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Support for dataclass and attrs items (#3881)

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Eugenio Lacuesta 2020-06-14 06:45:27 -03:00 committed by GitHub
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36 changed files with 753 additions and 351 deletions
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1
docs/conf.py
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@ -281,6 +281,7 @@ coverage_ignore_pyobjects = [
# -------------------------------------
intersphinx_mapping = {
'attrs': ('https://www.attrs.org/en/stable/', None),
'coverage': ('https://coverage.readthedocs.io/en/stable', None),
'cssselect': ('https://cssselect.readthedocs.io/en/latest', None),
'pytest': ('https://docs.pytest.org/en/latest', None),

8
docs/faq.rst
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@ -342,15 +342,15 @@ method for this purpose. For example::
from copy import deepcopy
from scrapy.item import Item
from itemadapter import is_item, ItemAdapter
class MultiplyItemsMiddleware:
def process_spider_output(self, response, result, spider):
for item in result:
if isinstance(item, (Item, dict)):
for _ in range(item['multiply_by']):
if is_item(item):
adapter = ItemAdapter(item)
for _ in range(adapter['multiply_by']):
yield deepcopy(item)
Does Scrapy support IPv6 addresses?

2
docs/topics/architecture.rst
View File

@ -104,7 +104,7 @@ Spiders
-------
Spiders are custom classes written by Scrapy users to parse responses and
extract items (aka scraped items) from them or additional requests to
extract :ref:`items <topics-items>` from them or additional requests to
follow. For more information see :ref:`topics-spiders`.
.. _component-pipelines:

13
docs/topics/coroutines.rst
View File

@ -53,21 +53,28 @@ There are several use cases for coroutines in Scrapy. Code that would
return Deferreds when written for previous Scrapy versions, such as downloader
middlewares and signal handlers, can be rewritten to be shorter and cleaner::
from itemadapter import ItemAdapter
class DbPipeline:
def _update_item(self, data, item):
item['field'] = data
adapter = ItemAdapter(item)
adapter['field'] = data
return item
def process_item(self, item, spider):
dfd = db.get_some_data(item['id'])
adapter = ItemAdapter(item)
dfd = db.get_some_data(adapter['id'])
dfd.addCallback(self._update_item, item)
return dfd
becomes::
from itemadapter import ItemAdapter
class DbPipeline:
async def process_item(self, item, spider):
item['field'] = await db.get_some_data(item['id'])
adapter = ItemAdapter(item)
adapter['field'] = await db.get_some_data(adapter['id'])
return item
Coroutines may be used to call asynchronous code. This includes other

