AttributeError: 'tuple' object has no attribute 'size'

Hi, I am working on omniglot images and I am struggling with this error. I believe the problem is with my dataset generation. Please help me figure it out. Here is the dataset code:

import os
from PIL import Image
import numpy as np
from import Dataset
import torch
from torchvision import datasets, transforms
class Dataset(Dataset):
    def __init__(self,data_txt,transformm):
        location_file = open(data_txt, 'r')
        locations =
        self.filenames = locations
        self.labels = []
        self.images = []
        self.transform = transformm
        self.path = os.getcwd()
        for address in locations:
            #label creation
            label = address.split('/')[0]

    def __len__(self):
        return len(self.filenames)

    def __getitem__(self, idx):
        image =,'images_background', self.filenames[idx]))
        image = self.transform(image)
        return image, self.labels[idx]

Here is the full traceback
Traceback (most recent call last):
File “-/Documents/Code/AI/AI_Learning/Omniglot2/”, line 79, in
loss = crtieria(outputs, labels)
File “-AppData\Local\Programs\Python\Python36\lib\site-packages\torch\nn\modules\”, line 541, in call
result = self.forward(*input, **kwargs)
File “-\AppData\Local\Programs\Python\Python36\lib\site-packages\torch\nn\modules\”, line 916, in forward
ignore_index=self.ignore_index, reduction=self.reduction)
File “-\AppData\Local\Programs\Python\Python36\lib\site-packages\torch\nn\”, line 2009, in cross_entropy
return nll_loss(log_softmax(input, 1), target, weight, None, ignore_index, None, reduction)
File “-\AppData\Local\Programs\Python\Python36\lib\site-packages\torch\nn\”, line 1834, in nll_loss
if input.size(0) != target.size(0):
AttributeError: ‘tuple’ object has no attribute ‘size’

Could you please post the stack trace so that we can have a better look at your issue?
I cannot find anything obviously wrong in the current code snippet.

I edited the original post you should be able to see it. Do you need the Network code aswell?

Could you check the type of outputs and labels?
I guess labels is passed as a tuple instead of a tensor.
If so, you could return labels in your __getitem__ as:


I still have a question, when I make my labels to a tensor like that it gives me error about labels being a string(I know that they are) and I am suppose to make them integers right? Labels must be integers?
Do you have any suggestions for it?

Yes, nn.CrossEntropyLoss expects the target to be a LongTensor containing the class indices in the range [0, nb_classes-1].
If your current labels are stored as string, you might want to use a dict and map these strings to the corresponding indices.

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