githubmirror/scrapy

tests/test_loader.py
567 строк19 KB
Andrey Rakhmatullin
Deprecate ScrapyCommand.set_crawler(), remove/fix some dead code. (#7276)
24 мар 2026, 12:36
24 мар 2026, 12:369f46511
from __future__ import annotations

import dataclasses

import attr
import pytest
from itemadapter import ItemAdapter
from itemloaders.processors import Compose, Identity, MapCompose, TakeFirst

from scrapy.http import HtmlResponse, Response
from scrapy.item import Field, Item
from scrapy.loader import ItemLoader
from scrapy.selector import Selector


# test items
class NameItem(Item):
    name = Field()


class SummaryItem(NameItem):
    url = Field()
    summary = Field()


class NestedItem(Item):
    name = Field()
    name_div = Field()
    name_value = Field()

    url = Field()
    image = Field()


@attr.s
class AttrsNameItem:
    name = attr.ib(default="")


@dataclasses.dataclass
class NameDataClass:
    name: list = dataclasses.field(default_factory=list)


# test item loaders
class NameItemLoader(ItemLoader):
    default_item_class = SummaryItem


class NestedItemLoader(ItemLoader):
    default_item_class = NestedItem


class ProcessorItemLoader(NameItemLoader):
    name_in = MapCompose(lambda v: v.title())


class TestBasicItemLoader:
    def test_add_value_on_unknown_field(self):
        il = ProcessorItemLoader()
        with pytest.raises(KeyError):
            il.add_value("wrong_field", ["lala", "lolo"])

    def test_load_item_using_default_loader(self):
        i = SummaryItem()
        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 = ProcessorItemLoader()
        il.add_value("name", "marta")
        item = il.load_item()
        assert item["name"] == ["Marta"]


class InitializationTestMixin:
    item_class: type | None = None

    def test_keep_single_value(self):
        """Loaded item should contain values from the initial item"""
        input_item = self.item_class(name="foo")
        il = ItemLoader(item=input_item)
        loaded_item = il.load_item()
        assert isinstance(loaded_item, self.item_class)
        assert ItemAdapter(loaded_item).asdict() == {"name": ["foo"]}

    def test_keep_list(self):
        """Loaded item should contain values from the initial item"""
        input_item = self.item_class(name=["foo", "bar"])
        il = ItemLoader(item=input_item)
        loaded_item = il.load_item()
        assert isinstance(loaded_item, self.item_class)
        assert ItemAdapter(loaded_item).asdict() == {"name": ["foo", "bar"]}

    def test_add_value_singlevalue_singlevalue(self):
        """Values added after initialization should be appended"""
        input_item = self.item_class(name="foo")
        il = ItemLoader(item=input_item)
        il.add_value("name", "bar")
        loaded_item = il.load_item()
        assert isinstance(loaded_item, self.item_class)
        assert ItemAdapter(loaded_item).asdict() == {"name": ["foo", "bar"]}

    def test_add_value_singlevalue_list(self):
        """Values added after initialization should be appended"""
        input_item = self.item_class(name="foo")
        il = ItemLoader(item=input_item)
        il.add_value("name", ["item", "loader"])
        loaded_item = il.load_item()
        assert isinstance(loaded_item, self.item_class)
        assert ItemAdapter(loaded_item).asdict() == {"name": ["foo", "item", "loader"]}

    def test_add_value_list_singlevalue(self):
        """Values added after initialization should be appended"""
        input_item = self.item_class(name=["foo", "bar"])
        il = ItemLoader(item=input_item)
        il.add_value("name", "qwerty")
        loaded_item = il.load_item()
        assert isinstance(loaded_item, self.item_class)
        assert ItemAdapter(loaded_item).asdict() == {"name": ["foo", "bar", "qwerty"]}

