size()

- [Narrator] Since we're representing our stack with a list,…in order to figure out how many items are in the stack,…all we need to do is use the list's built-in length method…to find the length of the underlying list.…So, we'll come into our size method here…and really all I need to do is just return the result…of calling that length method.…So, we'll do, basically, find the length of self.items.…I'll save this, and then go back to my terminal…and run the file, interactively, of course.…

And here, I am going to create my own stack object…and before I add anything to it,…I want to check my size method,…make sure I've coded it properly.…So, we'll do my_stack.size, and I expect to get zero.…Yep, that's what I get.…So now, let's push something onto the stack.…We'll do apple again.…Okay, and if I call the size method again,…I expect that it would return one.…

And that's what I get.…So, let's go back to the code here…and we'll add our doc string and runtime note,…as we have been.…So, what does this method do?…This method returns the length of the list…