Merge pull request tensorflow#22188 from pengwa:fix_dynamic_rnn_comment

PiperOrigin-RevId: 212469565

tensorflow/python/ops/rnn.py

@@ -709,6 +709,10 @@ def _dynamic_rnn_loop(cell,
   Raises:
     ValueError: If the input depth cannot be inferred via shape inference
       from the inputs.
+    ValueError: If time_step is not the same for all the elements in the
+      inputs.
+    ValueError: If batch_size is not the same for all the elements in the
+      inputs.
   """
   state = initial_state
   assert isinstance(parallel_iterations, int), "parallel_iterations must be int"

tensorflow/python/ops/rnn_cell_impl.py

@@ -954,7 +954,7 @@ def call(self, inputs, state):
     """Run one step of LSTM.
 
     Args:
-      inputs: input Tensor, 2D, `[batch, num_units].
+      inputs: input Tensor, must be 2-D, `[batch, input_size]`.
       state: if `state_is_tuple` is False, this must be a state Tensor,
         `2-D, [batch, state_size]`.  If `state_is_tuple` is True, this must be a
         tuple of state Tensors, both `2-D`, with column sizes `c_state` and