    def test_add_value_list_list(self):
        """Values added after initialization should be appended"""
        input_item = self.item_class(name=["foo", "bar"])
        il = ItemLoader(item=input_item)
        il.add_value("name", ["item", "loader"])
        loaded_item = il.load_item()
        assert isinstance(loaded_item, self.item_class)
        assert ItemAdapter(loaded_item).asdict() == {
            "name": ["foo", "bar", "item", "loader"]
        }

    def test_get_output_value_singlevalue(self):
        """Getting output value must not remove value from item"""
        input_item = self.item_class(name="foo")
        il = ItemLoader(item=input_item)
        assert il.get_output_value("name") == ["foo"]
        loaded_item = il.load_item()
        assert isinstance(loaded_item, self.item_class)
        assert ItemAdapter(loaded_item).asdict() == {"name": ["foo"]}

    def test_get_output_value_list(self):
        """Getting output value must not remove value from item"""
        input_item = self.item_class(name=["foo", "bar"])
        il = ItemLoader(item=input_item)
        assert il.get_output_value("name") == ["foo", "bar"]
        loaded_item = il.load_item()
        assert isinstance(loaded_item, self.item_class)
        assert ItemAdapter(loaded_item).asdict() == {"name": ["foo", "bar"]}

    def test_values_single(self):
        """Values from initial item must be added to loader._values"""
        input_item = self.item_class(name="foo")
        il = ItemLoader(item=input_item)
        assert il._values.get("name") == ["foo"]

    def test_values_list(self):
        """Values from initial item must be added to loader._values"""
        input_item = self.item_class(name=["foo", "bar"])
        il = ItemLoader(item=input_item)
        assert il._values.get("name") == ["foo", "bar"]


class TestInitializationFromDict(InitializationTestMixin):
    item_class = dict


class TestInitializationFromItem(InitializationTestMixin):
    item_class = NameItem


class TestInitializationFromAttrsItem(InitializationTestMixin):
    item_class = AttrsNameItem


class TestInitializationFromDataClass(InitializationTestMixin):
    item_class = NameDataClass


class BaseNoInputReprocessingLoader(ItemLoader):
    title_in = MapCompose(str.upper)
    title_out = TakeFirst()


class NoInputReprocessingItem(Item):
    title = Field()


class NoInputReprocessingItemLoader(BaseNoInputReprocessingLoader):
    default_item_class = NoInputReprocessingItem


class TestNoInputReprocessingFromItem:
    """
    Loaders initialized from loaded items must not reprocess fields (Item instances)
    """

    def test_avoid_reprocessing_with_initial_values_single(self):
        il = NoInputReprocessingItemLoader(item=NoInputReprocessingItem(title="foo"))
        il_loaded = il.load_item()
        assert il_loaded == {"title": "foo"}
        assert NoInputReprocessingItemLoader(item=il_loaded).load_item() == {
            "title": "foo"
        }

    def test_avoid_reprocessing_with_initial_values_list(self):
        il = NoInputReprocessingItemLoader(
            item=NoInputReprocessingItem(title=["foo", "bar"])
        )
        il_loaded = il.load_item()
        assert il_loaded == {"title": "foo"}
        assert NoInputReprocessingItemLoader(item=il_loaded).load_item() == {
            "title": "foo"
        }

    def test_avoid_reprocessing_without_initial_values_single(self):
        il = NoInputReprocessingItemLoader()
        il.add_value("title", "FOO")
        il_loaded = il.load_item()
        assert il_loaded == {"title": "FOO"}
        assert NoInputReprocessingItemLoader(item=il_loaded).load_item() == {
            "title": "FOO"
        }

    def test_avoid_reprocessing_without_initial_values_list(self):
        il = NoInputReprocessingItemLoader()
        il.add_value("title", ["foo", "bar"])
        il_loaded = il.load_item()
        assert il_loaded == {"title": "FOO"}
        assert NoInputReprocessingItemLoader(item=il_loaded).load_item() == {
            "title": "FOO"
        }


class TestOutputProcessorItem:
    def test_output_processor(self):
        class TempItem(Item):
            temp = Field()

            def __init__(self, *args, **kwargs):
                super().__init__(self, *args, **kwargs)
                self.setdefault("temp", 0.3)

