replacement for new.instancemethod in Python3?
michele.simionato at gmail.com
Sun Apr 5 16:18:01 CEST 2009
On Apr 5, 3:58 pm, s... at pobox.com wrote:
> Michele> There is no need for new.instancemethod for new style classes:
> >>> class C: pass
> >>> c=C()
> >>> def f(self): pass
> >>> c.f = f.__get__(c, C)
> >>> c.f
> <bound method C.f of <__main__.C object at 0xb7b6fdec>>
> Like a chimpanzee I can mimic your use of __get__ (that is, use the pattern
> you've defined without understanding what it means), but based on the 3.1
> docs I haven't the slightest idea what it's really supposed to do:
> object.__get__(self, instance, owner)
> Called to get the attribute of the owner class (class attribute
> access) or of an instance of that class (instance attribute
> access). owner is always the owner class, while instance is the
> instance that the attribute was accessed through, or None when the
> attribute is accessed through the owner. This method should return
> the (computed) attribute value or raise an AttributeError exception.
> And what does object.__set__ do?
> object.__set__(self, instance, value)
> Called to set the attribute on an instance instance of the owner
> class to a new value, value.
> What attribute on the instance?
> I rather like functools.partial better than object.__get__. At least I can
> understand it.
Perhaps the docstring should contain a link to Raymond
Hettinger's descriptor essay: http://users.rcn.com/python/download/Descriptor.htm
More information about the Python-list