diff --git a/egs/librispeech/ASR/tdnn_lstm_ctc/asr_datamodule.py b/egs/librispeech/ASR/tdnn_lstm_ctc/asr_datamodule.py
index 732a842ad..91c1d6a96 100644
--- a/egs/librispeech/ASR/tdnn_lstm_ctc/asr_datamodule.py
+++ b/egs/librispeech/ASR/tdnn_lstm_ctc/asr_datamodule.py
@@ -1,4 +1,4 @@
-# Copyright      2021  Xiaomi Corp.        (authors: Fangjun Kuang)
+# Copyright      2021  Piotr Żelasko
 #
 # See ../../../../LICENSE for clarification regarding multiple authors
 #
diff --git a/egs/yesno/ASR/local/compute_fbank_yesno.py b/egs/yesno/ASR/local/compute_fbank_yesno.py
index a11a3185d..dad7319fd 100755
--- a/egs/yesno/ASR/local/compute_fbank_yesno.py
+++ b/egs/yesno/ASR/local/compute_fbank_yesno.py
@@ -17,8 +17,9 @@ from lhotse.recipes.utils import read_manifests_if_cached
 
 from icefall.utils import get_executor
 
-# Torch's multithreaded behavior needs to be disabled or it wastes a lot of CPU and
-# slow things down.  Do this outside of main() in case it needs to take effect
+# Torch's multithreaded behavior needs to be disabled or it wastes a
+# lot of CPU and slow things down.
+# Do this outside of main() in case it needs to take effect
 # even when we are not invoking the main (e.g. when spawning subprocesses).
 torch.set_num_threads(1)
 torch.set_num_interop_threads(1)
diff --git a/egs/yesno/ASR/tdnn/asr_datamodule.py b/egs/yesno/ASR/tdnn/asr_datamodule.py
index 141d34f93..8b2b44c8a 100644
--- a/egs/yesno/ASR/tdnn/asr_datamodule.py
+++ b/egs/yesno/ASR/tdnn/asr_datamodule.py
@@ -1,14 +1,29 @@
+# Copyright      2021  Piotr Żelasko
+#                2021  Xiaomi Corp.        (authors: Fangjun Kuang)
+#
+# See ../../../../LICENSE for clarification regarding multiple authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 import argparse
 import logging
 from functools import lru_cache
 from pathlib import Path
-from typing import List, Union
+from typing import List
 
 from lhotse import CutSet, Fbank, FbankConfig, load_manifest
 from lhotse.dataset import (
     BucketingSampler,
     CutConcatenate,
-    CutMix,
     K2SpeechRecognitionDataset,
     PrecomputedFeatures,
     SingleCutSampler,
diff --git a/egs/yesno/ASR/tdnn/decode.py b/egs/yesno/ASR/tdnn/decode.py
index a3df0a632..a87219010 100755
--- a/egs/yesno/ASR/tdnn/decode.py
+++ b/egs/yesno/ASR/tdnn/decode.py
@@ -3,9 +3,8 @@
 
 import argparse
 import logging
-from collections import defaultdict
 from pathlib import Path
-from typing import Dict, List, Optional, Tuple
+from typing import List, Tuple
 
 import k2
 import torch
@@ -14,13 +13,7 @@ from asr_datamodule import YesNoAsrDataModule
 from model import Tdnn
 
 from icefall.checkpoint import average_checkpoints, load_checkpoint
-from icefall.decode import (
-    get_lattice,
-    nbest_decoding,
-    one_best_decoding,
-    rescore_with_n_best_list,
-    rescore_with_whole_lattice,
-)
+from icefall.decode import get_lattice, one_best_decoding
 from icefall.lexicon import Lexicon
 from icefall.utils import (
     AttributeDict,
@@ -243,7 +236,7 @@ def save_results(
     # ref/hyp pairs.
     errs_filename = exp_dir / f"errs-{test_set_name}.txt"
     with open(errs_filename, "w") as f:
-        wer = write_error_stats(f, f"{test_set_name}", results)
+        write_error_stats(f, f"{test_set_name}", results)
 
     logging.info("Wrote detailed error stats to {}".format(errs_filename))
 
diff --git a/egs/yesno/ASR/tdnn/train.py b/egs/yesno/ASR/tdnn/train.py
index 603085fcd..a5a248c9c 100755
--- a/egs/yesno/ASR/tdnn/train.py
+++ b/egs/yesno/ASR/tdnn/train.py
@@ -17,7 +17,6 @@ from lhotse.utils import fix_random_seed
 from model import Tdnn
 from torch.nn.parallel import DistributedDataParallel as DDP
 from torch.nn.utils import clip_grad_norm_
-from torch.optim.lr_scheduler import StepLR
 from torch.utils.tensorboard import SummaryWriter
 
 from icefall.checkpoint import load_checkpoint
diff --git a/icefall/dataset/datamodule.py b/icefall/dataset/datamodule.py
index 97767ef9d..97918ffd8 100644
--- a/icefall/dataset/datamodule.py
+++ b/icefall/dataset/datamodule.py
@@ -1,4 +1,4 @@
-# Copyright      2021  Xiaomi Corp.        (authors: Fangjun Kuang)
+# Copyright      2021  Piotr Żelasko
 #
 # See ../../LICENSE for clarification regarding multiple authors
 #