Fixed #20094 - Be more careful when checking for Iterator

Python 2.6 has some different behaviour when checking
isinstance(foo, collections.Iterator).

1 files changed, 2 insertions, 2 deletions

diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py
index c210cfabf6..1f0ce5e4ed 100644
--- a/django/db/models/fields/__init__.py
+++ b/django/db/models/fields/__init__.py
@@ -1,6 +1,5 @@
 from __future__ import unicode_literals
 
-import collections
 import copy
 import datetime
 import decimal
@@ -18,6 +17,7 @@ from django.core import exceptions, validators
 from django.utils.datastructures import DictWrapper
 from django.utils.dateparse import parse_date, parse_datetime, parse_time
 from django.utils.functional import curry, total_ordering
+from django.utils.itercompat import is_iterator
 from django.utils.text import capfirst
 from django.utils import timezone
 from django.utils.translation import ugettext_lazy as _
@@ -488,7 +488,7 @@ class Field(object):
         return bound_field_class(self, fieldmapping, original)
 
     def _get_choices(self):
-        if isinstance(self._choices, collections.Iterator):
+        if is_iterator(self._choices):
             choices, self._choices = tee(self._choices)
             return choices
         else: