This is like Interface
in Go (or Java, i don’t speak Java but the article say so).
Oh nice, I did not know about the Protocol class. It seems handy when I have to deal with untyped 3rd party modules.
OK, but why would I use this over ABCs? (Abstract Base Class). Or is it just different?
From what i understand,
Protocol
is for custom interfaces that you define (this object must havedo_x()
method), while ABCs are generic (this object is iterable).@nikaro iterable means: has __iter__() method. So there’s no real difference, as far as I can see.
The difference is that with
Protocol
you can define which method presence you want to ensure. Like i said: custom vs. generic.
Protocols are static duck typing. An object is a valid instance of protocol if it implements all the methods defined in the protocol, even if it doesn’t declare it as implementing it. That last bit is important and the most distinguishing factor compared to an ABC.