[Python-Dev] Language reference updated for metaclasses

[Nick Coghlan]

It's actually the pre-decoration class, since the cell is initialised
before the class is passed to the first decorator. I agree it's a little
weird, but I did try to describe it accurately in the new docs.

--
Sent from my phone, thus the relative brevity :)
On Jun 5, 2012 7:52 AM, "PJ Eby" <pje at telecommunity.com> wrote:

> On Sun, May 20, 2012 at 4:38 AM, Nick Coghlan <ncoghlan at gmail.com> wrote:
>
>> When writing the docs for types.new_class(), I discovered that the
>> description of the class creation process in the language reference
>> was not only hard to follow, it was actually *incorrect* when it came
>> to describing the algorithm for determining the correct metaclass.
>>
>> I rewrote the offending section of the language reference to both
>> describe the correct algorithm, and hopefully also to be easier to
>> read. Once people have had a chance to review the changes in the 3.3
>> docs, I'll backport the update to 3.2.
>>
>> Previous docs:
>> http://docs.python.org/py3k/reference/datamodel.html#customizing-class-creation
>> Updated docs:
>> http://docs.python.org/dev/reference/datamodel.html#customizing-class-creation
>>
>
> This is only sort-of-related, but while reviewing the above, the bit about
> __class__ caught my eye and brought this question to mind: how do class
> decorators interact with __class__?  Specifically, what happens (or more to
> the point, is *supposed* to happen and documented as such) if a class
> decorator returns a different class object?
>
> PEP 3135 doesn't address this, AFAICT.  It refers only to "the class", but
> doesn't say whether this is the class-as-returned-by-decorator or original
> defined class.  (ISTM that it should be the decorated class, since
> otherwise this would be different behavior compared to code that explicitly
> named the class.)
>
> (Oh, and the rewrite looked good!)
>
>
>
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