Steven Bethard <[EMAIL PROTECTED]> writes: > John J. Lee wrote: > > It seems nice to do this > > class Klass: > > def _makeLoudNoise(self, *blah): > > ... > > woof = _makeLoudNoise > > Out of curiosity, why do you want to do this?
I don't. It's just a habit I picked up from the standard library. > > 1. In derived classes, inheritance doesn't work right: > > > >>>>class A: > > ... def foo(s):print 'foo' > > ... bar = foo > > ... > >>>>class B(A): > > ... def foo(s):print 'moo' > > ... > >>>>b = B() > >>>>b.bar() > > foo > > Depends on what you mean by "work right". It does do what you asked > it to do. Well, gee, I guess so! By "right" simply meant "according to the intent of the people who tend to write such code" (and I do hope you're not going to get over-literal about *that* non-clinically-precise statement). It's obviously a tacit intent, though, hence the problem. > You asked class A to store the "foo" object under the name > "bar". When you create an instance of B, and ask for the "bar" > attribute, it isn't found in class B, so Python looks to the parent > class. The parent class, A, does have an object named "bar", so > Python returns that. And that object is the same object that you > asked be named bar, namely the "foo" function. Yes. My point was simply that the simplicity of writing method2 = method1 in a class body is an attractive nuisance. > If you want "bar" to be a function that *calls* the "foo" function, > declare it as such: > > py> class A(object): > ... def foo(self): > ... print 'foo' > ... def bar(self): > ... return self.foo() > ... > py> class B(A): > ... def foo(self): > ... print 'moo' > ... > py> B().bar() > moo It was my intent to push people to do that instead, yes. > > 2. At least in 2.3 (and 2.4, AFAIK), you can't pickle classes that do > > this. > > In Python 2.4: > > py> class A(object): > ... def foo(self): > ... print 'foo' > ... bar = foo > ... > py> import pickle > py> pickle.loads(pickle.dumps(A)).bar > <unbound method A.foo> > py> pickle.loads(pickle.dumps(A())).bar() > foo I meant class instances. John -- http://mail.python.org/mailman/listinfo/python-list
