[Python-Dev] Problems with the new super()

[Georg Brandl]

Armin Ronacher schrieb:

>> The super() thing is a case of practicality beats purity. Note that
>> you pay a small but measurable cost for the implicit __class__ (it's
>> implemented as a "cell variable", the same mechanism used for nested
>> scopes) so we wouldn't want to introduce it unless it is used.
> I do agree that super() is a lot easier to work with than regular way to
> call it.  But the fact that it breaks if i do `_super = super` or that
> it's impossible to emulate it from within Python.

That it isn't emulatable from Python doesn't bother me -- several functions
have that property.

But the other two magical things about super() really bother me too. I
haven't looked at the new super in detail so far (and I don't know how
many others have), and two things are really strikingly unpythonic in
my view:

* super() only works when named "super" [1]. It shouldn't be a function if
   it has that property; no other Python function has that.

* "__class__" is magical in classes. If you define a local called "__class__"
   super won't work anymore in that function.

   Also, you can access "__class__" from any method, without the "self."
   qualifier -- another magical name.

   There may be more implications and surprising behavior surrounding this.

I know that the implementation is a compromise, but I'd rather see a super()
whose full semantics can be explained to programmers without using to
"cell variable", "f_localsplus" and "symtable".

cheers,
Georg

[1] Actually, it only works if a name "super" is accessed somewhere in the
     function, but this is what someone trying to alias "super" will perceive.

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