So you can actually say, how do I know which methods are associated with the class? For that, we can call dir. And what it does, is it gives me back a listing of all the things, dir all the methods, that are associated with it.

我们开始建立类了，我们得到了这些方法,因此实际上你可以说，我怎么知道，哪些方法是关联与这些类的？,为了解决这个问题，我们可以调用，这个方法的作用。

麻省理工公开课 - 计算机科学及编程导论课程节选