class for model choices

Question

How can I use a class for choices of a model in Django?

Here is kind of what I want:

class ChoicesCls(object):
    def __init__(self):
        self.OPTION_ONE = 'O1'
        self.OPTION_ONE_SHORT = 'Opt 1'
        self.OPTION_ONE_LONG = 'Option 1'
        self.OPTION_TWO = 'O2'
        self.OPTION_TWO_SHORT = 'Opt 2'
        self.OPTION_TWO_LONG = 'Option 2'

    def get_choices(self):
        return (
            (self.OPTION_ONE, self.OPTION_ONE_LONG),
            (self.OPTION_TWO, self.OPTION_TWO_LONG)
        )


class TestModel(models.Model):
    choices_obj = ChoicesCls()
    field = models.CharField(choices=choices_obj.get_choices)

The main reason I want something like this is so in another place I can do something like

option = "ONE"
getattr(TestModel.choices_obj, "OPTION_{}_SHORT".format(option))

Answer 1

Try something like this

class FakeChoices:
    def __init__(self):
        self.OPTION_ONE = 'O1'
        self.OPTION_ONE_SHORT = 'Opt 1'
        self.OPTION_ONE_LONG = 'Option 1'
        self.OPTION_TWO = 'O2'
        self.OPTION_TWO_SHORT = 'Opt 2'
        self.OPTION_TWO_LONG = 'Option 2'

    def __get_tuple(self):
        return (
            (self.OPTION_ONE, self.OPTION_ONE_LONG),
            (self.OPTION_TWO, self.OPTION_TWO_LONG)
        )

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

    def __iter__(self):
        return iter(self.__get_tuple())

...

class TestModel(models.Model):
    field = models.CharField(choices=FakeChoices())

As you might imagine you can put all sorts of crazy logic inside FakeChoices class. And you should be able to do

option = "ONE"
getattr(TestModel._meta.get_field('field').choices, "OPTION_{}_SHORT".format(option))