# 加载预训练模型
 resNet50 = models.resnet50(pretrained=True)
 ResNet50 = ResNet(Bottleneck, [3, 4, 6, 3], num_classes=2)

 # 读取参数
 pretrained_dict = resNet50.state_dict()
 model_dict = ResNet50.state_dict()

 # 将pretained_dict里不属于model_dict的键剔除掉
 pretrained_dict = {k: v for k, v in pretrained_dict.items() if k in model_dict}

 # 更新现有的model_dict
 model_dict.update(pretrained_dict)

 # 加载真正需要的state_dict
 ResNet50.load_state_dict(model_dict)