A progress bar is not supposed to print one hundred lines just to update its status; generally we like to see a little animation.

一个进度条不应该是打印100行,只是更新它的状态，一般地，我们,想看到一点生机。

哈佛公开课 - 计算机科学课程节选

It's going to be my sort of simple implementation of a progress bar.

它将是一种我的,简单的执行进度条。

哈佛公开课 - 计算机科学课程节选