34
docs/topics/exporters.rst
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@ -40,6 +40,7 @@ Here you can see an :doc:`Item Pipeline <item-pipeline>` which uses multiple
Item Exporters to group scraped items to different files according to the
value of one of their fields::
from itemadapter import ItemAdapter
from scrapy.exporters import XmlItemExporter
class PerYearXmlExportPipeline:
@ -53,7 +54,8 @@ value of one of their fields::
exporter.finish_exporting()
def _exporter_for_item(self, item):
year = item['year']
adapter = ItemAdapter(item)
year = adapter['year']
if year not in self.year_to_exporter:
f = open('{}.xml'.format(year), 'wb')
exporter = XmlItemExporter(f)
@ -167,9 +169,10 @@ BaseItemExporter
value unchanged except for ``unicode`` values which are encoded to
``str`` using the encoding declared in the :attr:`encoding` attribute.
:param field: the field being serialized. If a raw dict is being
exported (not :class:`~.Item`) *field* value is an empty dict.
:type field: :class:`~scrapy.item.Field` object or an empty dict
:param field: the field being serialized. If the source :ref:`item object
<item-types>` does not define field metadata, *field* is an empty
:class:`dict`.
:type field: :class:`~scrapy.item.Field` object or a :class:`dict` instance
:param name: the name of the field being serialized
:type name: str
@ -192,14 +195,17 @@ BaseItemExporter
.. attribute:: fields_to_export
A list with the name of the fields that will be exported, or None if you
want to export all fields. Defaults to None.
A list with the name of the fields that will be exported, or ``None`` if
you want to export all fields. Defaults to ``None``.
Some exporters (like :class:`CsvItemExporter`) respect the order of the
fields defined in this attribute.
Some exporters may require fields_to_export list in order to export the
data properly when spiders return dicts (not :class:`~Item` instances).
When using :ref:`item objects <item-types>` that do not expose all their
possible fields, exporters that do not support exporting a different
subset of fields per item will only export the fields found in the first
item exported. Use ``fields_to_export`` to define all the fields to be
exported.
.. attribute:: export_empty_fields
@ -238,7 +244,7 @@ XmlItemExporter
.. class:: XmlItemExporter(file, item_element='item', root_element='items', **kwargs)
Exports Items in XML format to the specified file object.
Exports items in XML format to the specified file object.
:param file: the file-like object to use for exporting the data. Its ``write`` method should
accept ``bytes`` (a disk file opened in binary mode, a ``io.BytesIO`` object, etc)
@ -292,7 +298,7 @@ CsvItemExporter
.. class:: CsvItemExporter(file, include_headers_line=True, join_multivalued=',', **kwargs)
Exports Items in CSV format to the given file-like object. If the
Exports items in CSV format to the given file-like object. If the
:attr:`fields_to_export` attribute is set, it will be used to define the
CSV columns and their order. The :attr:`export_empty_fields` attribute has
no effect on this exporter.
@ -325,7 +331,7 @@ PickleItemExporter
.. class:: PickleItemExporter(file, protocol=0, **kwargs)
Exports Items in pickle format to the given file-like object.
Exports items in pickle format to the given file-like object.
:param file: the file-like object to use for exporting the data. Its ``write`` method should
accept ``bytes`` (a disk file opened in binary mode, a ``io.BytesIO`` object, etc)
@ -345,7 +351,7 @@ PprintItemExporter
.. class:: PprintItemExporter(file, **kwargs)
Exports Items in pretty print format to the specified file object.
Exports items in pretty print format to the specified file object.
:param file: the file-like object to use for exporting the data. Its ``write`` method should
accept ``bytes`` (a disk file opened in binary mode, a ``io.BytesIO`` object, etc)
@ -365,7 +371,7 @@ JsonItemExporter
.. class:: JsonItemExporter(file, **kwargs)
Exports Items in JSON format to the specified file-like object, writing all
Exports items in JSON format to the specified file-like object, writing all
objects as a list of objects. The additional ``__init__`` method arguments are
passed to the :class:`BaseItemExporter` ``__init__`` method, and the leftover
arguments to the :class:`~json.JSONEncoder` ``__init__`` method, so you can use any
@ -394,7 +400,7 @@ JsonLinesItemExporter
.. class:: JsonLinesItemExporter(file, **kwargs)
Exports Items in JSON format to the specified file-like object, writing one
Exports items in JSON format to the specified file-like object, writing one
JSON-encoded item per line. The additional ``__init__`` method arguments are passed
to the :class:`BaseItemExporter` ``__init__`` method, and the leftover arguments to
the :class:`~json.JSONEncoder` ``__init__`` method, so you can use any

4
docs/topics/feed-exports.rst
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@ -298,8 +298,8 @@ Example: ``FEED_EXPORT_FIELDS = ["foo", "bar", "baz"]``.
Use FEED_EXPORT_FIELDS option to define fields to export and their order.
When FEED_EXPORT_FIELDS is empty or None (default), Scrapy uses fields
defined in dicts or :class:`~.Item` subclasses a spider is yielding.
When FEED_EXPORT_FIELDS is empty or None (default), Scrapy uses the fields
defined in :ref:`item objects <topics-items>` yielded by your spider.
If an exporter requires a fixed set of fields (this is the case for
:ref:`CSV <topics-feed-format-csv>` export format) and FEED_EXPORT_FIELDS

