1. The problem statement, all variables and given/known data Write a function, is_prime, which takes a single integral argument and returns True when the argument is a prime number and False otherwise. Add doctests to your function as you develop it. 2. The attempt at a solution Code (Text): def is_prime(n): x = 1 while x<=n: x+=1 if n%x==0: return False elif x==n: return True if __name__ == '__main__': import doctest doctest.testmod() I figure x goes from 2 to n, and if it finds a factor it returns false; otherwise, true. Why doesn't this work?