variant 'user', will try loading 'C:\Users\foobar\AppData\Roaming\pip\pip.ini'
For variant 'site', will try loading 'C:\Python37\pip.ini'

Python 3.8.0:

> pip config -v list
For variant 'global', will try loading 'C:\ProgramData\pip\pip.ini'
For variant 'user', will try loading 'C:\Users\foobar\pip\pip.ini'
For variant 'user', will try loading 'C:\Users\foobar\AppData\Roaming\pip\pip.ini'
For variant 'site', will try loading 'C:\Python38\pip.ini'

Finally got it sorted.

Apparently for Windows users pip.ini config file is not created, however can be added manually!

just create new %APPDATA%\pip\pip.ini and content of custom repository:

[install]
find-links = https://<login>:<password>@your.repo.com/custom/url

Reference: https://pip.pypa.io/en/stable/user_guide/#config-file