- use six library for iterating dictionaries.

- minor pep8.
- remove NotImplementedError for manager methods that modifies the database. This manager class inherits from the django default manager, and there is no reason not to be able to use it as the default manager for a model.

gcharts/__init__.py

@@ -1,7 +1,11 @@
 # -*- coding: utf-8 -*-
+
 import logging
+
 from django.db import models
 from django.db.models.query import QuerySet, ValuesQuerySet, ValuesListQuerySet
+from django.utils import six
+
 
 try:
     import gviz_api
@@ -56,7 +60,7 @@ def to_json(self, order=None, labels=None, formatting=None, properties=None):
         return self.get_query_set().to_json(order, labels, formatting, properties)
 
     def to_json_response(self, order=None, labels=None, formatting=None, properties=None,
-                     req_id=0, handler="google.visualization.Query.setResponse"):
+                         req_id=0, handler="google.visualization.Query.setResponse"):
         return self.get_query_set().to_json_response(order, labels, formatting, properties,
                                                      req_id, handler)
 
@@ -68,8 +72,9 @@ class GChartsQuerySet(QuerySet):
     """
     def __init__(self, *args, **kwargs):
         super(GChartsQuerySet, self).__init__(*args, **kwargs)
-
-    def javascript_field(self, field):
+
+    @staticmethod
+    def javascript_field(field):
         """
         Return the javascript data type for
         field
@@ -87,7 +92,7 @@ def javascript_field(self, field):
             ("TimeField"): "timeofday",
         }
 
-        for k, v in fields.iteritems():
+        for k, v in six.iteritems(fields):
             if field.get_internal_type() in k:
                 return v
         # Should never hit this
@@ -104,7 +109,7 @@ def formatting(self, fields, formatting):
         if not isinstance(formatting, dict):
             raise Exception("formatting must be a dict")
         for row in self.values(*fields):
-            for field, frmt in formatting.iteritems():
+            for field, frmt in six.iteritems(formatting):
                 val = row[field]
                 frmt_val = frmt.format(val)
                 row.update({field: (val, frmt_val)})
@@ -120,7 +125,7 @@ def table_description(self, labels=None):
         # resolve aggregates
         aggregates = getattr(self, "aggregate_names", None)
         if aggregates is not None:
-            for alias, aggregate_expr in self.query.aggregates.iteritems():
+            for alias, aggregate_expr in six.iteritems(self.query.aggregates):
                 label = labels.pop(alias, alias)
                 field_jstype = self.javascript_field(aggregate_expr.field)
                 table_description.update({alias: (field_jstype, label)})
@@ -131,28 +136,29 @@ def table_description(self, labels=None):
         extra = getattr(self, "extra_names", None)
         valid_jstypes = ("string", "number", "boolean", "date", "datetime", "timeofday")
         if extra is not None:
-            for alias in self.query.extra.iterkeys():
+            for alias in six.iterkeys(self.query.extra):
                 try:
                     descr = labels.pop(alias)
                     if not (isinstance(descr, dict) and len(descr) == 1):
                         raise Exception("Field description must be a dict and must contain exactly one element.")
                     field_jstype, label = descr.popitem()
                     if field_jstype not in valid_jstypes:
-                        raise Exception("Invalid javascript type. Valid types are %s." % \
+                        raise Exception("Invalid javascript type. Valid types are %s." %
                                         ", ".join(valid_jstypes))
                     table_description.update({alias: (field_jstype, label)})
                 except KeyError:
-                    raise KeyError("No label found for extra field '%s'. Extra field labels must be configured as: labels={'extra_name': {'javascript type', 'label'}}" % alias)
-                except Exception, e:
-                    raise e
-
+                    raise KeyError(
+                        "No label found for extra field '%s'. Extra field labels must be configured as: "
+                        "labels={'extra_name': {'javascript type', 'label'}}" % alias
+                    )
+
         # resolve other fields of interest
         fields = set(getattr(self, "_fields", [f.name for f in self.model._meta.fields]))
 
         # remove fields that has already been
         # put in the table_description
         def clean_parsed_fields():
-            for f in table_description.iterkeys():
+            for f in six.iterkeys(table_description):
                 if f in fields:
                     fields.remove(f)
         clean_parsed_fields()
@@ -182,7 +188,7 @@ def clean_parsed_fields():
 
         clean_parsed_fields()
         if fields:
-            logger.warning("Could not create table description for the following fields %s:" % \
+            logger.warning("Could not create table description for the following fields %s:" %
                            ", ".join(fields))
         return table_description
 
@@ -192,12 +198,10 @@ def values(self, *fields):
     def values_list(self, *fields, **kwargs):
         flat = kwargs.pop("flat", False)
         if kwargs:
-            raise TypeError("Unexpected keyword arguments to values_list: %s"
-                    % (kwargs.keys(),))
+            raise TypeError("Unexpected keyword arguments to values_list: %s" % (kwargs.keys(),))
         if flat and len(fields) > 1:
             raise TypeError("'flat' is not valid when values_list is called with more than one field.")
-        return self._clone(klass=GChartsValuesListQuerySet, setup=True, flat=flat,
-                _fields=fields)
+        return self._clone(klass=GChartsValuesListQuerySet, setup=True, flat=flat, _fields=fields)
 
     #
     # Methods which serialize data to various outputs.
@@ -357,7 +361,7 @@ def to_json(self, order=None, labels=None, formatting=None, properties=None):
         return data_table.ToJSon(columns_order=order)
 
     def to_json_response(self, order=None, labels=None, formatting=None, properties=None,
-                 req_id=0, handler="google.visualization.Query.setResponse"):
+                         req_id=0, handler="google.visualization.Query.setResponse"):
         """
         Does _not_ return a new QuerySet.
         Writes a table as a JSON response that can be returned as-is to a client.
@@ -388,29 +392,7 @@ def to_json_response(self, order=None, labels=None, formatting=None, properties=
         else:
             data = self.values(*fields)
         data_table = gviz_api.DataTable(table_descr, data, properties)
-        return data_table.ToJSonResponse(columns_order=order,
-                             req_id=req_id, response_handler=handler)
-
-    #
-    # Methods that modifies database are not allowed
-    #
-    def create(self, *kwargs):
-        raise NotImplementedError("GChartsQuerySet is not able to modify the database")
-
-    def bulk_create(self, objs):
-        raise NotImplementedError("GChartsQuerySet is not able to modify the database")
-
-    def get_or_create(self, *kwargs):
-        raise NotImplementedError("GChartsQuerySet is not able to modify the database")
-
-    def delete(self):
-        raise NotImplementedError("GChartsQuerySet is not able to modify the database")
-
-    def update(self, *kwargs):
-        raise NotImplementedError("GChartsQuerySet is not able to modify the database")
-
-    def _update(self, *kwargs):
-        raise NotImplementedError("GChartsQuerySet is not able to modify the database")
+        return data_table.ToJSonResponse(columns_order=order, req_id=req_id, response_handler=handler)
 
 
 class GChartsValuesQuerySet(GChartsQuerySet, ValuesQuerySet):