macaronikazoo <[EMAIL PROTECTED]> writes:
> i'm having a hell of a time getting this to work. basically I want to
> be able to instantiate an object using either a list, or a string, but
> the class inherits from list.
>
> if the class is instantiated with a string, then run a method over it
> to tokenize it in a meaningful way.
>
> so how come this doesn't work??? if I do this:
>
> a=TMP( 'some string' )
>
> it does nothing more than list('some string') and seems to be ignoring
> the custom __new__ method.
>
>
>
> def convertDataToList( data ): return [1,2,3]
> class TMP(list):
> def __new__( cls, data ):
> if isinstance(data, basestring):
> new = convertDataToList( data )
> return list.__new__( cls, new )
>
> if isinstance(data, list):
> return list.__new__( cls, data )
A list is mutable, its initialisation is done in __init__() not
__new__(). There was a recent post about this (in the last couple of
weeks).
--
Arnaud
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