Since self.connect() is always called, you should document that the initial hkey parameter has to be one of the following predefined key handles:
HKEY_LOCAL_MACHINE HKEY_USERS HKEY_PERFORMANCE_DATA WinAPI RegConnectRegistryW() only matters when the target computer is a different machine, in which case an RPC proxy handle is returned. -- https://mail.python.org/mailman/listinfo/python-list