Merge pull request #290 from nramirezuy/item-copy

added copy method to item

docs/topics/items.rst

@@ -157,6 +157,10 @@ Copying items::
     >>> print product2
     Product(name='Desktop PC', price=1000)
 
+    >>> product3 = product2.copy()
+    >>> print product3
+    Product(name='Desktop PC', price=1000)
+
 Creating dicts from items::
 
     >>> dict(product) # create a dict from all populated values

scrapy/item.py

@@ -4,6 +4,7 @@ Scrapy Item
 See documentation in docs/topics/item.rst
 """
 
+from copy import deepcopy
 from pprint import pformat
 from UserDict import DictMixin
 
@@ -76,6 +77,9 @@ class DictItem(DictMixin, BaseItem):
     def __repr__(self):
         return pformat(dict(self))
 
+    def copy(self):
+        return self.__class__(self)
+
 
 class Item(DictItem):
 

scrapy/tests/test_item.py

@@ -98,8 +98,8 @@ class ItemTest(unittest.TestCase):
     def test_metaclass(self):
         class TestItem(Item):
             name = Field()
-            keys = Field() 
-            values = Field() 
+            keys = Field()
+            values = Field()
 
         i = TestItem()
         i['name'] = u'John'
@@ -114,8 +114,8 @@ class ItemTest(unittest.TestCase):
     def test_metaclass_inheritance(self):
         class BaseItem(Item):
             name = Field()
-            keys = Field() 
-            values = Field() 
+            keys = Field()
+            values = Field()
 
         class TestItem(BaseItem):
             keys = Field()
@@ -133,6 +133,15 @@ class ItemTest(unittest.TestCase):
         i['name'] = u'John'
         self.assertEqual(dict(i), {'name': u'John'})
 
+    def test_copy(self):
+        class TestItem(Item):
+            name = Field()
+        item = TestItem({'name':'lower'})
+        copied_item = item.copy()
+        self.assertNotEqual(id(item), id(copied_item))
+        copied_item['name'] = copied_item['name'].upper()
+        self.assertNotEqual(item['name'], copied_item['name'])
+
 
 if __name__ == "__main__":
     unittest.main()