How to rearrange the sample order of a torch dataloader?

I have a “torch.utils.data.DataLoader”. I want to rearrange the order of the samples. Is it possible?

Answer

Yes, you can use torch.utils.data.Subset and specify the indices.

import numpy as np
import torch
from torch.utils.data import DataLoader, Subset, TensorDataset


data = np.arange(5) ** 2
dataset = TensorDataset(torch.tensor(data))

# Subset with entire Dataset in rearranged order
dataset_ordered = Subset(dataset, indices=[2, 1, 3, 4, 0])

for x in DataLoader(dataset_ordered):
    print(x)

# [tensor([4])]
# [tensor([1])]
# [tensor([9])]
# [tensor([16])]
# [tensor([0])]