神经网络训练模型的两种写法

Example1：

for input, target in dataset:optimizer.zero_grad()output = model(input)loss = loss_fn(output, target)loss.backward()optimizer.step()

Example2：

for input, target in dataset:def closure():optimizer.zero_grad()output = model(input)loss = loss_fn(output, target)loss.backward()return lossoptimizer.step(closure)

参考：pytorch API