54
docs/topics/item-pipeline.rst
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@ -27,15 +27,19 @@ Each item pipeline component is a Python class that must implement the following
.. method:: process_item(self, item, spider)
This method is called for every item pipeline component. :meth:`process_item`
must either: return a dict with data, return an :class:`~scrapy.item.Item`
(or any descendant class) object, return a
:class:`~twisted.internet.defer.Deferred` or raise
:exc:`~scrapy.exceptions.DropItem` exception. Dropped items are no longer
processed by further pipeline components.
This method is called for every item pipeline component.
:param item: the item scraped
:type item: :class:`~scrapy.item.Item` object or a dict
`item` is an :ref:`item object <item-types>`, see
:ref:`supporting-item-types`.
:meth:`process_item` must either: return an :ref:`item object <item-types>`,
return a :class:`~twisted.internet.defer.Deferred` or raise a
:exc:`~scrapy.exceptions.DropItem` exception.
Dropped items are no longer processed by further pipeline components.
:param item: the scraped item
:type item: :ref:`item object <item-types>`
:param spider: the spider which scraped the item
:type spider: :class:`~scrapy.spiders.Spider` object
@ -79,16 +83,17 @@ Let's take a look at the following hypothetical pipeline that adjusts the
(``price_excludes_vat`` attribute), and drops those items which don't
contain a price::
from itemadapter import ItemAdapter
from scrapy.exceptions import DropItem
class PricePipeline:
vat_factor = 1.15
def process_item(self, item, spider):
if item.get('price'):
if item.get('price_excludes_vat'):
item['price'] = item['price'] * self.vat_factor
adapter = ItemAdapter(item)
if adapter.get('price'):
if adapter.get('price_excludes_vat'):
adapter['price'] = adapter['price'] * self.vat_factor
return item
else:
raise DropItem("Missing price in %s" % item)
@ -103,6 +108,8 @@ format::
import json
from itemadapter import ItemAdapter
class JsonWriterPipeline:
def open_spider(self, spider):
@ -112,7 +119,7 @@ format::
self.file.close()
def process_item(self, item, spider):
line = json.dumps(dict(item)) + "\n"
line = json.dumps(ItemAdapter(item).asdict()) + "\n"
self.file.write(line)
return item
@ -131,6 +138,7 @@ The main point of this example is to show how to use :meth:`from_crawler`
method and how to clean up the resources properly.::
import pymongo
from itemadapter import ItemAdapter
class MongoPipeline:
@ -155,7 +163,7 @@ method and how to clean up the resources properly.::
self.client.close()
def process_item(self, item, spider):
self.db[self.collection_name].insert_one(dict(item))
self.db[self.collection_name].insert_one(ItemAdapter(item).asdict())
return item
.. _MongoDB: https://www.mongodb.com/
@ -177,10 +185,11 @@ item.
::
import scrapy
import hashlib
from urllib.parse import quote
import scrapy
from itemadapter import ItemAdapter
class ScreenshotPipeline:
"""Pipeline that uses Splash to render screenshot of
@ -189,7 +198,8 @@ item.
SPLASH_URL = "http://localhost:8050/render.png?url={}"
async def process_item(self, item, spider):
encoded_item_url = quote(item["url"])
adapter = ItemAdapter(item)
encoded_item_url = quote(adapter["url"])
screenshot_url = self.SPLASH_URL.format(encoded_item_url)
request = scrapy.Request(screenshot_url)
response = await spider.crawler.engine.download(request, spider)
@ -199,14 +209,14 @@ item.
return item
# Save screenshot to file, filename will be hash of url.
url = item["url"]
url = adapter["url"]
url_hash = hashlib.md5(url.encode("utf8")).hexdigest()
filename = "{}.png".format(url_hash)
with open(filename, "wb") as f:
f.write(response.body)
# Store filename in item.
item["screenshot_filename"] = filename
adapter["screenshot_filename"] = filename
return item
.. _Splash: https://splash.readthedocs.io/en/stable/
@ -219,6 +229,7 @@ already processed. Let's say that our items have a unique id, but our spider
returns multiples items with the same id::
from itemadapter import ItemAdapter
from scrapy.exceptions import DropItem
class DuplicatesPipeline:
@ -227,10 +238,11 @@ returns multiples items with the same id::
self.ids_seen = set()
def process_item(self, item, spider):
if item['id'] in self.ids_seen:
raise DropItem("Duplicate item found: %s" % item)
adapter = ItemAdapter(item)
if adapter['id'] in self.ids_seen:
raise DropItem("Duplicate item found: %r" % item)
else:
self.ids_seen.add(item['id'])
self.ids_seen.add(adapter['id'])
return item

