进度条

import time
scale=50
print("执行开始".center(scale//2,"-"))
start=time.perf_counter()
for i in range(scale+1):
a='*' * i
b='.' * (scale-i)
c=(i/scale)*100
dur=time.perf_counter()-start
print("\r{:.^3.0f}%[{}->{}]{:.2f}s".format(c,a,b,dur),end='')
time.sleep(0.1)
print("\n"+"执行结束".center(scale//2,'-'))