LambdaDataset?

I’m wondering if this is of interest to the torchvision community: a dataset defined with two functions. It would look like this:

wrapped_dset = # some dataset

def data(i):
    return wrapped_dset[i][0]

def target(i):
    return data(i)[:, ::2, ::2]  # downsample on the fly

dset = LambdaDataset(data_func=data, target_func=target, length=len(wrapped_dset))

It could be super-handy to combine datasets, switch out the target like above, etc., without having to write a separate class.

[kohr-h]

Yeah, I tried to bring forth the best arguments, but they’re not really that strong. And I understand the reasons against.

[fmassa]

Thanks for the understanding @kohr-h But there might be other places that such a functionality might be desired, for example as a third-party package?