Understanding how methods in classes work.

Hi Steven Parker your answers are always great, so thanks for that! Just wondering in this specific case you said __radd__ won't bounce back to __add__, but it kind of does doesn't it? We've redefined within the class how the + operator works by creating the __add__ method no? That's why we don't need the following code within __radd__ to make it work right?

if '.' in self.value:
            return float(self) + other
        else:
            return int(self) + other

Because it uses the + operator which already includes that code? Or am I completely off base here

I was creating a distinction between "bounce back" (program flow) and "pass back" (returning a value).

And yes, you have defined what addition does with these objects, and you only need to code the operation once.

Only the method(s) that pertain to the operation being performed will be used, and only the reflected ("r" version) will be used if the primary one is not present or fails. For example, if two items are being added ("+") the "__add__" and/or "__radd__" will be used, but not those for other operations (like "__sub__" for instance).

Depending on what your class represents, the concept of of operations like "adding" them might not be handled as you would want by default, so you can create custom versions.

For example, if the class was "animal", Python might not know offhand how to add a "moose" and a "squirrel". But you can define how.

I got alerted by your tag.

Most everything I know about Python I learned right here at Treehouse!

My favorite go-to reference is the official documentation at Python.org.