# Returns a list of primes less than 'n'. import is_prime def leq_primes(n): import time start=time.clock() li=[2] for i in range(3,n,2): if is_prime.is_prime(i)==True: li.append(i) sum=0 for e in li: sum=sum+e run_time = time.clock() - start return sum,run_time if __name__ == "__main__": n = raw_input("Input: ") n = int(n) print leq_primes(n)

and here is the code for is_prime.py file,

# Returns true if a number is prime,returns false other wise. def is_prime(n): d=True r=int(n**.5)+1 # sets r as root(n) +1 for i in range(2,r,1): # looking just at ood numbers, as all primes are odd, except 2 if n%i == 0: d=False return d if __name__ == "__main__": n = raw_input("Input: ") n = int(n) print is_prime(n)