How do I use a pypi library with modifications in my project properly?

I would like to use a specialized PyPi library with LGPL 3.0 licensing that parses UTF-8 from HTTP Content-Disposition headers properly according to RFC-6266 in my commercial project.

• The repo: https://github.com/g2p/rfc6266
• The PyPi page: https://pypi.org/project/rfc6266/

The problem is that the project only supports Python 3.3, and I use 3.7 in the project. When I use this code with python 3.6 or 3.7 I get warnings.

There are some forks that add support up to 3.6 for the project, and other forks that add other useful functionality.

The maintainer hasn't cut a release in 5 years, so it seems unlikely a PR would be accepted at this point. What are my options to do this in the most legal and Pythonic way?

• Do I use this as a template to write my own library?
• Do I fork the repo, make my changes, and pip install from my own repo?
• Something else?

Thanks Python professionals in advance for your advice.

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