exception in side if clause

[sbabu]

try:
#    def entr(n = int(input("Enter a no:  "))):
    Ask = int(input("Enter a no:  "))

    t = (2,3,4)
    if Ask in t:
        print("Valid No")
   
    else:
        print("Not valid")
        print("Enter Again:")
        raise ValueError
#        Ask = int(input("Enter a no:  "))
except Exception as e:
    print("The no is not in Tuple",e,Ask)

I am successful in checking whether the no entered is in the tuple. If not it raise exception. Up to that point OK.
Now I want to prompt the user to enter another no. How do I run line 6 and ask the user to enter again.

Thanks