rain函数
train函数
def get_acc(output，label):
total = output.shape[0]
_，pred_label = output.max(1)
return (pred_label == label).sum().data.item()/total
def train(net，train_data，valid_data，num_epochs，optimizer，criterion):
if torch.cuda.is_available():
net = net.cuda()
time0 = time.time()
for epoch in range(num_epochs):
train_loss = 0
train_acc = 0
net = net.train()
time1 = time.time()
for im，label i