241
docs/topics/items.rst
View File

@ -8,29 +8,155 @@ Items
:synopsis: Item and Field classes
The main goal in scraping is to extract structured data from unstructured
sources, typically, web pages. Scrapy spiders can return the extracted data
as Python dicts. While convenient and familiar, Python dicts lack structure:
it is easy to make a typo in a field name or return inconsistent data,
especially in a larger project with many spiders.
sources, typically, web pages. :ref:`Spiders <topics-spiders>` may return the
extracted data as `items`, Python objects that define key-value pairs.
To define common output data format Scrapy provides the :class:`Item` class.
:class:`Item` objects are simple containers used to collect the scraped data.
They provide an API similar to :class:`dict` API with a convenient syntax
for declaring their available fields.
Scrapy supports :ref:`multiple types of items <item-types>`. When you create an
item, you may use whichever type of item you want. When you write code that
receives an item, your code should :ref:`work for any item type
<supporting-item-types>`.
Various Scrapy components use extra information provided by Items:
exporters look at declared fields to figure out columns to export,
serialization can be customized using Item fields metadata, :mod:`trackref`
tracks Item instances to help find memory leaks
(see :ref:`topics-leaks-trackrefs`), etc.
.. _item-types:
Item Types
==========
Scrapy supports the following types of items, via the `itemadapter`_ library:
:ref:`dictionaries <dict-items>`, :ref:`Item objects <item-objects>`,
:ref:`dataclass objects <dataclass-items>`, and :ref:`attrs objects <attrs-items>`.
.. _itemadapter: https://github.com/scrapy/itemadapter
.. _dict-items:
Dictionaries
------------
As an item type, :class:`dict` is convenient and familiar.
.. _item-objects:
Item objects
------------
:class:`Item` provides a :class:`dict`-like API plus additional features that
make it the most feature-complete item type:
.. class:: Item([arg])
:class:`Item` objects replicate the standard :class:`dict` API, including
its ``__init__`` method.
:class:`Item` allows defining field names, so that:
- :class:`KeyError` is raised when using undefined field names (i.e.
prevents typos going unnoticed)
- :ref:`Item exporters <topics-exporters>` can export all fields by
default even if the first scraped object does not have values for all
of them
:class:`Item` also allows defining field metadata, which can be used to
:ref:`customize serialization <topics-exporters-field-serialization>`.
:mod:`trackref` tracks :class:`Item` objects to help find memory leaks
(see :ref:`topics-leaks-trackrefs`).
:class:`Item` objects also provide the following additional API members:
.. automethod:: copy
.. automethod:: deepcopy
.. attribute:: fields
A dictionary containing *all declared fields* for this Item, not only
those populated. The keys are the field names and the values are the
:class:`Field` objects used in the :ref:`Item declaration
<topics-items-declaring>`.
Example::
from scrapy.item import Item, Field
class CustomItem(Item):
one_field = Field()
another_field = Field()
.. _dataclass-items:
Dataclass objects
-----------------
.. versionadded:: 2.2
:func:`~dataclasses.dataclass` allows defining item classes with field names,
so that :ref:`item exporters <topics-exporters>` can export all fields by
default even if the first scraped object does not have values for all of them.
Additionally, ``dataclass`` items also allow to:
* define the type and default value of each defined field.
* define custom field metadata through :func:`dataclasses.field`, which can be used to
:ref:`customize serialization <topics-exporters-field-serialization>`.
They work natively in Python 3.7 or later, or using the `dataclasses
backport`_ in Python 3.6.
.. _dataclasses backport: https://pypi.org/project/dataclasses/
Example::
from dataclasses import dataclass
@dataclass
class CustomItem:
one_field: str
another_field: int
.. note:: Field types are not enforced at run time.
.. _attrs-items:
attr.s objects
--------------
.. versionadded:: 2.2
:func:`attr.s` allows defining item classes with field names,
so that :ref:`item exporters <topics-exporters>` can export all fields by
default even if the first scraped object does not have values for all of them.
Additionally, ``attr.s`` items also allow to:
* define the type and default value of each defined field.
* define custom field :ref:`metadata <attrs:metadata>`, which can be used to
:ref:`customize serialization <topics-exporters-field-serialization>`.
In order to use this type, the :doc:`attrs package <attrs:index>` needs to be installed.
Example::
import attr
@attr.s
class CustomItem:
one_field = attr.ib()
another_field = attr.ib()
Working with Item objects
=========================
.. _topics-items-declaring:
Declaring Items
===============
Declaring Item subclasses
-------------------------
Items are declared using a simple class definition syntax and :class:`Field`
