Why "None" is also getting printed everytime ?

Question

# This code is to check whether a number is prime or not ?
def is_num_prime(x) :
for i in range(2,x) :
d = x%i
if d == 0 :
print('num is not prime')
break
else :
print('num is prime')
print(is_num_prime(13))

Answer 1

If your function does not have a return statement, it returns None by default. This is the same case. What you are actually doing is passing the return value of is_num_prime to print, which is None. So None is printed. Change
print(is_num_prime(13))
to
is_num_prime(13)

Answer 2

I got it.
Thanks XXX