用sys和time模块实现进度条

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

if __name__ == ‘__main__‘:
    for i in range(0, 101):
        time.sleep(0.1)
        view_bar(i, 100)