objects. Here is an example::
Item subclasses are declared using a simple class definition syntax and
:class:`Field` objects. Here is an example::
import scrapy
@ -48,10 +174,11 @@ objects. Here is an example::
.. _Django: https://www.djangoproject.com/
.. _Django Models: https://docs.djangoproject.com/en/dev/topics/db/models/
.. _topics-items-fields:
Item Fields
===========
Declaring fields
----------------
:class:`Field` objects are used to specify metadata for each field. For
example, the serializer function for the ``last_updated`` field illustrated in
@ -72,15 +199,31 @@ It's important to note that the :class:`Field` objects used to declare the item
do not stay assigned as class attributes. Instead, they can be accessed through
the :attr:`Item.fields` attribute.
Working with Items
==================
.. class:: Field([arg])
The :class:`Field` class is just an alias to the built-in :class:`dict` class and
doesn't provide any extra functionality or attributes. In other words,
:class:`Field` objects are plain-old Python dicts. A separate class is used
to support the :ref:`item declaration syntax <topics-items-declaring>`
based on class attributes.
.. note:: Field metadata can also be declared for ``dataclass`` and ``attrs``
items. Please refer to the documentation for `dataclasses.field`_ and
`attr.ib`_ for additional information.
.. _dataclasses.field: https://docs.python.org/3/library/dataclasses.html#dataclasses.field
.. _attr.ib: https://www.attrs.org/en/stable/api.html#attr.ib
Working with Item objects
-------------------------
Here are some examples of common tasks performed with items, using the
``Product`` item :ref:`declared above <topics-items-declaring>`. You will
notice the API is very similar to the :class:`dict` API.
Creating items
--------------
''''''''''''''
>>> product = Product(name='Desktop PC', price=1000)
>>> print(product)
@ -88,7 +231,7 @@ Product(name='Desktop PC', price=1000)
Getting field values
--------------------
''''''''''''''''''''
>>> product['name']
Desktop PC
@ -128,7 +271,7 @@ False
Setting field values
--------------------
''''''''''''''''''''
>>> product['last_updated'] = 'today'
>>> product['last_updated']
@ -141,7 +284,7 @@ KeyError: 'Product does not support field: lala'
Accessing all populated values
------------------------------
''''''''''''''''''''''''''''''
To access all populated values, just use the typical :class:`dict` API:
@ -155,7 +298,7 @@ To access all populated values, just use the typical :class:`dict` API:
.. _copying-items:
Copying items
-------------
'''''''''''''
To copy an item, you must first decide whether you want a shallow copy or a
deep copy.
@ -183,7 +326,7 @@ To create a deep copy, call :meth:`~scrapy.item.Item.deepcopy` instead
Other common tasks
------------------
''''''''''''''''''
Creating dicts from items:
@ -201,8 +344,8 @@ Traceback (most recent call last):
KeyError: 'Product does not support field: lala'
Extending Items
===============
Extending Item subclasses
-------------------------
You can extend Items (to add more fields or to change some metadata for some
fields) by declaring a subclass of your original Item.
@ -222,39 +365,25 @@ appending more values, or changing existing values, like this::
That adds (or replaces) the ``serializer`` metadata key for the ``name`` field,
keeping all the previously existing metadata values.
Item objects
============
.. class:: Item([arg])
.. _supporting-item-types:
Return a new Item optionally initialized from the given argument.
Supporting All Item Types
=========================
Items replicate the standard :class:`dict` API, including its ``__init__``
method, and also provide the following additional API members:
In code that receives an item, such as methods of :ref:`item pipelines
<topics-item-pipeline>` or :ref:`spider middlewares
<topics-spider-middleware>`, it is a good practice to use the
:class:`~itemadapter.ItemAdapter` class and the
:func:`~itemadapter.is_item` function to write code that works for
any :ref:`supported item type <item-types>`:
.. automethod:: copy
.. autoclass:: itemadapter.ItemAdapter
.. automethod:: deepcopy
.. autofunction:: itemadapter.is_item
.. attribute:: fields
A dictionary containing *all declared fields* for this Item, not only
those populated. The keys are the field names and the values are the
:class:`Field` objects used in the :ref:`Item declaration
<topics-items-declaring>`.
Field objects
=============
.. class:: Field([arg])
The :class:`Field` class is just an alias to the built-in :class:`dict` class and
doesn't provide any extra functionality or attributes. In other words,
:class:`Field` objects are plain-old Python dicts. A separate class is used
to support the :ref:`item declaration syntax <topics-items-declaring>`
based on class attributes.
Other classes related to Item
=============================
Other classes related to items
==============================
.. autoclass:: ItemMeta

