>>> def isPrime(n):
...     q = math.sqrt(n)
...     for i in xrange(2, q+1):
...         if n % i == 0: return False
...     return True

>>> def prob10():
...     import time
...     start = time.clock()
...     sm = 0
...     for i in range(2, 2000000):
...         if isPrime(i): sm+= i
...     print time.clock() - start
...     return sm