python 循环中显示进度条

import sys


# 循环时显示进度条
# total 代表循环总数 ，num为当前循环数

def view_bar(num, total):
    rate = float(num) / float(total)
    rate_num = int(rate * 100)
    r = '\r[%s%s]%d%%,%d' % ("="*rate_num, " "*(100-rate_num), rate_num, num )
    sys.stdout.write(r)
    sys.stdout.flush()

import time
for i in range(100):
    time.sleep(1)
    view_bar(i , 100)

'''
[=========                           ]9%,9
'''