Re: substitution of a method by a callable object

[Terry Reedy]

George Sakkis wrote:
On Oct 22, 12:13 pm, netimen <[EMAIL PROTECTED]> wrote:
Can I substitute a method of a class by a callable object (not a
function)? I can very easy insert my function in a class as a method,
but an object - can't.

I have the following:

class Foo(object):
    pass

class Obj(object):
    def __call__(self, obj_self):
        print 'Obj'

def func(self):
    print 'func'

f = Foo()
Foo.meth = func
f.meth() # all goes OK
Foo.meth = Obj()
f.meth() # I get TypeError: __call__() takes exactly 2 arguments (1
given)

You have to wrap it as an (unbound) instance method explicitly:

Nope.  As the error message says, the method was called with nothing 
provided to be bound to the extraneous parameter obj_self.  Either 
provide an arg, such as with f.meth(1), *or* delete obj_self and 'Obj' 
is printed, with both 2.5 and 3.0.

--
http://mail.python.org/mailman/listinfo/python-list