Fix use of is and is not vs. ==

polymorphic/base.py

@@ -73,7 +73,7 @@ def __new__(self, model_name, bases, attrs, **kwargs):
         # determine the name of the primary key field and store it into the class variable
         # polymorphic_primary_key_name (it is needed by query.py)
         for f in new_class._meta.fields:
-            if f.primary_key and type(f) != models.OneToOneField:
+            if f.primary_key and type(f) is not models.OneToOneField:
                 new_class.polymorphic_primary_key_name = f.name
                 break
 

polymorphic/query.py

@@ -267,7 +267,7 @@ def tree_node_test___lookup(my_model, node):
                     for i in range(len(node.children)):
                         child = node.children[i]
 
-                        if type(child) == tuple:
+                        if type(child) is tuple:
                             # this Q object child is a tuple => a kwarg like Q( instance_of=ModelB )
                             assert "___" not in child[0], ___lookup_assert_msg
                         else:

polymorphic/showfields.py

@@ -62,7 +62,7 @@ def _showfields_add_regular_fields(self, parts):
             out = field.name
 
             # if this is the standard primary key named "id", print it as we did with older versions of django_polymorphic
-            if field.primary_key and field.name == "id" and type(field) == models.AutoField:
+            if field.primary_key and field.name == "id" and type(field) is models.AutoField:
                 out += f" {getattr(self, field.name)}"
 
             # otherwise, display it just like all other fields (with correct type, shortened content etc.)