def is_prime(x):

prime = "yes"

if x == 0 or x == 1 or x < 0:

return False

for i in range(2,x-1):

if x % i == 0:

prime = "no"

if prime == "yes":

return True

else:

return False

**** I would just like to point out that 0 is a prime number and 1 is not a prime number.