module 'torch.nn' has no attribute 'ReLu'

The correct spelling for the activation function is `ReLU` (capitalized). Therefore, the correct attribute name in PyTorch is `ReLU` with a capital "L". You can use it like this:

import torch.nn as nn

relu = nn.ReLU()

This will create an instance of the `ReLU` activation function that you can use in your neural network.