Why no list heritable type?
Robert Brewer
fumanchu at amor.org
Thu Dec 16 15:55:41 EST 2004
James Stroud wrote:
> The thread "why not arrays" got me thinking. I would really
> like to inherit
> from a list so that I can add methods based on its contents,
> say if I filled
> it with a type of object and wanted to iterate over all
> objects. I have built
> a wrapper around a list like this for general use:
>
> class list_of_objects:
> def __init__(self):
> self.data = []
> def __len__(self):
> return len(self.data)
> etc ...
>
> Then it can be heritable and I can add or override methods.
> Why aren't built
> in lists and dictionaries real heritable types that can save
> this kind of patchwork?
They are since Python 2.2 (IIRC):
class mylist(list):
def mymethod(self):
self.x = 5
...etc.
What problems are you running into?
FuManChu
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