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 to the subject? When and how do I use this exactly?

Answer 1

You can view a full example here:

• http://www.diveintopython.net/power_of_introspection/index.html

Introspection can be used for different purpose, the one presented in 'Dive Into Python' is simply a way to add functionality (plug-in) dynamically in your application.

By dynamically I mean without doing modification in the core application to add a new feature.

Taking the 'Dive Into Python' example - a simple app to extract attribute from file of different file - you can add the handling of a new file format without doing modification to the original application.

I recommend that you finish the book. As you read, everything will become increasingly clear.