hi,
scheduler1 = ConstantLR(optim, factor=0.1, total_iters=400)
scheduler2 = MultiStepLR(optim, milestones=[32000,48000], gamma=0.1)

# in training inner loop
for j, x,t in enumerate(dl):
        optim.zero_grad()
        out=model(x)
        loss = criteria(out,t.long())
        loss.backward()
        optim.step()
        totalLoss += loss.item()
        if i*len(dl) + j <400:
            scheduler1.step()
            scheduler2.step()
        else:
            scheduler2.step()

I’m not sure  that if statement is necessary anymore.
also, You can use LAMBDALR to do anything you want.