        class TempLoader(ItemLoader):
            default_item_class = TempItem
            default_input_processor = Identity()
            default_output_processor = Compose(TakeFirst())

        loader = TempLoader()
        item = loader.load_item()
        assert isinstance(item, TempItem)
        assert dict(item) == {"temp": 0.3}


class TestSelectortemLoader:
    response = HtmlResponse(
        url="",
        encoding="utf-8",
        body=b"""
    <html>
    <body>
    <div id="id">marta</div>
    <p>paragraph</p>
    <a href="http://www.scrapy.org">homepage</a>
    <img src="/images/logo.png" width="244" height="65" alt="Scrapy">
    </body>
    </html>
    """,
    )

    def test_init_method(self):
        l = ProcessorItemLoader()
        assert l.selector is None

    def test_init_method_errors(self):
        l = ProcessorItemLoader()
        with pytest.raises(RuntimeError):
            l.add_xpath("url", "//a/@href")
        with pytest.raises(RuntimeError):
            l.replace_xpath("url", "//a/@href")
        with pytest.raises(RuntimeError):
            l.get_xpath("//a/@href")
        with pytest.raises(RuntimeError):
            l.add_css("name", "#name::text")
        with pytest.raises(RuntimeError):
            l.replace_css("name", "#name::text")
        with pytest.raises(RuntimeError):
            l.get_css("#name::text")

    def test_init_method_with_selector(self):
        sel = Selector(text="<html><body><div>marta</div></body></html>")
        l = ProcessorItemLoader(selector=sel)
        assert l.selector is sel

        l.add_xpath("name", "//div/text()")
        assert l.get_output_value("name") == ["Marta"]

    def test_init_method_with_selector_css(self):
        sel = Selector(text="<html><body><div>marta</div></body></html>")
        l = ProcessorItemLoader(selector=sel)
        assert l.selector is sel

        l.add_css("name", "div::text")
        assert l.get_output_value("name") == ["Marta"]

    def test_init_method_with_base_response(self):
        """Selector should be None after initialization"""
        response = Response("https://scrapy.org")
        l = ProcessorItemLoader(response=response)
        assert l.selector is None

    def test_init_method_with_response(self):
        l = ProcessorItemLoader(response=self.response)
        assert l.selector

        l.add_xpath("name", "//div/text()")
        assert l.get_output_value("name") == ["Marta"]

    def test_init_method_with_response_css(self):
        l = ProcessorItemLoader(response=self.response)
        assert l.selector

        l.add_css("name", "div::text")
        assert l.get_output_value("name") == ["Marta"]

        l.add_css("url", "a::attr(href)")
        assert l.get_output_value("url") == ["http://www.scrapy.org"]

        # combining/accumulating CSS selectors and XPath expressions
        l.add_xpath("name", "//div/text()")
        assert l.get_output_value("name") == ["Marta", "Marta"]

        l.add_xpath("url", "//img/@src")
        assert l.get_output_value("url") == [
            "http://www.scrapy.org",
            "/images/logo.png",
        ]

    def test_add_xpath_re(self):
        l = ProcessorItemLoader(response=self.response)
        l.add_xpath("name", "//div/text()", re="ma")
        assert l.get_output_value("name") == ["Ma"]

    def test_replace_xpath(self):
        l = ProcessorItemLoader(response=self.response)
        assert l.selector
        l.add_xpath("name", "//div/text()")
        assert l.get_output_value("name") == ["Marta"]
        l.replace_xpath("name", "//p/text()")
        assert l.get_output_value("name") == ["Paragraph"]

        l.replace_xpath("name", ["//p/text()", "//div/text()"])
        assert l.get_output_value("name") == ["Paragraph", "Marta"]

    def test_get_xpath(self):
        l = ProcessorItemLoader(response=self.response)
        assert l.get_xpath("//p/text()") == ["paragraph"]
        assert l.get_xpath("//p/text()", TakeFirst()) == "paragraph"
        assert l.get_xpath("//p/text()", TakeFirst(), re="pa") == "pa"

