macaronikazoo <macaronikazoo@gmail.comwrites:
Quote:
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
