Ritchie python benchmark

bechmark.py

#!/usr/bin/env python
import time
from math import sqrt


class Timer(object):
    '''Provides a timer context'''

    def __enter__(self):
        self.start = time.time()
        return self

    def __exit__(self, *args, **kwds):
        self.end = time.time()
        self.elapsed = self.end - self.start
        print('Elapsed: {:>4.2} sec'.format(self.elapsed))


def isPrime(n):
    if (n < 2):
        return False
    elif (n == 2):
        return True
    elif (n % 2 == 0):
        return False

    upper_limit = int(sqrt(n))
    i = 3
    while (i <= upper_limit):
        if (n % i == 0):
            return False
        i += 2

    return True


def main():
    lim = 2000000
    no_primes = 0
    n = 0

    with Timer() as t:
        while (n <= lim):
            if (isPrime(n)):
                no_primes += 1
            n += 1

    print("Number of primes in the interval [0,%d]: %d" % (lim, no_primes))


if __name__ == '__main__':
    main()