But if it is not, it's going to print out a message here saying, you screwed up, somewhat politely, and it's going to go back around. So it'll just cycle until I get something of the right type.

但是输入不是浮点数的话,我这里就会显示一个消息说，你搞砸了，该稍微有点礼貌吧？,然后我们继续执行循环,一直到得到正确类型的输入。

麻省理工公开课 - 计算机科学及编程导论课程节选

And notice, by the way, when I typed it how print showed up in a different color?

注意，顺便说一下，当我输入的时候,怎样才能显示不同的颜色呢？

麻省理工公开课 - 计算机科学及编程导论课程节选

He'd have a screen saver showing pictures on the screen, paintings, and didn't say anything about them.

他的屏幕保护会在屏幕上显示一些照片，绘画，他什么都没有说。

耶鲁公开课 - 心理学导论课程节选

For example, if a car is going on a racetrack and you're seeing it from the top, if the speedometer says 60 miles per hour, you might say it's not accelerating.

例如,如果一辆车在跑道上行驶,你从上面俯视它,如果速率表显示的是60英里每小时,你也许会说它没有在加速

耶鲁公开课 - 基础物理课程节选

And again, if I just run this, just to show that it's going to do the right thing, it says enter base, I'm obnoxious, it says oops, wasn't a float, so we'll be nice about it and I enter a height, and it prints out what I expected. I just concatenated those strings together, by the way, at the end.

我再来运行下看是不是做对了,提示输入底，噢，它提示说不是浮点数，我很高兴，然后我输入一个,浮点数作为高度显示结果和我预期的相同,顺便说一句,我只是在最后把这些字符串连接起来了。

麻省理工公开课 - 计算机科学及编程导论课程节选

But notice what this does. The first thing it does is, it says, let's check and make sure x is greater than or equal to 0. If it isn't, notice what's going to happen. None of that block is going to get executed, and it's going to come down here and print out a useful piece of information, which says, hey, you gave me a negative number. I don't know how to do this.

做的是和以前一样的事情,但是注释它做了什么，第一件做的事情就是,程序说，要去检查并且确信x是大于等于0的，如果不是的话，请注意会发生什么,下面的代码都不会被执行,程序会到这里来然后显示一些有用的信息,信息会说，嘿，你给了我一个负数,我不知道该怎么弄这个了。

麻省理工公开课 - 计算机科学及编程导论课程节选