Inheriting from Python list object(type?)

Mangabasi mangabasi at gmail.com
Wed May 23 15:07:47 EDT 2007


On May 23, 1:43 pm, "Jerry Hill" <malaclyp... at gmail.com> wrote:
> On 23 May 2007 11:31:56 -0700, Mangabasi <mangab... at gmail.com> wrote:
>
> > When I modified this to:
>
> > class Point(list):
> >     def __init__(self,x,y):
> >         super(Point, self).__init__([x, y])
> >         self.x = x
> >         self.y = y
>
> > It worked.
>
> Are you sure?
>
> >>> p = Point(10, 20)
> >>> p
> [10, 20]
> >>> p.x
> 10
> >>> p.x = 15
> >>> p
> [10, 20]
> >>> p[0]
> 10
> >>> p.x
> 15
>
> That doesn't look like what you were asking for in the original post.
> I'm afraid I don't know anything about numpy arrays or what special
> attributes an object may need to be put into a numpy array though.
>
> --
> Jerry

This is the winner:

class Point(list):
    def __init__(self, x, y, z = 1):
        super(Point, self).__init__([x, y, z])
        self.x = x
        self.y = y
        self.z = z

    def __getattr__(self, name):
        if name == 'x':
            return self[0]
        elif name == 'y':
            return self[1]
        elif name == 'z':
            return self[2]
        else:
            return self.__dict__[name]


    def __setattr__(self, name, value):
        if name == 'x':
            self[0] = value
        elif name == 'y':
            self[1] = value
        elif name == 'z':
            self[2] = value
        else:
            self.__dict__[name] = value




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