答案:import timescale = 50print("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,'-'))