code: def devices(self):
          
          devices = []
          count = self.lib.tdGetNumberOfDevices()
          for i in range(count):
              device = DeviceFactory(self.lib.tdGetDeviceId(i), lib=self.lib)
              devices.append(device)
          return devices
docs: Return all known devices.
  
          :return: list of :class:`Device` or :class:`DeviceGroup` instances.