id summary reporter owner description type status component version severity resolution keywords cc stage has_patch needs_docs needs_tests needs_better_patch easy ui_ux 26026 EmptyQuerySet isinstance check broken with not QuerySet datatypes Vladimir Prokhoda Anderson Resende "isinstance check on any instance, that is not QuerySet (actually anything without .query attribute) and django.db.models.query.EmptyQuerySet throws AttributeError. Code to reproduce. {{{ In [9]: from django.db.models.query import EmptyQuerySet In [10]: isinstance(1, EmptyQuerySet) --------------------------------------------------------------------------- AttributeError Traceback (most recent call last) in () ----> 1 isinstance(1, EmptyQuerySet) /home/vprokhoda/Envs/ADMIN2/local/lib/python2.7/site-packages/django/db/models/query.pyc in __instancecheck__(self, instance) 1171 class InstanceCheckMeta(type): 1172 def __instancecheck__(self, instance): -> 1173 return instance.query.is_empty() 1174 1175 AttributeError: 'int' object has no attribute 'query' In [11]: In [11]: import django In [12]: django.__version__ Out[12]: '1.9' }}} Quick and dirty fix is {{{ (django)vprokhoda@tests$ git diff diff --git a/django/db/models/query.py b/django/db/models/query.py index 45c0320..0cc5f94 100644 --- a/django/db/models/query.py +++ b/django/db/models/query.py @@ -1171,7 +1171,7 @@ class QuerySet(object): class InstanceCheckMeta(type): def __instancecheck__(self, instance): - return instance.query.is_empty() + return hasattr(instance, 'query') and instance.query.is_empty() }}} " Bug closed Database layer (models, ORM) dev Normal fixed Accepted 1 0 0 0 1 0