[Tutor] __init__() - is it required?

[bob gailer]

On 1/9/2011 4:42 PM, Alan Gauld wrote:
>
> "Corey Richardson" <kb1pkl at aim.com> wrote
>
>> Do all classes need an __init__() method? I have classes that look much
>> like this one starts out:
>
> No, init() is only for initialising the object instance.
> If you have no local instance spwecific initialisation
> you can leave it to the inherited init() aor have no init()
> at all.

Well I'd like to expand that a bit. There are cases where I create a 
class attribute and update it each time an instance is created. O

>
> OTOH If you do have no need for an init it implies you
> probably have no instance variables, which is somewhat unusual.
> Not unheard of - you may only be modifying the behaviour of an
> inherited class - but it is unusual.
>
>> class GenerateXML(object):
>>    """Defines methods to be inherited for StaticXML and AnimationXML"""
>>    def __init__(self):
>>        pass
>
>
> IN this case it is a waste of time. It could even do harm in cases
> where you ingherit from a superclass that does have an init()
> since the pass will mean it never gets called! Whereas if you
> omit the init() the suiperclass init(if it exists) will get called.
>
> HTH,
>
>


-- 
Bob Gailer
919-636-4239
Chapel Hill NC