Replaced 'next' testing by collections.Iterator testing.

The new construct is also Python 3 compatible (where 'next' has
been renamed to '__next__').

1 files changed, 2 insertions, 1 deletions

diff --git a/django/db/models/sql/where.py b/django/db/models/sql/where.py
index 0bc3638b80..5515bc4f83 100644
--- a/django/db/models/sql/where.py
+++ b/django/db/models/sql/where.py
@@ -4,6 +4,7 @@ Code to manage the creation and SQL rendering of 'where' constraints.
 
 from __future__ import absolute_import
 
+import collections
 import datetime
 from itertools import repeat
 
@@ -49,7 +50,7 @@ class WhereNode(tree.Node):
             return
 
         obj, lookup_type, value = data
-        if hasattr(value, '__iter__') and hasattr(value, 'next'):
+        if isinstance(value, collections.Iterator):
             # Consume any generators immediately, so that we can determine
             # emptiness and transform any non-empty values correctly.
             value = list(value)