I tried it now, but it is giving me the same error.
  1 import torch                                                                
  2 import torch.nn as nn
  3 import torch.optim as optim
  4 import torch.nn.functional as F
  5 
  6 import torchvision
  7 import torchvision.transforms as transforms
  8 from model import vgg
  9 import numpy as np
 10 from torch.utils.data.dataset import Dataset
 11 
 12 net=CifarVggnet()
 13 ckpt_path='/home/students/soumyajit_po/hsd_cnn_code/SOUMYA/checkpoint/vggCif    ar10TEST.pth.tar'
 14 #model=vgg.model
 15 #print(model)
 16 checkpoint=torch.load(ckpt_path,map_location=lambda storage,loc:storage)

And the error is
Traceback (most recent call last):
  File "Checking.py", line 12, in <module>
    net=CifarVggnet()
NameError: name 'CifarVggnet' is not defined

This is my vgg.py inside model folder
 import torch.nn as nn                                                       
 import torch.optim as optim
 import torch.nn.functional as F
 import torchvision.models as models
 vggnet=models.vgg16_bn(pretrained=True)
 
 classifier=list(vggnet.classifier.children())[:-6] 
 features=list(vggnet.features.children())
 features.extend(nn.Sequential(nn.AvgPool2d(1, stride=1, padding=0, ceil_mode    =False, count_include_pad=True)))
 avgpool=list(vggnet.avgpool.children())[:-1]
 vggnet.features=nn.Sequential(*list(features))
 vggnet.classifier=nn.Sequential(*list(classifier))
 vggnet.classifier[0]=nn.Linear(512,10)
 vggnet.avgpool=nn.Sequential(*list(avgpool))
 
 class CifarVggnet(nn.Module):
     def __init__(self,vggnet):
         super(CifarVggnet,self).__init__()
         self.vggnet=vggnet
     
     def forward(self,x):
         return self.vggnet(x)
 
 model=CifarVggnet(vggnet)