Merge pull request #2198 from Markush2010/ticket21852

import datetime

import inspect

import decimal

import collections

from importlib import import_module

import os

import types

            if hasattr(value, "__module__"):

                module = value.__module__

                return "%s.%s" % (module, value.__name__), set(["import %s" % module])

        # Other iterables

        elif isinstance(value, collections.Iterable):

            imports = set()

            strings = []

            for item in value:

                item_string, item_imports = cls.serialize(item)

                imports.update(item_imports)

                strings.append(item_string)

            format = "(%s)" if len(strings) > 1 else "(%s,)"

            return format % (", ".join(strings)), imports

        # Uh oh.

        else:

            raise ValueError("Cannot serialize: %r\nThere are some values Django cannot serialize into migration files.\nFor more, see https://docs.djangoproject.com/en/dev/topics/migrations/#migration-serializing" % value)

                set(["from django.conf import settings"]),

            )

        )

        self.assertSerializedResultEqual(

            ((x, x*x) for x in range(3)),

            (

                "((0, 0), (1, 1), (2, 4))",

                set(),

            )

        )

    def test_simple_migration(self):

        """