I am trying to implement  – “The learning rate is decayed exponentially from 0.01 to 0.0001 for 30 epochs.”
I found lr_scheduler = optim.lr_scheduler.ExponentialLR(optimizer, gamma)
optimizer = optim.Adam()
lr_scheduler = optim.lr_scheduler.ExponentialLR(optimizer, gamma)

for epoch in range(nb_epoch):
        for data in train_loader:
                ....
                ....
                optimizer.step()
lr_scheduler.step()

So how do I use the epoch and learning rate 0.01 to 0.0001 in this case?