Adding and modifying methods at run-time

[Thomas Weholt]

That worked great !!! Thanks alot.

Thomas


"Diez B. Roggisch" <deetsNOSPAM at web.de> wrote in message
news:c707s0$q4m$03$1 at news.t-online.com...
> Thomas Weholt wrote:
> > a = A()
> > a.addNewMethod(1, a.obj1)
> > # use new dynamically method
> > a.method4obj1(1,2) # now the third param with a default is set to point
to
> > obj1 instead of None
> >
> > I'm crashing at the copy-method in addNewMethod. It crashes with the
> > exception "TypeError: function() takes at least 2 arguments (0 given)".
> > This is deep inside the copy-module.
> >
> > Any hints or clues?
>
> I have to admit that I'm not fully undestanding what your code above is
> supposed to do - but form what  I understand you try to introduce a new
> method on an object where a certain named parameter is bound to a special
> value.
>
> Now this problem can be split into two parts:
>
> 1 - create a method that has a paramter bound to a certain value
> 2 - add that method to an object instance
>
> The first thing is known as currying, and there is a cookbook recipe that
> does that very well:
>
> http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52549
>
> You will end up with a new method that can be invoked. Now to make this an
> instance method, remove the space between the last two words before the
> comma in this sentence and look up the result in the python docs :)
>
> Seriously, all you need is the function instancemethod from the module
new.
> Use it to create a new method on your instance.
>
> The following program illustrates the concepts, the curry-fun is  taken
from
> the recipes comments:
>
> import new
>
> def curry(*args, **create_time_kwds):
>     func = args[0]
>     create_time_args = args[1:]
>     def curried_function(*call_time_args, **call_time_kwds):
>         args = create_time_args + call_time_args
>         kwds = create_time_kwds.copy()
>         kwds.update(call_time_kwds)
>         return func(*args, **kwds)
>     return curried_function
>
>
> class foo:
>     def method(_, arg1, named_arg=None):
>         print (arg1, named_arg)
>
> f = foo()
>
> f.method(1)
>
> new_m = curry(foo.method, named_arg="something")
>
> new_m(f,2)
>
> f.new_m = new.instancemethod(new_m, f, foo)
>
> f.new_m(3)
>
>
>
>
> --
> Regards,
>
> Diez B. Roggisch