code: def container_instance_from_string(id):
      
      try:
          service, instance = id.rsplit('_', 1)
          instance = int(instance)
      except (TypeError, ValueError):
          raise context.ValueError("Invalid container id %r" % id)
      return _proto.ContainerInstance(service_name=service, instance=instance)
docs: Create a ContainerInstance from an id string