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from functools import partial
import pytest
from itemloaders import ItemLoader
from itemloaders.processors import Compose, Identity, Join, MapCompose, TakeFirst
class CustomItemLoader(ItemLoader):
name_in = MapCompose(lambda v: v.title())
class DefaultedItemLoader(ItemLoader):
default_input_processor = MapCompose(lambda v: v[:-1])
# test processors
def processor_with_args(value, other=None, loader_context=None):
if "key" in loader_context:
return loader_context["key"]
return value
class TestItemLoaderBasic:
def test_load_item_using_default_loader(self):
i = {"summary": "lala"}
il = ItemLoader(item=i)
il.add_value("name", "marta")
item = il.load_item()
assert item is i
assert item["summary"] == ["lala"]
assert item["name"] == ["marta"]
def test_load_item_using_custom_loader(self):
il = CustomItemLoader()
il.add_value("name", "marta")
item = il.load_item()
assert item["name"] == ["Marta"]
def test_load_item_ignore_none_field_values(self):
def validate_sku(value):
# Let's assume a SKU is only digits.
if value.isdigit():
return value
return None
class MyLoader(ItemLoader):
name_out = Compose(lambda vs: vs[0]) # take first which allows empty values
price_out = Compose(TakeFirst(), float)
sku_out = Compose(TakeFirst(), validate_sku)
valid_fragment = "SKU: 1234"
invalid_fragment = "SKU: not available"
sku_re = "SKU: (.+)"
il = MyLoader(item={})
# Should not return "sku: None".
il.add_value("sku", [invalid_fragment], re=sku_re)
# Should not ignore empty values.
il.add_value("name", "")
il.add_value("price", ["0"])
assert il.load_item() == {"name": "", "price": 0.0}
il.replace_value("sku", [valid_fragment], re=sku_re)
assert il.load_item()["sku"] == "1234"
def test_self_referencing_loader(self):
class MyLoader(ItemLoader):
url_out = TakeFirst()
def img_url_out(self, values):
return (self.get_output_value("url") or "") + values[0]
il = MyLoader(item={})
il.add_value("url", "http://example.com/")
il.add_value("img_url", "1234.png")
assert il.load_item() == {
"url": "http://example.com/",
"img_url": "http://example.com/1234.png",
}
il = MyLoader(item={})
il.add_value("img_url", "1234.png")
assert il.load_item() == {"img_url": "1234.png"}
def test_add_value(self):
il = CustomItemLoader()
il.add_value("name", "marta")
assert il.get_collected_values("name") == ["Marta"]
assert il.get_output_value("name") == ["Marta"]
il.add_value("name", "pepe")
assert il.get_collected_values("name") == ["Marta", "Pepe"]
assert il.get_output_value("name") == ["Marta", "Pepe"]
# test add object value
il.add_value("summary", {"key": 1})
assert il.get_collected_values("summary") == [{"key": 1}]
il.add_value(None, "Jim", lambda x: {"name": x})
assert il.get_collected_values("name") == ["Marta", "Pepe", "Jim"]
def test_add_zero(self):
il = ItemLoader()
il.add_value("name", 0)
assert il.get_collected_values("name") == [0]
def test_add_none(self):
il = ItemLoader()
il.add_value("name", None)
assert il.get_collected_values("name") == []
def test_replace_value(self):
il = CustomItemLoader()
il.replace_value("name", "marta")
assert il.get_collected_values("name") == ["Marta"]
assert il.get_output_value("name") == ["Marta"]
il.replace_value("name", "pepe")
assert il.get_collected_values("name") == ["Pepe"]
assert il.get_output_value("name") == ["Pepe"]
il.replace_value(None, "Jim", lambda x: {"name": x})
assert il.get_collected_values("name") == ["Jim"]
def test_replace_value_none(self):
il = CustomItemLoader()
il.replace_value("name", None)
assert il.get_collected_values("name") == []
il.replace_value("name", "marta")
assert il.get_collected_values("name") == ["Marta"]
