[Python-Dev] What is the design purpose of metaclasses vs code generating decorators? (was Re: PEP 557: Data Classes)

[Ivan Levkivskyi]

On 14 October 2017 at 17:49, Ethan Furman <ethan at stoneleaf.us> wrote:

> The problem with PEP 560 is that it doesn't allow the class definition
> protections that a metaclass does.
>

Since the discussion turned to PEP 560, I can say that I don't want this to
be a general mechanism, the PEP rationale section gives
several specific examples why we don't want metaclasses to implement
generic class machinery/internals.

Could you please elaborate more what is wrong with PEP 560 and what do you
mean by "class definition protections"

--
Ivan
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