算Π

本进度条是根据随机点的个数而改变的，落下一个点则更新一次，所以点越多，运行时间越长，该进度条可实现实时更新

方法亦是蒙特卡罗法

from random import random
from math import sqrt
import time
DARTS=100000**2
hits=0.0
start_time = time.perf_counter()
for i in range(1,DARTS+1):
    x,y=random(),random()
    dist=sqrt(x**2+y**2)
    a = '*' * i
    b = '.' * (DARTS - i)
    c = (i / DARTS) * 100
    end_time = time.perf_counter()
    elapsed_time = end_time - start_time
    print("\r{:^3.0f}%[{}->{}]{:.2f}s".format(c, a, b, elapsed_time), end='')
    time.sleep(0.05)
    if dist<=1.0:
        hits=hits+1
pi=4*(hits/DARTS)
print("Pi值是{}.".format(pi))