il.replace_value(
"name", None
) # when replacing with `None` nothing should happen
assert il.get_collected_values("name") == ["Marta"]
def test_get_value(self):
il = ItemLoader()
assert il.get_value(["foo", "bar"], TakeFirst(), str.upper) == "FOO"
assert il.get_value(["name:foo", "name:bar"], re="name:(.*)$") == ["foo", "bar"]
assert (
il.get_value(["name:foo", "name:bar"], TakeFirst(), re="name:(.*)$")
== "foo"
)
assert None is il.get_value(["foo", "bar"], TakeFirst(), re="name:(.*)$")
assert None is il.get_value(None, TakeFirst())
il.add_value("name", ["name:foo", "name:bar"], TakeFirst(), re="name:(.*)$")
assert il.get_collected_values("name") == ["foo"]
il.replace_value("name", "name:bar", re="name:(.*)$")
assert il.get_collected_values("name") == ["bar"]
def test_iter_on_input_processor_input(self):
class NameFirstItemLoader(ItemLoader):
name_in = TakeFirst()
il = NameFirstItemLoader()
il.add_value("name", "marta")
assert il.get_collected_values("name") == ["marta"]
il = NameFirstItemLoader()
il.add_value("name", ["marta", "jose"])
assert il.get_collected_values("name") == ["marta"]
il = NameFirstItemLoader()
il.replace_value("name", "marta")
assert il.get_collected_values("name") == ["marta"]
il = NameFirstItemLoader()
il.replace_value("name", ["marta", "jose"])
assert il.get_collected_values("name") == ["marta"]
il = NameFirstItemLoader()
il.add_value("name", "marta")
il.add_value("name", ["jose", "pedro"])
assert il.get_collected_values("name") == ["marta", "jose"]
def test_map_compose_filter(self):
def filter_world(x):
return None if x == "world" else x
proc = MapCompose(filter_world, str.upper)
assert proc(["hello", "world", "this", "is", "scrapy"]) == [
"HELLO",
"THIS",
"IS",
"SCRAPY",
]
def test_map_compose_filter_multil(self):
class CustomItemLoader(ItemLoader):
name_in = MapCompose(lambda v: v.title(), lambda v: v[:-1])
il = CustomItemLoader()
il.add_value("name", "marta")
assert il.get_output_value("name") == ["Mart"]
item = il.load_item()
assert item["name"] == ["Mart"]
def test_default_input_processor(self):
il = DefaultedItemLoader()
il.add_value("name", "marta")
assert il.get_output_value("name") == ["mart"]
def test_inherited_default_input_processor(self):
class InheritDefaultedItemLoader(DefaultedItemLoader):
pass
il = InheritDefaultedItemLoader()
il.add_value("name", "marta")
assert il.get_output_value("name") == ["mart"]
def test_input_processor_inheritance(self):
class ChildItemLoader(CustomItemLoader):
url_in = MapCompose(lambda v: v.lower())
il = ChildItemLoader()
il.add_value("url", "HTTP://scrapy.ORG")
assert il.get_output_value("url") == ["http://scrapy.org"]
il.add_value("name", "marta")
assert il.get_output_value("name") == ["Marta"]
class ChildChildItemLoader(ChildItemLoader):
url_in = MapCompose(lambda v: v.upper())
summary_in = MapCompose(lambda v: v)
il = ChildChildItemLoader()
il.add_value("url", "http://scrapy.org")
assert il.get_output_value("url") == ["HTTP://SCRAPY.ORG"]
il.add_value("name", "marta")
assert il.get_output_value("name") == ["Marta"]
def test_empty_map_compose(self):
class IdentityDefaultedItemLoader(DefaultedItemLoader):
name_in = MapCompose()
il = IdentityDefaultedItemLoader()
il.add_value("name", "marta")
assert il.get_output_value("name") == ["marta"]
def test_identity_input_processor(self):
class IdentityDefaultedItemLoader(DefaultedItemLoader):
name_in = Identity()
il = IdentityDefaultedItemLoader()
il.add_value("name", "marta")
assert il.get_output_value("name") == ["marta"]
def test_extend_custom_input_processors(self):
class ChildItemLoader(CustomItemLoader):
