去掉最后两层
import torchvision.models as models
from torch import nn
net = models.resnet18(pretrained=True)
net2 = nn.Sequential(*list(net.children())[:-2])
修改最后一层
import torchvision.models as models
from torch import nn
net = models.resnet18(pretrained=True)
print(net) #查看最后一层的情况
net.fc = nn.Linear(512, 2) #将最后一层改为二分类