So then in order to figure out the complete number of valence electrons in our molecule, we just add 5 plus 4 plus 1.

那么接下来为了得到,这个分子中价电子的总个数，我们只需要将五加上四，再加上一。

麻省理工公开课 - 化学原理课程节选

That is we'd like to be able to get pieces of them out. We'd like to be able add them together or concatenate them together.

我们也可以对字符串进行切片,实际上这些都可以,因此字符串也支持选择，切片。

麻省理工公开课 - 计算机科学及编程导论课程节选

OK, I can certainly print out strings, but I can actually add strings together, and just as you saw, I can multiply strings, you can kind of guess what this is going to do.

当然我可以显示字符串，但是其实我还可以令字符串相加，如你所见到的，我可以令字符串相乘，你们可以想想答案是什么。

麻省理工公开课 - 计算机科学及编程导论课程节选

It took me seven comparisons, because I can take advantage of the fact I know I only ever have to look at the first element of each sub-list. Those are the only things I need to compare, and when I run out of one list, I just add the rest of the list in.

进行了7次对比，因为我可以利用我知道的优势：,每次只需要比较每个子列表的第一个元素,那才是我需要进行对比的内容,当一个列表的元素处理完了,只需要将另一个列表剩下的元素直接添加进去。

麻省理工公开课 - 计算机科学及编程导论课程节选

All right? And if you want to do other things, whoops, sorry-- and add them together, we will get out, again, a concatenation of that string. And these will, we'll let you work through the variations, but these are the simple expressions we can use.

对不对？如果你想要进行一些别的操作，哦，对不起-是加到一块，然后结果值也是，两个字符串的链接，这些会，我们会让大家慢慢学习变量，但是这些是我们能用的最简单的表达式。

麻省理工公开课 - 计算机科学及编程导论课程节选