Thank you very much for this help. I could actually solve the problem of attribute error.
I read the link you gave.
Then I understood the meaning of the error that was being given.
AttributeError: Can’t get attribute ‘CifarVggnet’ on <module ‘main’ from ‘Checking.py’>

It turns out that may be the Checking.py file may not be successful in importing the model definition from vgg.py
To make it work I did the following:
from model.vgg import *

instead of:
from model import *

and
from model import vgg

The problem got resolved due to this line.
Thankyou very much @ptrblck for bearing my non-stop comments and replies.