Allow acces to instance columns as if it is a dict.

changelog

@@ -8,6 +8,7 @@ CHANGELOG
 * clear TTL and timestamp off models after persisting to DB
 * allows UUID without - (Thanks to Michael Haddad, github.com/mahall)
 * fixes regarding syncing schema settings (thanks Kai Lautaportti github.com/dokai)
+* allow acces to instance columns as if it is a dict
 
 0.10.0
 

cqlengine/models.py

@@ -421,6 +421,37 @@ class BaseModel(object):
             val = col.validate(getattr(self, name))
             setattr(self, name, val)
 
+    ### Let an instance be used like a dict of its columns keys/values
+
+    def __iter__(self):
+        """ Iterate over column ids. """
+        for column_id in self._columns.keys():
+            yield column_id
+
+    def __getitem__(self, key):
+        """ Returns column's value. """
+        if not isinstance(key, basestring):
+            raise TypeError
+        if key not in self._columns.keys():
+            raise KeyError
+        return getattr(self, key)
+
+    def __len__(self):
+        """ Returns the number of columns defined on that model. """
+        return len(self._columns.keys())
+
+    def keys(self):
+        """ Returns list of column's IDs. """
+        return [k for k in self]
+
+    def values(self):
+        """ Returns list of column's values. """
+        return [self[k] for k in self]
+
+    def items(self):
+        """ Returns a dictionnary of columns's IDs/values. """
+        return [(k, self[k]) for k in self]
+
     def _as_dict(self):
         """ Returns a map of column names to cleaned values """
         values = self._dynamic_columns or {}

cqlengine/tests/model/test_model_io.py

@@ -1,6 +1,7 @@
 from uuid import uuid4
 import random
 from datetime import date
+from operator import itemgetter
 from cqlengine.tests.base import BaseCassEngTestCase
 
 from cqlengine.management import create_table
@@ -43,6 +44,26 @@ class TestModelIO(BaseCassEngTestCase):
         for cname in tm._columns.keys():
             self.assertEquals(getattr(tm, cname), getattr(tm2, cname))
 
+    def test_model_read_as_dict(self):
+        """
+        Tests that columns of an instance can be read as a dict.
+        """
+        tm = TestModel.create(count=8, text='123456789', a_bool=True)
+        column_dict = {
+            'id': tm.id,
+            'count': tm.count,
+            'text': tm.text,
+            'a_bool': tm.a_bool,
+        }
+        self.assertEquals(sorted(tm.keys()), sorted(column_dict.keys()))
+        self.assertEquals(sorted(tm.values()), sorted(column_dict.values()))
+        self.assertEquals(
+            sorted(tm.items(), key=itemgetter(0)),
+            sorted(column_dict.items(), key=itemgetter(0)))
+        self.assertEquals(len(tm), len(column_dict))
+        for column_id in column_dict.keys():
+            self.assertEqual(tm[column_id], column_dict[column_id])
+
     def test_model_updating_works_properly(self):
         """
         Tests that subsequent saves after initial model creation work