py 蒙特卡洛 pi

import random
import time
random.seed()
nums=100000
i=range(1,nums)
s=0
for x in i:
    for y in i:   
        a1=random.random()
        a2=random.random()
        if (a1*a1+a2*a2)<1:
            s=s+1

print 1.0*s/(nums*nums)*4

print time.strftime('End:%Y-%m-%d  %H:%M:%S',time.localtime(time.time()))