PPDataset: be strict about seq_order and seq_list in `init_seq_…

…order` (#1652)

returnn/datasets/postprocessing.py

@@ -127,6 +127,7 @@ def __init__(
         self._map_seq_stream = map_seq_stream
         self._map_outputs = map_outputs
         self._rng = RandomState(self._get_random_seed_for_epoch(0))
+        self._seq_list_for_validation: Optional[List[str]] = None
 
         self._dataset = init_dataset(self._dataset_def, parent_dataset=self)
         if self._map_seq_stream is None:
@@ -169,6 +170,12 @@ def init_seq_order(
         """
         super().init_seq_order(epoch=epoch, seq_list=seq_list, seq_order=seq_order)
 
+        if self._map_seq_stream is not None:
+            if seq_list is not None:
+                raise ValueError("map_seq_stream is set, cannot specify custom seq_list")
+            if seq_order is not None:
+                raise ValueError("map_seq_stream is set, cannot specify custom seq_order")
+
         if epoch is None and seq_list is None and seq_order is None:
             self._num_seqs = 0
             return True
@@ -177,6 +184,7 @@ def init_seq_order(
         assert self._dataset is not None
         self._dataset.init_seq_order(epoch=epoch, seq_list=seq_list, seq_order=seq_order)
         self._data_iter = enumerate(self._build_mapping_iter())
+        self._seq_list_for_validation = seq_list
         if self._map_seq_stream is None:
             # If we don't have an iterable mapper we know the number of segments exactly
             # equals the number of segments in the wrapped dataset
@@ -260,7 +268,8 @@ def _iterate_dataset(self) -> Iterator[TensorDict]:
             tensor_dict = self._in_tensor_dict_template.copy_template()
             for data_key in data_keys:
                 tensor_dict.data[data_key].raw_tensor = self._dataset.get_data(seq_index, data_key)
-            tensor_dict.data["seq_tag"].raw_tensor = str_to_numpy_array(self._dataset.get_tag(seq_index))
+            seq_tag_tensor = str_to_numpy_array(self._dataset.get_tag(seq_index))
+            tensor_dict.data["seq_tag"].raw_tensor = seq_tag_tensor
 
             if self._map_seq is not None:
                 tensor_dict = self._map_seq(
@@ -273,7 +282,14 @@ def _iterate_dataset(self) -> Iterator[TensorDict]:
                 # Re-adding the seq tag here causes no harm in case it's dropped since we don't
                 # add/drop any segments w/ the non-iterator postprocessing function.
                 if "seq_tag" not in tensor_dict.data:
-                    tensor_dict.data["seq_tag"].raw_tensor = str_to_numpy_array(self._dataset.get_tag(seq_index))
+                    tensor_dict.data["seq_tag"].raw_tensor = seq_tag_tensor
+
+                if self._seq_list_for_validation is not None:
+                    seq_tag = self._seq_list_for_validation[seq_index]
+                    tag_of_seq = tensor_dict.data["seq_tag"].raw_tensor.item()
+                    assert (
+                        tag_of_seq == seq_tag
+                    ), f"seq tag mismath: {tag_of_seq} != {seq_tag} for seq index {seq_index} when seq list is given"
 
             yield tensor_dict
             seq_index += 1