op_builders.py 文件源码

def build_step(self, signals):
        time = signals.time if self.time_input else []
        inputs = ([] if self.input_data is None
                  else signals.gather(self.input_data))

        with tf.device("/cpu:0"):
            node_outputs = tf.py_func(
                self.merged_func, [time, inputs], self.output_dtype,
                name=self.merged_func.__name__)
        node_outputs.set_shape(self.output_shape)

        if self.output_data is not None:
            signals.scatter(self.output_data, node_outputs)

        # note: we only need to run the node for side effects, not the
        # assignment operator. if the result of the assignment is actually
        # used anywhere, then it will be run as part of the normal graph.
        return node_outputs