more efficient Item implementation and added support for using custom methods (unittests included)

scrapy/contrib_exp/newitem/models.py

@@ -10,6 +10,7 @@ class _ItemMeta(type):
         for n, v in attrs.iteritems():
             if isinstance(v, BaseField):
                 cls.fields[n] = v
+                delattr(cls, n)
         return cls
 
 
@@ -38,17 +39,14 @@ class Item(ScrapedItem):
         else:
             raise AttributeError(name)
 
-    def __getattribute__(self, name):
-        if name.startswith('_') or name == 'fields':
-            return ScrapedItem.__getattribute__(self, name)
-        
-        if name in self.fields.keys():
+    def __getattr__(self, name):
+        try:
+            return self._values[name]
+        except KeyError:
             try:
-                return self._values[name]
-            except KeyError:
                 return self.fields[name].default
-        else:
-            raise AttributeError(name)
+            except KeyError:
+                raise AttributeError(name)
 
     def __repr__(self):
         """Generate a representation of this item that can be used to

scrapy/tests/test_newitem.py

@@ -85,6 +85,31 @@ class NewItemTest(unittest.TestCase):
         assert i2.name == 'John Doe'
         assert i2.number == 123
 
+    def test_private_attr(self):
+        class TestItem(Item):
+            name = fields.StringField()
+
+        i = TestItem()
+        i._private = 'test'
+        self.assertEqual(i._private, 'test')
+
+    def test_custom_methods(self):
+        class TestItem(Item):
+            name = fields.StringField()
+
+            def get_name(self):
+                return self.name
+
+            def change_name(self, name):
+                self.name = name
+
+        i = TestItem()
+        self.assertEqual(i.get_name(), None)
+        i.name = 'lala'
+        self.assertEqual(i.get_name(), 'lala')
+        i.change_name('other')
+        self.assertEqual(i.get_name(), 'other')
+
 
 class NewItemFieldsTest(unittest.TestCase):