[Python-Dev] PEP 557: Data Classes

Mike Miller python-dev at mgmiller.net
Mon Sep 11 18:53:16 EDT 2017

On 2017-09-10 23:38, Michel Desmoulin wrote:
>> I'm going to put some words in explaining why I don't want to use base
>> classes (I don't think it buys you anything). Do you have a reason for
>> preferring base classes?
> Not preferring, but having it as an alternative. Mainly for 2 reasons:
> 1 - data classes allow one to type in classes very quickly, let's
> harvest the benefit from that.
> Typing a decorator in a shell is much less comfortable than using
> inheritance. Same thing about IDE: all current ones have snippet with
> auto-switch to the class parents on tab.
> All in all, if you are doing exploratory programming, and thus
> disposable code, which data classes are fantastic for, inheritance will
> keep you in the flow.
> 2 - it will help sell the data classes
> I train a lot of people to Python each year. I never have to explain
> classes to people with any kind of programming background. I _always_
> have to explain decorators.
> People are not used to it, and even kind fear it for quite some time.
> Inheritance however, is familiar, and will not only push people to use
> data classes more, but also will let them do less mistakes: they know
> the danger of parent ordering, but not the ones of decorators ordering.

I also feel inheritance is more intuitive (and easily entered), but missed the 
reason it wasn't chosen.  ;)


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