The https://bitbucket.org/cliff/cpython#python24258 URL 404's

Looking at the attached bz2.py diff, I would change:

         if isinstance(filename, (str, bytes, os.PathLike)):
             self._fp = _builtin_open(filename, mode)
+            self.filename = filename
             self._closefp = True
             self._mode = mode_code

to special-case os.PathLike and do:

            self.filename = str(filename)

I would expect BZ2File.name to be a string.   Returning a PathLike means lots of legitimate string methods will not work on it.  Also, it should be "name" as an attribute, not "name()" as a method, to match other existing interfaces.