Python 2.6: Determining if a method is inherited

[Fuzzyman]

Hello all,

I may well be being dumb (it has happened before), but I'm struggling
to fix some code breakage with Python 2.6.

I have some code that looks for the '__lt__' method on a class:

if hasattr(clr, '__lt__'):

However - in Python 2.6 object has grown a default implementation of
'__lt__', so this test always returns True.

>>class X(object): pass

....

>>X.__lt__

<method-wrapper '__lt__' of type object at 0xa15cf0>

>>X.__lt__ == object.__lt__

False

So how do I tell if the X.__lt__ is inherited from object? I can look
in the '__dict__' of the class - but that doesn't tell me if X
inherits '__lt__' from a base class other than object. (Looking inside
the method wrapper repr with a regex is not an acceptable answer...)

Some things I have tried:

>>X.__lt__.__se lf__

<class '__main__.X'>

>>dir(X.__lt_ _)

['__call__', '__class__', '__cmp__', '__delattr__', '__doc__',
'__format__', '__getattribute __', '__hash__', '__init__', '__name__',
'__new__', '__objclass__', '__reduce__', '__reduce_ex__' , '__repr__',
'__self__', '__setattr__', '__sizeof__', '__str__',
'__subclasshook __']

>>X.__lt__.__fu nc__

Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'method-wrapper' object has no attribute '__func__'

Michael Foord
--
http://www.ironpythoninaction.com/

[Terry Reedy]

Fuzzyman wrote:

On Oct 6, 7:02 pm, Terry Reedy <tjre...@udel.e duwrote:

>fuzzyman wrote:

>>Doesn't sound like a particularly *good* solution to me. :-)

From what you posted, 'type object at' should work.

It's still a hack...

I am sorry if I offended you by pointing out to you a quick and dirty
solution that would solve your problem immediately.

[Fuzzyman]

On Oct 7, 2:29*am, Terry Reedy <tjre...@udel.e duwrote:

Fuzzyman wrote:

On Oct 6, 7:02 pm, Terry Reedy <tjre...@udel.e duwrote:

fuzzyman wrote:
Doesn't sound like a particularly *good* solution to me. :-)
*From what you posted, 'type object at' should work.

It's still a hack...

I am sorry if I offended you by pointing out to you a quick and dirty
solution that would solve your problem immediately.

Your smiley parsing is obviously broken.

Michael