Python's super() considered super!

[Duncan Booth]

sturlamolden <sturlamolden at yahoo.no> wrote:

> On 26 Mai, 18:31, Raymond Hettinger <pyt... at rcn.com> wrote:
>> I just posted a tutorial and how-to guide for making effective use of
>> super().
>>
>> One of the reviewers, David Beazley, said, "Wow,  that's really
>> great!    I see this becoming the definitive post on the subject"
>>
>> The direct link is:
>>
>>  http://rhettinger.wordpress.com/2011/05/26/super-considered-super/
> 
> I really don't like the Python 2 syntax of super, as it violates
> the DRY principle: Why do I need to write super(type(self),self)
> when super() will do? Assuming that 'self' will always be named
> 'self' in my code, I tend to patch __builtins__.super like this:
> 
> import sys
> def super():
>     self = sys._getframe().f_back.f_locals['self']
>     return __builtins__.super(type(self),self)
> 
> This way the nice Python 3.x syntax can be used in Python 2.x.
> 
> 
Oh dear, you haven't thought this one through.

After your code above, try this:

>>> class A(object):
	def foo(self):
		print "A.foo"

		
>>> class B(A):
	def foo(self):
		print "B.foo"
		super().foo()

>>> B().foo()
B.foo
A.foo

So far so good.
Now try this:

>>> class C(B): pass

>>> C().foo()
... infinite recursion follows ...

Oops. There's a reason why Python 2 requires you to be explicit about 
the class; you simply cannot work it out automatically at run time. 
Python 3 fixes this by working it out at compile time, but for Python 2 
there is no way around it.


-- 
Duncan Booth http://kupuguy.blogspot.com