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_nested_initializers(self):
        # test initializing nested structures
        class Phone(Structure):
            _fields_ = [("areacode", c_char*6),
                        ("number", c_char*12)]

        class Person(Structure):
            _fields_ = [("name", c_char * 12),
                        ("phone", Phone),
                        ("age", c_int)]

        p = Person(b"Someone", (b"1234", b"5678"), 5)

        self.assertEqual(p.name, b"Someone")
        self.assertEqual(p.phone.areacode, b"1234")
        self.assertEqual(p.phone.number, b"5678")
        self.assertEqual(p.age, 5)