Ticket #2265: iterator_choices.patch

django/db/models/fields/__init__.py

@@ -7 +7 @@
 from django.utils.functional import curry, lazy
 from django.utils.text import capfirst
 from django.utils.translation import gettext, gettext_lazy, ngettext
-import datetime, os, time
+import datetime, os, time, itertools
 
 class NOT_PROVIDED:
     pass
@@ -80 +80 @@
         self.prepopulate_from = prepopulate_from
         self.unique_for_date, self.unique_for_month = unique_for_date, unique_for_month
         self.unique_for_year = unique_for_year
-        self.choices = choices or []
+        self._choices = choices or []
         self.radio_admin = radio_admin
         self.help_text = help_text
         self.db_column = db_column
@@ -321 +321 @@
     def bind(self, fieldmapping, original, bound_field_class):
         return bound_field_class(self, fieldmapping, original)
 
+    def _get_choices(self):
+        if hasattr(self._choices, 'next'):
+            choices, self._choices = itertools.tee(self._choices, 2)
+        else:
+            choices = self._choices
+
+        return choices
+    choices = property(_get_choices)
+
 class AutoField(Field):
     empty_strings_allowed = False
     def __init__(self, *args, **kwargs):