[Tutor] Calling super classs __init__?
luciano at ramalho.org
Wed Mar 19 04:45:33 CET 2008
Nowadays the best practice for invoking a method from all superclasses
(yes, multiple inheritance) is this:
def __init__(self, t, *args, **kw):
super(SubClass, self).__init__(*args, **kw)
# do something with t
That way you let Python decide which superclasses your SubClass has,
instead of hard-coding it in several places.
On Tue, Mar 18, 2008 at 9:37 PM, John Fouhy <john at fouhy.net> wrote:
> On 19/03/2008, Allen Fowler <allen.fowler at yahoo.com> wrote:
> > I have a super class that accepts many arguments to it's constructor, and a subclass that should define one additional argument.
> > What's the most "pythonic" way to make this work?
> class BaseClass(object):
> def __init__(self, x, y, z, foo='foo'): # whatever
> # etc
> class SubClass(BaseClass):
> def __init__(self, t, *args, **kw):
> BaseClass.__init__(self, *args, **kw)
> # do something with t
> This does mean that the special sub class argument has to come before
> the base class arguments when you create instances.
> Whether you call BaseClass.__init__ early or late in the subclass init
> method could depend on what your classes are doing. Remember, in
> Python, __init__ only initializes objects, it doesn't create them.
> It's just another bit of code that you can call whenever you want.
> Tutor maillist - Tutor at python.org
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