name_in = MapCompose(CustomItemLoader.name_in, str.swapcase)
il = ChildItemLoader()
il.add_value("name", "marta")
assert il.get_output_value("name") == ["mARTA"]
def test_extend_default_input_processors(self):
class ChildDefaultedItemLoader(DefaultedItemLoader):
name_in = MapCompose(
DefaultedItemLoader.default_input_processor, str.swapcase
)
il = ChildDefaultedItemLoader()
il.add_value("name", "marta")
assert il.get_output_value("name") == ["MART"]
def test_output_processor_using_function(self):
il = CustomItemLoader()
il.add_value("name", ["mar", "ta"])
assert il.get_output_value("name") == ["Mar", "Ta"]
class TakeFirstItemLoader(CustomItemLoader):
name_out = " ".join
il = TakeFirstItemLoader()
il.add_value("name", ["mar", "ta"])
assert il.get_output_value("name") == "Mar Ta"
def test_output_processor_error(self):
class CustomItemLoader(ItemLoader):
name_out = MapCompose(float)
il = CustomItemLoader()
il.add_value("name", ["$10"])
expected_exc = None
try:
float("$10")
except Exception as e:
expected_exc = e
exc = None
try:
il.load_item()
except Exception as e:
exc = e
assert isinstance(exc, ValueError)
s = str(exc)
assert "name" in s, s
assert "$10" in s, s
assert "ValueError" in s, s
assert str(expected_exc) in s, s
def test_output_processor_using_classes(self):
il = CustomItemLoader()
il.add_value("name", ["mar", "ta"])
assert il.get_output_value("name") == ["Mar", "Ta"]
class TakeFirstItemLoader1(CustomItemLoader):
name_out = Join()
il = TakeFirstItemLoader1()
il.add_value("name", ["mar", "ta"])
assert il.get_output_value("name") == "Mar Ta"
class TakeFirstItemLoader2(CustomItemLoader):
name_out = Join("<br>")
il = TakeFirstItemLoader2()
il.add_value("name", ["mar", "ta"])
assert il.get_output_value("name") == "Mar<br>Ta"
def test_default_output_processor(self):
il = CustomItemLoader()
il.add_value("name", ["mar", "ta"])
assert il.get_output_value("name") == ["Mar", "Ta"]
class LalaItemLoader(CustomItemLoader):
default_output_processor = Identity()
il = LalaItemLoader()
il.add_value("name", ["mar", "ta"])
assert il.get_output_value("name") == ["Mar", "Ta"]
def test_loader_context_on_declaration(self):
class ChildItemLoader(CustomItemLoader):
url_in = MapCompose(processor_with_args, key="val")
il = ChildItemLoader()
il.add_value("url", "text")
assert il.get_output_value("url") == ["val"]
il.replace_value("url", "text2")
assert il.get_output_value("url") == ["val"]
def test_loader_context_on_instantiation(self):
class ChildItemLoader(CustomItemLoader):
url_in = MapCompose(processor_with_args)
il = ChildItemLoader(key="val")
il.add_value("url", "text")
assert il.get_output_value("url") == ["val"]
il.replace_value("url", "text2")
assert il.get_output_value("url") == ["val"]
def test_loader_context_on_assign(self):
class ChildItemLoader(CustomItemLoader):
url_in = MapCompose(processor_with_args)
il = ChildItemLoader()
il.context["key"] = "val"
il.add_value("url", "text")
assert il.get_output_value("url") == ["val"]
il.replace_value("url", "text2")
assert il.get_output_value("url") == ["val"]
def test_item_passed_to_input_processor_functions(self):
def processor(value, loader_context):
return loader_context["item"]["name"]
class ChildItemLoader(CustomItemLoader):
url_in = MapCompose(processor)
it = {"name": "marta"}
il = ChildItemLoader(item=it)
il.add_value("url", "text")
assert il.get_output_value("url") == ["marta"]
il.replace_value("url", "text2")
assert il.get_output_value("url") == ["marta"]
# def test_add_value_on_unknown_field(self):
# il = CustomItemLoader()
# self.assertRaises(KeyError, il.add_value, 'wrong_field', ['lala', 'lolo'])
def test_compose_processor(self):
