And remember that if you're not adding any installation options or doing it in a virtual environment you need to run sudo pip install drm4g.
When installing with pip, I get a SNIMissingWarning or InsecurePlatformWarning
The problems you're having are related with your versions of python and your virtual environment. They can be ignored since they don't affect the installation process.
One solution for solving the SNIMissingWarning and InsecurePlatformWarning warnings is to upgrade to a more recent version of Python.
If for any reason you are not able to upgrade, you can also run pip install 'requests[security]' as explained ?here.