I encountered this error after modification. What is going on?

def get_lab_src(batch_size):

    src_dataset_root = scipy.io.loadmat('E:\\ADDA\\adda-lab\\datasets\\lab\\test_target_domain_maria.mat')
    s_data = src_dataset_root['testdata'] 
    s_data = torch.from_numpy(s_data).float()
    

    s_label = src_dataset_root['testlabel'] 
    s_label = torch.from_numpy(s_label).long() 

    s_dataset = torch.utils.data.TensorDataset(s_data, s_label)
    s_loader = torch.utils.data.DataLoader(dataset=s_dataset, batch_size=batch_size, shuffle=True, drop_last=True, num_workers=1)

    return s_loader