为什么我收到消息“UserWarning：给定的 NumPy 数组不可写，并且 PyTorch 不支持不可写张量。”？

Question

我正在构建自己的数据集：

class MyDataset(Dataset):
    def __init__(self, folders):                
        self.folders         = folders                
        
        
    def __len__(self):            
        return len(self.folders)
        
    
    def __getitem__(self, item):
                         
        pos_file_list =  glob(self.folders[item] + "/*")            
        positive_img  = pos_file_list[1]
                
        positive_img   = mpimg.imread(positive_img)                
        positive_img   = np.transpose(positive_img,     (2,0,1))                    

        # positive_img have the type: <class 'numpy.ndarray'>, shape: (3, 128, 128)        
        return positive_img

我正在使用它：

batch_size =  128      
train_ds   = MyDataset(train_folder_list)


oTrainDL   = DataLoader(train_ds, batch_size=batch_size, shuffle=True, num_workers=2)        


for i, imgs in enumerate(oTrainDL):                       
    break

我收到以下警告：

UserWarning: The given NumPy array is not writeable, and PyTorch does not support non-writeable tensors. This means you can write to the underlying (supposedly non-writeable) NumPy array using the tensor. You may want to copy the array to protect its data or make it writeable before converting it to a tensor. This type of warning will be suppressed for the rest of this program. (Triggered internally at  ../torch/csrc/utils/tensor_numpy.cpp:189.)
  return default_collate([torch.as_tensor(b) for b in batch])

为什么我会收到警告消息？我该如何解决它？

Answer 1

从

return positive_img

更改为：

return torch.tensor(positive_img)