error，请教您一下这个问题

[yudadabing]

4285
1072
Traceback (most recent call last):
File "Train_number.py", line 36, in
images, labels = dataiter.next()
File "D:\Anconda\envs\pytorch_env\lib\site-packages\torch\utils\data\dataloader.py", line 346, in next
data = self.dataset_fetcher.fetch(index) # may raise StopIteration
File "D:\Anconda\envs\pytorch_env\lib\site-packages\torch\utils\data_utils\fetch.py", line 44, in fetch
data = [self.dataset[idx] for idx in possibly_batched_index]
File "D:\Anconda\envs\pytorch_env\lib\site-packages\torch\utils\data_utils\fetch.py", line 44, in
data = [self.dataset[idx] for idx in possibly_batched_index]
File "C:\Users\yudadabing\Desktop\License-Plate-Detection-and-Recognition-master\License-Plate-Detection-and-Recognition-master\dataload.py", line 78, in getitem
label = int(path_list[-2])
ValueError: invalid literal for int() with base 10: 'num_letter'

[yudadabing]

ValueError: invalid literal for int() with base 10: 'data/train_images/training-set/num_letter/12'

[yudadabing]

4285
1072
tensor([24, 10, 20, 31])
Traceback (most recent call last):
File "Train_number.py", line 54, in
for i, data in enumerate(trainloader, 0):
File "D:\Anconda\envs\pytorch_env\lib\site-packages\torch\utils\data\dataloader.py", line 346, in next
data = self.dataset_fetcher.fetch(index) # may raise StopIteration
File "D:\Anconda\envs\pytorch_env\lib\site-packages\torch\utils\data_utils\fetch.py", line 44, in fetch
data = [self.dataset[idx] for idx in possibly_batched_index]
File "D:\Anconda\envs\pytorch_env\lib\site-packages\torch\utils\data_utils\fetch.py", line 44, in
data = [self.dataset[idx] for idx in possibly_batched_index]
File "C:\Users\yudadabing\Desktop\陈晨师兄车牌识别\License-Plate-Detection-and-Recognition-master\License-Plate-Detection-and-Recognition-master\dataload.py", line 71, in getitem
if img[i, j] < 0:
TypeError: 'NoneType' object is not subscriptable