Passing arguments to subclasses

[Bruno Desthuilliers]

John Dann a écrit :
> May I ask a simple newbie question, which I presume is true, but for
> which I can't readily find confirmation:
> 
> Let's say I have a parent class with an __init__ method explicitly
> defined:
> 
> class ParentClass(object):
> 	def __init__(self, keyword1, keyword2):
> 		etc
> 
> and I subclass this:
> 
> class ChildClass(ParentClass):
> 	# No __init__ method explicitly defined
> 
> Now I presume that I can instantiate a child object as:
> 
> child = ChildClass(arg1, arg2)
> 
> and arg1, arg2 will be passed through to the 'constructor' of the
> antecedent ParentClass (there being no overrriding __init__ method
> defined for ChildClass) and mapping to keyword1, keyword2 etc.
> 
> Have I understood this correctly?

Yes. But you could have checked by yourself:

bruno at bruno:~$ python
Python 2.5.1 (r251:54863, Mar  7 2008, 03:41:45)
[GCC 4.1.2 (Ubuntu 4.1.2-0ubuntu4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
 >>> class Parent(object):
...     def __init__(self, kw1, kw2):
...             print self, kw1, kw2
...             self.kw1, self.kw2 = kw1, kw2
...
 >>> class Child(Parent): pass
...
 >>> c = Child("arg1", "arg2")
<__main__.Child object at 0xb7ddeccc> arg1 arg2
 >>> c.kw1
'arg1'
 >>> c.kw2
'arg2'
 >>>

HTH