class CustomItemLoader(ItemLoader):
name_out = Compose(lambda v: v[0], lambda v: v.title(), lambda v: v[:-1])
il = CustomItemLoader()
il.add_value("name", ["marta", "other"])
assert il.get_output_value("name") == "Mart"
item = il.load_item()
assert item["name"] == "Mart"
def test_partial_processor(self):
def join(values, sep=None, loader_context=None, ignored=None):
if sep is not None:
return sep.join(values)
if loader_context and "sep" in loader_context:
return loader_context["sep"].join(values)
return "".join(values)
class CustomItemLoader(ItemLoader):
name_out = Compose(partial(join, sep="+"))
url_out = Compose(partial(join, loader_context={"sep": "."}))
summary_out = Compose(partial(join, ignored="foo"))
il = CustomItemLoader()
il.add_value("name", ["rabbit", "hole"])
il.add_value("url", ["rabbit", "hole"])
il.add_value("summary", ["rabbit", "hole"])
item = il.load_item()
assert item["name"] == "rabbit+hole"
assert item["url"] == "rabbit.hole"
assert item["summary"] == "rabbithole"
def test_error_input_processor(self):
class CustomItemLoader(ItemLoader):
name_in = MapCompose(float)
il = CustomItemLoader()
with pytest.raises(
ValueError,
match=r"Error with input processor MapCompose: .* "
r"error='ValueError: Error in MapCompose .* "
r"error='ValueError: could not convert",
):
il.add_value("name", ["marta", "other"])
def test_error_output_processor(self):
class CustomItemLoader(ItemLoader):
name_out = Compose(Join(), float)
il = CustomItemLoader()
il.add_value("name", "marta")
with pytest.raises(
ValueError,
match=r"Error with output processor: .* "
r"error='ValueError: Error in Compose .* "
r"error='ValueError: could not convert",
):
il.load_item()
def test_error_processor_as_argument(self):
il = CustomItemLoader()
with pytest.raises(
ValueError,
match=r"Error with processor Compose .* "
r"error='ValueError: Error in Compose .* "
r"error='TypeError: float\(\) argument",
):
il.add_value("name", ["marta", "other"], Compose(float))
def test_get_unset_value(self):
loader = ItemLoader()
assert loader.load_item() == {}
assert loader.get_output_value("foo") == []
assert loader.load_item() == {}
class BaseNoInputReprocessingLoader(ItemLoader):
title_in = MapCompose(str.upper)
title_out = TakeFirst()
class NoInputReprocessingDictLoader(BaseNoInputReprocessingLoader):
default_item_class = dict
class TestNoInputReprocessingFromDict:
"""
Loaders initialized from loaded items must not reprocess fields (dict instances)
"""
def test_avoid_reprocessing_with_initial_values_single(self):
il = NoInputReprocessingDictLoader(item={"title": "foo"})
il_loaded = il.load_item()
assert il_loaded == {"title": "foo"}
assert NoInputReprocessingDictLoader(item=il_loaded).load_item() == {
"title": "foo"
}
def test_avoid_reprocessing_with_initial_values_list(self):
il = NoInputReprocessingDictLoader(item={"title": ["foo", "bar"]})
il_loaded = il.load_item()
assert il_loaded == {"title": "foo"}
assert NoInputReprocessingDictLoader(item=il_loaded).load_item() == {
"title": "foo"
}
def test_avoid_reprocessing_without_initial_values_single(self):
il = NoInputReprocessingDictLoader()
il.add_value("title", "foo")
il_loaded = il.load_item()
assert il_loaded == {"title": "FOO"}
assert NoInputReprocessingDictLoader(item=il_loaded).load_item() == {
"title": "FOO"
}
def test_avoid_reprocessing_without_initial_values_list(self):
il = NoInputReprocessingDictLoader()
il.add_value("title", ["foo", "bar"])
il_loaded = il.load_item()
assert il_loaded == {"title": "FOO"}
assert NoInputReprocessingDictLoader(item=il_loaded).load_item() == {
"title": "FOO"
}
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