Downstream issue: python/cpython#100609

str(zipp.Path(...)) currently raises TypeError if the ZipFile object is initialised with a fileobj rather than a path. Given that object.__str__() doesn't raise, I think it's a bug that zipp.Path.__str__() does.

(Other zipp.Path attributes like filename, name and parent have the same behaviour, but they're not attributes of object, so it's less of an issue)

There's at least two possible solutions:

1. Use a ":fileobj:" prefix for fileobj-backed zip files
2. Use self.at with no prefix in all cases