Python : Can we use magic/dunder methods as instance attributes directly instead of putting them in type definition?

Readul Hasan Chayan [Heemayl] — Fri, 22 Mar 2019 13:11:05 GMT

No, we can't.

The magic/dunder methods are looked up implicitly on the type definition while special functions, keywords, or operators are to be resolved by the runtime. They don't follow the regular attribute lookup procedure i.e. doesn't follow the __getattribute__ chain. This makes them fast to access as the runtime only needs to search on the type, not on instance dict.

So, what about classes themselves? What dunder methods should be used when any special function is called on them?

As any class is an instance of a metaclass, the dunder methods defined on the metaclass would be used.

Let's see a few examples to get a clear overview of all these. We'll be using the repr function, for which the interpreter will call __repr__ dunder method implicitly, in order to get the representation of an object.

Readul Hasan Chayan [Heemayl] (Posts about oop)

Python : Can we use magic/dunder methods as instance attributes directly instead of putting them in type definition?