Way to iterate though object in python

Question

Is there a way in python to get data from object like this:

box = BoxWithOranges()
print box['color']
print box['weight']
print box['count']

And more compliant:

for index in range(box['count']):
    box[index].eat()

Are you looking for something like this? http://stackoverflow.com/questions/2675028/list-attributes-of-an-object — user3445972, Oct 01 '15 at 12:20
@marmeladze I think it's from some module because dict doesn't have `.eat()` method... — Remi Guan, Oct 01 '15 at 12:21
It looks as if it is a container that has it's own attributes and also contains a list of items (oranges). — neil, Oct 01 '15 at 12:22
It's not wholly clear what you're asking, but I suspect your answer lies in the [data model](https://docs.python.org/2/reference/datamodel.html). — jonrsharpe, Oct 01 '15 at 12:23
Please post the definition of `BoxWithOranges` or explain more clearly what you're trying to do. — bruno desthuilliers, Oct 01 '15 at 12:24
maybe this would be helpful - http://stackoverflow.com/a/34452/4481312 — marmeladze, Oct 01 '15 at 12:29

score 2 · Accepted Answer · answered Oct 01 '15 at 12:20

You'd have to implement the __getitem__ and __setitem__ methods for your class. That is what would be invoked when you used the [] operator. For example you could have the class keep a dict internally

class BoxWithOranges:
    def __init__(self):
        self.attributes = {}

    def __getitem__(self, key):
        return self.attributes[key]

    def __setitem__(self, key, value):
        self.attributes[key] = value

Demo

>>> box = BoxWithOranges()
>>> box['color'] = 'red'
>>> box['weight'] = 10.0
>>> print(box['color'])
red
>>> print(box['weight'])
10.0

I think the key is it needs to take an index or a dictionary key. I wonder if that means in `__getitem__` and `__setitem__` distinguishing between integers and strings. — neil, Oct 01 '15 at 13:08

Way to iterate though object in python

1 Answers1