1. import torch
    2. import torch.nn as nn
    3. import torch.optim as optim
    4. from torch.optim import lr_scheduler
    6. t = torch.tensor([0.0], requires_grad=True)
    7. optim = torch.optim.SGD([t], lr=0.01)
    8. lr_scheduler = lr_scheduler.MultiStepLR(optim, milestones=[10, 20])
    10. lrs = []
    11. for e in range(20):    
    12.     optim.step()
    13.     lr_scheduler.step()
    14.     lrs.append((e, optim.param_groups[0]['lr']))
    16. lrs = np.array(lrs)
    18. plt.figure(figsize=(10, 5), dpi=100)
    19. plt.grid()
    20. plt.xticks(range(0, 20, 1))
    21. plt.plot(lrs[:, 0], lrs[:, 1])