python print 一个进度条

import time
scale=100
print("执行开始".center(scale+28,'-'))
start = time.perf_counter()
for i in range(scale+1):
    a = '*' * i
    b = '.' * (scale - i)
    c = (i/scale)*100
    t = time.perf_counter() - start
    print("\r任务进度:{:>3.0f}% [{}->{}]消耗时间:{:.2f}s".format(c,a,b,t),end="")
    time.sleep(0.03)
print("\n"+"执行结束".center(scale+28,'-'))

执行结果：

--------------------------------------------------------------执行开始--------------------------------------------------------------
任务进度:100% [****************************************************************************************************->]消耗时间:3.26s
--------------------------------------------------------------执行结束--------------------------------------------------------------