diff --git a/scrapy/contrib/loader/processor.py b/scrapy/contrib/loader/processor.py
index bf8a355e9..8c74c5358 100644
--- a/scrapy/contrib/loader/processor.py
+++ b/scrapy/contrib/loader/processor.py
@@ -13,7 +13,7 @@ class MapCompose(object):
def __init__(self, *functions, **default_loader_context):
self.functions = functions
self.default_loader_context = default_loader_context
-
+
def __call__(self, value, loader_context=None):
values = arg_to_iter(value)
if loader_context:
@@ -35,7 +35,7 @@ class Compose(object):
self.functions = functions
self.stop_on_none = default_loader_context.get('stop_on_none', True)
self.default_loader_context = default_loader_context
-
+
def __call__(self, value, loader_context=None):
if loader_context:
context = MergeDict(loader_context, self.default_loader_context)
@@ -53,7 +53,7 @@ class TakeFirst(object):
def __call__(self, values):
for value in values:
- if value:
+ if value is not None and value != '':
return value
diff --git a/scrapy/tests/test_contrib_loader.py b/scrapy/tests/test_contrib_loader.py
index e306b7333..80f3151da 100644
--- a/scrapy/tests/test_contrib_loader.py
+++ b/scrapy/tests/test_contrib_loader.py
@@ -7,33 +7,37 @@ from scrapy.item import Item, Field
from scrapy.selector import HtmlXPathSelector
from scrapy.http import HtmlResponse
-# test items
+# test items
class NameItem(Item):
name = Field()
+
class TestItem(NameItem):
url = Field()
summary = Field()
-# test item loaders
+# test item loaders
class NameItemLoader(ItemLoader):
default_item_class = TestItem
+
class TestItemLoader(NameItemLoader):
name_in = MapCompose(lambda v: v.title())
+
class DefaultedItemLoader(NameItemLoader):
default_input_processor = MapCompose(lambda v: v[:-1])
-# test processors
+# test processors
def processor_with_args(value, other=None, loader_context=None):
if 'key' in loader_context:
return loader_context['key']
return value
+
class ItemLoaderTest(unittest.TestCase):
def test_load_item_using_default_loader(self):
@@ -96,7 +100,6 @@ class ItemLoaderTest(unittest.TestCase):
il.replace_value('name', u'name:bar', re=u'name:(.*)$')
self.assertEqual([u'bar'], il.get_collected_values('name'))
-
def test_iter_on_input_processor_input(self):
class NameFirstItemLoader(NameItemLoader):
name_in = TakeFirst()
@@ -215,7 +218,6 @@ class ItemLoaderTest(unittest.TestCase):
il.add_value('name', [u'mar', u'ta'])
self.assertEqual(il.get_output_value('name'), u'Mar Ta')
-
def test_output_processor_error(self):
class TestItemLoader(ItemLoader):
default_item_class = TestItem
@@ -240,7 +242,6 @@ class ItemLoaderTest(unittest.TestCase):
assert 'ValueError' in s, s
assert expected_exc_str in s, s
-
def test_output_processor_using_classes(self):
il = TestItemLoader()
il.add_value('name', [u'mar', u'ta'])
@@ -331,11 +332,13 @@ class ItemLoaderTest(unittest.TestCase):
item = il.load_item()
self.assertEqual(item['name'], u'Mart')
+
class ProcessorsTest(unittest.TestCase):
def test_take_first(self):
proc = TakeFirst()
self.assertEqual(proc([None, '', 'hello', 'world']), 'hello')
+ self.assertEqual(proc([None, '', 0, 'hello', 'world']), 0)
def test_identity(self):
proc = Identity()
@@ -363,10 +366,12 @@ class ProcessorsTest(unittest.TestCase):
self.assertEqual(proc([u'hello', u'world', u'this', u'is', u'scrapy']),
[u'HELLO', u'THIS', u'IS', u'SCRAPY'])
+
class TestXPathItemLoader(XPathItemLoader):
default_item_class = TestItem
name_in = MapCompose(lambda v: v.title())
+
class XPathItemLoaderTest(unittest.TestCase):
response = HtmlResponse(url="", body='marta
paragraph
')
@@ -428,4 +433,3 @@ class XPathItemLoaderTest(unittest.TestCase):
if __name__ == "__main__":
unittest.main()
-