What is getattr() exactly and how do I use it?

Question

I was reading about the getattr() function. The problem is that I still can't grasp the idea of its usage. The only thing I understand about getattr() is that getattr(li, "pop") is the same as calling li.pop.

I didn't understand when the book mentioned how you use it to get a reference to a function without knowing its name until run-time. Maybe this is me being a noob in programming, in general. Could anyone shed some light on the subject? When and how do I use this exactly?

Answer 1

The getattr(object, 'x') is completely equivalent to object.x.

There are only two cases where getattr can be useful.

• you can't write object.x, because you don't know in advance which attributes you want (it comes from a string). very useful for meta-programming.

• you want to provide a default value. object.y will raise an AttributeError if there's no y. But getattr(object, 'y', 5) will return 5.

To know more about this you can have a look at the following video tutorial:-