Graph 为什么tf2可以'；是否将tf_函数模型保存为.pb文件？

我试图保存一个模型，如transformer on的官方代码，但当我想使用tf.summary.trace_on保存列车运行图或跟踪时，它会出错。错误如下

    ---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
/usr/local/lib/python3.6/dist-packages/tensorflow_core/python/framework/func_graph.py in convert(x)
    936         try:
--> 937           x = ops.convert_to_tensor_or_composite(x)
    938         except (ValueError, TypeError):

15 frames
TypeError: Can't convert Operation 'PartitionedFunctionCall' to Tensor (target dtype=None, name=None, as_ref=False)

During handling of the above exception, another exception occurred:

TypeError                                 Traceback (most recent call last)
/usr/local/lib/python3.6/dist-packages/tensorflow_core/python/framework/func_graph.py in convert(x)
    941               "must return zero or more Tensors; in compilation of %s, found "
    942               "return value of type %s, which is not a Tensor." %
--> 943               (str(python_func), type(x)))
    944       if add_control_dependencies:
    945         x = deps_ctx.mark_as_return(x)

TypeError: To be compatible with tf.contrib.eager.defun, Python functions must return zero or more Tensors; in compilation of <function canonicalize_signatures.<locals>.signature_wrapper at 0x7fcf794b47b8>, found return value of type <class 'tensorflow.python.framework.ops.Operation'>, which is not a Tensor.

---

错误按设想发生。但是我怎样才能修复它呢？位置编码需要，我不知道如何替换此操作。

我计算它是因为我没有在pb文件中保存变压器模型。

我计算它是因为我没有在pb文件中保存变压器模型

    import tensorflow as tf
sig=[tf.TensorSpec(shape=(None, None), dtype=tf.int64),tf.TensorSpec(shape=(None, None), dtype=tf.int64)]
@tf.function(input_signature=sig)
def cal(a,d):
  b=a[1:]
root=tf.Module()
root.func = cal

# 获取具体函数。
concrete_func = root.func.get_concrete_function(
      tf.TensorSpec(shape=(None, None), dtype=tf.int64),tf.TensorSpec(shape=(None, None), dtype=tf.int64)
)
tf.saved_model.save(root, '/correct', concrete_func)