How to modify internal ImageFolder object after creation?

1

I am trying to port some dataloader codes from codebase 1 to codebase 2.
For codebase 2, the dataloader was based on ImageFolder, while the dataloader in codebase 1 was something where. What I did was to replace the getitem of codebase2 with the one from codebase1, and it worked well.

However, the other part of codebase 2 (which I cannot modify due to some internal policy) will read the total number of samples by doing len(train_loader), where “train_loader” is the ImageFolder object.

So I am thinking if I can hack it a little bit to modify the attributes of this ImageFolder object “train_loader”, so that len(train_loader) will return the desired value. I need to do that after this object was created, and I tried “self.samples = []” to see whether len(train_loader) will become 0, but nothing happened.

Could someone provide some guidance on this? Thanks.

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Removing all internal self.samples should work, as the DatasetFolder class uses this attribute to get the length as seen here.
Alternatively, you could also try to monkey-patch the __len__(self) method and assign the desired value to it, assuming you want to reduce the number of samples and remove the last samples.
With that being said, I don’t know what your use case is and would generally recommend to create either a new Dataset with the desired attributes or create a custom one.

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