Default method arguments

[Bengt Richter]

On Tue, 15 Nov 2005 23:51:18 +0100, "Fredrik Lundh" <fredrik at pythonware.com> wrote:

>Steven D'Aprano wrote:
>
>>> Another solution to this is the use of a 'marker' object and identity test:
>>>
>>> _marker = []
>>> class A(object):
>>>     def __init__(self, n):
>>>         self.data =n
>>>     def f(self, x = _marker):
>>>         if x is _marker:
>>>             x = self.data
>>>         print x
>>
>> I would like to see _marker put inside the class' scope. That prevents
>> somebody from the outside scope easily passing _marker as an argument to
>> instance.f.
>
>if you don't want people to be able to easily pass _marker as an argument
>to the f method, you probably shouldn't use it as the default value.
>
LOL ;-)

Regards,
Bengt Richter