[Python-ideas] PEP proposal: unifying function/method classes

[Serhiy Storchaka]

28.03.18 20:22, Erik Bray пише:
> On Fri, Mar 23, 2018 at 11:25 AM, Antoine Pitrou <solipsis at pitrou.net> wrote:
>> One breaking change would be to add __get__ to C functions.  This means
>> e.g. the following:
>>
>> class MyClass:
>>      my_open = open
>>
>> would make my_open a MyClass method, therefore you would need to spell
>> it:
>>
>> class MyClass:
>>      my_open = staticmethod(open)
>>
>> ... if you wanted MyClass().my_open('some file') to continue to work.
>>
>> Of course that might be considered a minor annoyance.
> 
> I don't really see your point in this example.  For one: why would
> anyone do this?  Is this based on a real example?  2) That's how any
> function works.  If you put some arbitrary function in a class body,
> and it's not able to accept an instance of that class as its first
> argument, then it will always be broken unless you make it a
> staticmethod.  I don't see how there should be any difference there if
> the function were implemented in Python or in C.

Yes, there are real examples. Good or bad, it is well known behavior of 
builtin functions, and real code depends on it. For sure changing it 
will break a lot of user code (and also the Python stdlib and  tests).

Just try to implements the support of the descriptor protocol in builtin 
functions and you will see how much code this will break.