Python class __init__(mandatory arguments?)

[Tom Hanks]

Lee John Moore <leej at dsl.pipex.com> wrote in message news:<bcitu2$jrrv8$1 at ID-129053.news.dfncis.de>...
> Just for confirmation really: When I create a custom class, is
> it *really* true that def __init__() arguments can only ever be
> optional?  Eg:

Mr Moore,

No. In my experience __init__ arguments without default values
(or using the *args, **kwargs idiom) are required and not optional,
exactly like all other functions.

> 
> class MyClass:
> 	param1 = None
> 	param2 = None
> 	def __init__(self, param1, param2):
> 		param1 = self.param1
> 		param2 = self.param2
> 
> myinstance1 = MyClass()
> myinstance2 = MyClass("Hello", "World")
> [snip]
> 
> I'm really unhappy that myinstance1 is allowed.  ;-)

I would be unhappy too.                                 :-(
Luckily running your code under 2.2.1 I get a traceback :-)
  Traceback (most recent call last):
  ...
  TypeError: __init__() takes exactly 3 arguments (1 given)

I hope this info leaves you less confused than when you started...

Tom.