Python typing 模块，ByteString() 实例源码

def __setitem__(self, key: ByteString, value: ByteString) -> None:
        raise NotImplementedError  # pragma: no cover

def get(self, key: ByteString, default=None) -> Union[bytes, None]:
        raise NotImplementedError  # pragma: no cover

def test_string_types(create_project, run, type_, expected):
    """Test type hinting with string types."""
    with create_project('''
        from typing import Any, AnyStr, ByteString

        def types(value):
            # type: ({type}) -> Any
            """usage: say types <value>"""
            print(type(value))
    '''.format(type=type_)):
        assert run('say types abc').strip().split('\n') == [repr(expected)]

def sign_message(body: ByteString, secret: Text) -> Text:
    """
    Compute a message's signature.
    """

    return 'sha1={}'.format(
        hmac.new(secret.encode(), body, sha1).hexdigest()
    )

def read(self) -> ByteString:
        return json.dumps(self.response).encode()