reload_dataloaders_every_n_epochs: how to modify dataloader inside Datamodule

[s6mahahn]

I hope this is not answered already.

I have the following situation:
I need to change the dataset used every 2 epochs. In my datamodule i want to return different parts of the train dataset depending on the current epoch. I have seen the suggestion to use self.current_epoch (#7372). But that seems to not exists as i get the error: 'DataModule' object has no attribute 'current_epoch'.

Am I doing something wrong? Or what would be the correct to do it?

class MyDM(pl.lightningDataModule):
    def __init__(self,):
        <init some stuff>

  some other methods that do stuff

   def train_dataloader(self):
        return DataLoader(
            self.train[self.current_epoch],
            batch_size=self.batch_size,
            num_workers=self.num_workers,
        )

model = MyModel()
data = MyDM()
trainer pl.Trainer(reload_dataloaders_every_n_epochs=5)
trainer.fit(model, data)