extending an existing class without inhertance

[Troy Melhase]

Hi Martin:

Check out the 'new' module.  Here's a quick example:

Python 2.2.2 (#1, Dec 23 2002, 15:44:51)
[GCC 2.95.3 20010315 (release)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
 >>> class MyClass:
...     def op(self):
...             print self
...
 >>> def other_op(self, arg):
...     print self, arg
...
 >>> mine = MyClass()
 >>> mine.op()
<__main__.MyClass instance at 0x8114d04>
 >>> import new
 >>> mine.new_op = new.instancemethod(other_op, mine, MyClass)
 >>> mine.new_op
<bound method MyClass.other_op of <__main__.MyClass instance at 0x8114d04>>
 >>> mine.new_op('a')
<__main__.MyClass instance at 0x8114d04> a
 >>>

Good luck.

- troy

Martin Schmettow wrote:
> Hi anybody.
> 
> I am working on a script which uses several XML techniques (building 
> DOM,XSLT).
> For building the DOM I started using the xml.dom module. This module 
> implements the setAttribute() method on element nodes.
> For some reasons I have to switch to the Ft.Xml.Domlette implementation, 
> where the setAttribute() is missing.
> Extending the class by inheritance is obvious but seems not practical in 
> this case, because a lot is done by Factories, which you cant just tell 
> to produce MyElement instead of Element.
> The easiest solution would be to enhance the existing class by just 
> adding the method. I did this several times in Perl (in a former life, 
> of course).
> Can anybody tell me the Python way to do it. Other solutions are welcome 
>  as well.
> 
> CU
> Martin.
>