I wanted to create a subclass of VersionInfo for company reasons (more checkings, more methods, etc) and it turned out the VersionInfo.parse is a staticmethod, always returning VersionInfo instances, no matter what.

By turning the parse static method into a class method and making it return cls(**version_parts) the result of parse will be an instance of the subclass (my class), not the superclass (VersionInfo).

e.g:

class MyBogusVersionInfo(semver.VersionInfo):

    @classmethod
    def parse(cls, version):
        if version.startswith("foobar"):
            version = version[6:]
        return super().parse(version)

print(type(MyBogusVersionInfo.parse("1.2.3")))

Current result is : <class 'semver.VersionInfo'>, while I would have expected <class 'MyBogusVersionInfo'>