Django: List field in model?

Question

In my model, I want a field that has a list of triplets. e.g. [[1, 3, 4], [4, 2, 6], [8, 12, 3], [3, 3, 9]]. Is there a field that can store this data in the da

Answer 1

I think it will help you.

from django.db import models
import ast

class ListField(models.TextField):
    __metaclass__ = models.SubfieldBase
    description = "Stores a python list"

    def __init__(self, *args, **kwargs):
        super(ListField, self).__init__(*args, **kwargs)

    def to_python(self, value):
        if not value:
            value = []

        if isinstance(value, list):
            return value

        return ast.literal_eval(value)

    def get_prep_value(self, value):
        if value is None:
            return value

        return unicode(value)

    def value_to_string(self, obj):
        value = self._get_val_from_obj(obj)
        return self.get_db_prep_value(value)

class ListModel(models.Model):
    test_list = ListField()

Example :

>>> ListModel.objects.create(test_list= [[1,2,3], [2,3,4,4]])

>>> ListModel.objects.get(id=1)

>>> o = ListModel.objects.get(id=1)
>>> o.id
1L
>>> o.test_list
[[1, 2, 3], [2, 3, 4, 4]]
>>>