Access class hierarchy attribute

Question

Given a class named DataStream

class DataStream(object):
    def __init__(self):
        self.start = start
        self.input_val = input_val

and a class named InDataStream:

class  InDataStream(DataStream):
    def __init__(self):
        super( InDataStream, self).__init__()
        self.ready = ready

stream = InDataStream()

I want to send DataStream part of stream into a function, something like:

function(stream.DataStream)

Is there any nice way to do this task?

That doesn't make any sense, `stream` (or any `InDataStream`) doesn't *have a* `DataStream`, it **is a** `DataStream`. — jonrsharpe, Jun 10 '16 at 22:15
Are you asking how to sort of downcast `InDataStream` to a `DataStream` and hide its `InDataStream` qualities? Why do you want to do this? This sounds like an [XY problem](http://meta.stackexchange.com/questions/66377/what-is-the-xy-problem) — rrauenza, Jun 10 '16 at 22:20
I kind of want to use `indatastream` like a `datastream` by neglecting its `ready` attribute. I want to send indatastream's datastream part into a function. — vikram9866, Jun 11 '16 at 21:36

score 0 · Answer 1 · edited Jun 10 '16 at 22:23

0

If you're looking to access an instance of DataStream from an instance of class InDataStream, then you may consider using composition instead of inheritance:

class InDataStream(object):
    def __init__(self):
        self.ready = ready
        self.datastream = DataStream()

Then you can do:

stream = InDataStream()
function(stream.datastream)

edited Jun 10 '16 at 22:23

jonrsharpe

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answered Jun 10 '16 at 22:18

Moses Koledoye

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Thanks ... I completely overlooked that I was missing that ... It's solved :) – vikram9866 Jun 10 '16 at 22:20
Is there anyway this can be achieved without changing the class structure ? – vikram9866 Jun 11 '16 at 21:33

Access class hierarchy attribute

1 Answers1