Yesterday, I have fixed an issue in bpo and this issue was for the support of os.PathLike in FileCookieJar. Since the introduction of os.PathLike and __fspath__, we continue to convert some parts of code to be os.PathLike compliant and I think there is a pattern for that.

Maybe we could create a page "Patterns" with some examples.

For example (but need to be tested and approved)

How to support a os.PathLike object?

def __init__(self, filename):
    try:
        filename = os.fspath(filename)
    except TypeError:
        raise ValueError("filename must be a string-like or path-like object")