        assert l.get_xpath(["//p/text()", "//div/text()"]) == ["paragraph", "marta"]

    def test_replace_xpath_multi_fields(self):
        l = ProcessorItemLoader(response=self.response)
        l.add_xpath(None, "//div/text()", TakeFirst(), lambda x: {"name": x})
        assert l.get_output_value("name") == ["Marta"]
        l.replace_xpath(None, "//p/text()", TakeFirst(), lambda x: {"name": x})
        assert l.get_output_value("name") == ["Paragraph"]

    def test_replace_xpath_re(self):
        l = ProcessorItemLoader(response=self.response)
        assert l.selector
        l.add_xpath("name", "//div/text()")
        assert l.get_output_value("name") == ["Marta"]
        l.replace_xpath("name", "//div/text()", re="ma")
        assert l.get_output_value("name") == ["Ma"]

    def test_add_css_re(self):
        l = ProcessorItemLoader(response=self.response)
        l.add_css("name", "div::text", re="ma")
        assert l.get_output_value("name") == ["Ma"]

        l.add_css("url", "a::attr(href)", re="http://(.+)")
        assert l.get_output_value("url") == ["www.scrapy.org"]

    def test_replace_css(self):
        l = ProcessorItemLoader(response=self.response)
        assert l.selector
        l.add_css("name", "div::text")
        assert l.get_output_value("name") == ["Marta"]
        l.replace_css("name", "p::text")
        assert l.get_output_value("name") == ["Paragraph"]

        l.replace_css("name", ["p::text", "div::text"])
        assert l.get_output_value("name") == ["Paragraph", "Marta"]

        l.add_css("url", "a::attr(href)", re="http://(.+)")
        assert l.get_output_value("url") == ["www.scrapy.org"]
        l.replace_css("url", "img::attr(src)")
        assert l.get_output_value("url") == ["/images/logo.png"]

    def test_get_css(self):
        l = ProcessorItemLoader(response=self.response)
        assert l.get_css("p::text") == ["paragraph"]
        assert l.get_css("p::text", TakeFirst()) == "paragraph"
        assert l.get_css("p::text", TakeFirst(), re="pa") == "pa"

        assert l.get_css(["p::text", "div::text"]) == ["paragraph", "marta"]
        assert l.get_css(["a::attr(href)", "img::attr(src)"]) == [
            "http://www.scrapy.org",
            "/images/logo.png",
        ]

    def test_replace_css_multi_fields(self):
        l = ProcessorItemLoader(response=self.response)
        l.add_css(None, "div::text", TakeFirst(), lambda x: {"name": x})
        assert l.get_output_value("name") == ["Marta"]
        l.replace_css(None, "p::text", TakeFirst(), lambda x: {"name": x})
        assert l.get_output_value("name") == ["Paragraph"]

        l.add_css(None, "a::attr(href)", TakeFirst(), lambda x: {"url": x})
        assert l.get_output_value("url") == ["http://www.scrapy.org"]
        l.replace_css(None, "img::attr(src)", TakeFirst(), lambda x: {"url": x})
        assert l.get_output_value("url") == ["/images/logo.png"]

    def test_replace_css_re(self):
        l = ProcessorItemLoader(response=self.response)
        assert l.selector
        l.add_css("url", "a::attr(href)")
        assert l.get_output_value("url") == ["http://www.scrapy.org"]
        l.replace_css("url", "a::attr(href)", re=r"http://www\.(.+)")
        assert l.get_output_value("url") == ["scrapy.org"]


class TestSubselectorLoader:
    response = HtmlResponse(
        url="",
        encoding="utf-8",
        body=b"""
    <html>
    <body>
    <header>
      <div id="id">marta</div>
      <p>paragraph</p>
    </header>
    <footer class="footer">
      <a href="http://www.scrapy.org">homepage</a>
      <img src="/images/logo.png" width="244" height="65" alt="Scrapy">
    </footer>
    </body>
    </html>
    """,
    )

