def get_dir_from_zipfile(zip_file, fallback=None):
    """Return the name of the root folder in a zip file.

    :param zip_file: a :class:`zipfile.ZipFile` instance.
    :param fallback: if `None`, the name of the zip file is used. This is
        returned if the zip file contains more than one top-level directory,
        or none at all.
    """
    fallback = fallback or zip_file.filename
    directories = [name for name in zip_file.namelist() if name.endswith("/")
                   and len(PurePath(name).parts) == 1]
    return fallback if len(directories) > 1 else directories[0]
def test(self):
        # a Structure with a POINTER field
        class S(Structure):
            _fields_ = [("array", POINTER(c_int))]

        s = S()
        # We can assign arrays of the correct type
        s.array = (c_int * 3)(1, 2, 3)
        items = [s.array[i] for i in range(3)]
        self.assertEqual(items, [1, 2, 3])

        # The following are bugs, but are included here because the unittests
        # also describe the current behaviour.
        #
        # This fails with SystemError: bad arg to internal function
        # or with IndexError (with a patch I have)

        s.array[0] = 42

        items = [s.array[i] for i in range(3)]
        self.assertEqual(items, [42, 2, 3])

        s.array[0] = 1