    def test_nested_xpath(self):
        l = NestedItemLoader(response=self.response)

        nl = l.nested_xpath("//header")
        nl.add_xpath("name", "div/text()")
        nl.add_css("name_div", "#id")
        nl.add_value("name_value", nl.selector.xpath('div[@id = "id"]/text()').getall())

        assert l.get_output_value("name") == ["marta"]
        assert l.get_output_value("name_div") == ['<div id="id">marta</div>']
        assert l.get_output_value("name_value") == ["marta"]

        assert l.get_output_value("name") == nl.get_output_value("name")
        assert l.get_output_value("name_div") == nl.get_output_value("name_div")
        assert l.get_output_value("name_value") == nl.get_output_value("name_value")

    def test_nested_css(self):
        l = NestedItemLoader(response=self.response)
        nl = l.nested_css("header")
        nl.add_xpath("name", "div/text()")
        nl.add_css("name_div", "#id")
        nl.add_value("name_value", nl.selector.xpath('div[@id = "id"]/text()').getall())

        assert l.get_output_value("name") == ["marta"]
        assert l.get_output_value("name_div") == ['<div id="id">marta</div>']
        assert l.get_output_value("name_value") == ["marta"]

        assert l.get_output_value("name") == nl.get_output_value("name")
        assert l.get_output_value("name_div") == nl.get_output_value("name_div")
        assert l.get_output_value("name_value") == nl.get_output_value("name_value")

    def test_nested_replace(self):
        l = NestedItemLoader(response=self.response)
        nl1 = l.nested_xpath("//footer")
        nl2 = nl1.nested_xpath("a")

        l.add_xpath("url", "//footer/a/@href")
        assert l.get_output_value("url") == ["http://www.scrapy.org"]
        nl1.replace_xpath("url", "img/@src")
        assert l.get_output_value("url") == ["/images/logo.png"]
        nl2.replace_xpath("url", "@href")
        assert l.get_output_value("url") == ["http://www.scrapy.org"]

    def test_nested_ordering(self):
        l = NestedItemLoader(response=self.response)
        nl1 = l.nested_xpath("//footer")
        nl2 = nl1.nested_xpath("a")

        nl1.add_xpath("url", "img/@src")
        l.add_xpath("url", "//footer/a/@href")
        nl2.add_xpath("url", "text()")
        l.add_xpath("url", "//footer/a/@href")

        assert l.get_output_value("url") == [
            "/images/logo.png",
            "http://www.scrapy.org",
            "homepage",
            "http://www.scrapy.org",
        ]

    def test_nested_load_item(self):
        l = NestedItemLoader(response=self.response)
        nl1 = l.nested_xpath("//footer")
        nl2 = nl1.nested_xpath("img")

        l.add_xpath("name", "//header/div/text()")
        nl1.add_xpath("url", "a/@href")
        nl2.add_xpath("image", "@src")

        item = l.load_item()

        assert item is l.item
        assert item is nl1.item
        assert item is nl2.item

        assert item["name"] == ["marta"]
        assert item["url"] == ["http://www.scrapy.org"]
        assert item["image"] == ["/images/logo.png"]


# Functions as processors


def function_processor_strip(iterable):
    return [x.strip() for x in iterable]


def function_processor_upper(iterable):
    return [x.upper() for x in iterable]


class FunctionProcessorItem(Item):
    foo = Field(
        input_processor=function_processor_strip,
        output_processor=function_processor_upper,
    )


class FunctionProcessorItemLoader(ItemLoader):
    default_item_class = FunctionProcessorItem


class TestFunctionProcessor:
    def test_processor_defined_in_item(self):
        lo = FunctionProcessorItemLoader()
        lo.add_value("foo", "  bar  ")
        lo.add_value("foo", ["  asdf  ", "  qwerty  "])
        assert dict(lo.load_item()) == {"foo": ["BAR", "ASDF", "QWERTY"]}