15
docs/topics/leaks.rst
View File

@ -4,7 +4,7 @@
Debugging memory leaks
======================
In Scrapy, objects such as Requests, Responses and Items have a finite
In Scrapy, objects such as requests, responses and items have a finite
lifetime: they are created, used for a while, and finally destroyed.
From all those objects, the Request is probably the one with the longest
@ -61,8 +61,8 @@ Debugging memory leaks with ``trackref``
========================================
:mod:`trackref` is a module provided by Scrapy to debug the most common cases of
memory leaks. It basically tracks the references to all live Requests,
Responses, Item and Selector objects.
memory leaks. It basically tracks the references to all live Request,
Response, Item, Spider and Selector objects.
You can enter the telnet console and inspect how many objects (of the classes
mentioned above) are currently alive using the ``prefs()`` function which is an
@ -200,11 +200,10 @@ Debugging memory leaks with muppy
``trackref`` provides a very convenient mechanism for tracking down memory
leaks, but it only keeps track of the objects that are more likely to cause
memory leaks (Requests, Responses, Items, and Selectors). However, there are
other cases where the memory leaks could come from other (more or less obscure)
objects. If this is your case, and you can't find your leaks using ``trackref``,
you still have another resource: the muppy library.
memory leaks. However, there are other cases where the memory leaks could come
from other (more or less obscure) objects. If this is your case, and you can't
find your leaks using ``trackref``, you still have another resource: the muppy
library.
You can use muppy from `Pympler`_.

53
docs/topics/loaders.rst
View File

@ -7,13 +7,12 @@ Item Loaders
.. module:: scrapy.loader
:synopsis: Item Loader class
Item Loaders provide a convenient mechanism for populating scraped :ref:`Items
<topics-items>`. Even though Items can be populated using their own
dictionary-like API, Item Loaders provide a much more convenient API for
populating them from a scraping process, by automating some common tasks like
parsing the raw extracted data before assigning it.
Item Loaders provide a convenient mechanism for populating scraped :ref:`items
<topics-items>`. Even though items can be populated directly, Item Loaders provide a
much more convenient API for populating them from a scraping process, by automating
some common tasks like parsing the raw extracted data before assigning it.
In other words, :ref:`Items <topics-items>` provide the *container* of
In other words, :ref:`items <topics-items>` provide the *container* of
scraped data, while Item Loaders provide the mechanism for *populating* that
container.
@ -25,10 +24,10 @@ Using Item Loaders to populate items
====================================
To use an Item Loader, you must first instantiate it. You can either
instantiate it with a dict-like object (e.g. Item or dict) or without one, in
which case an Item is automatically instantiated in the Item Loader ``__init__`` method
using the Item class specified in the :attr:`ItemLoader.default_item_class`
attribute.
instantiate it with an :ref:`item object <topics-items>` or without one, in which
case an instance of :class:`~scrapy.item.Item` is automatically created in the
Item Loader ``__init__`` method using the :class:`~scrapy.item.Item` subclass
specified in the :attr:`ItemLoader.default_item_class` attribute.
Then, you start collecting values into the Item Loader, typically using
:ref:`Selectors <topics-selectors>`. You can add more than one value to
@ -88,7 +87,7 @@ received (through the :meth:`~ItemLoader.add_xpath`, :meth:`~ItemLoader.add_css`
:meth:`~ItemLoader.add_value` methods) and the result of the input processor is
collected and kept inside the ItemLoader. After collecting all data, the
:meth:`ItemLoader.load_item` method is called to populate and get the populated
:class:`~scrapy.item.Item` object. That's when the output processor is
:ref:`item object <topics-items>`. That's when the output processor is
called with the data previously collected (and processed using the input
processor). The result of the output processor is the final value that gets
assigned to the item.
@ -153,12 +152,10 @@ Last, but not least, Scrapy comes with some :ref:`commonly used processors
<topics-loaders-available-processors>` built-in for convenience.
Declaring Item Loaders
======================
Item Loaders are declared like Items, by using a class definition syntax. Here
is an example::
Item Loaders are declared using a class definition syntax. Here is an example::
from scrapy.loader import ItemLoader
from scrapy.loader.processors import TakeFirst, MapCompose, Join
@ -275,9 +272,9 @@ ItemLoader objects
.. class:: ItemLoader([item, selector, response], **kwargs)
Return a new Item Loader for populating the given Item. If no item is
given, one is instantiated automatically using the class in
:attr:`default_item_class`.
Return a new Item Loader for populating the given :ref:`item object
<topics-items>`. If no item object is given, one is instantiated
automatically using the class in :attr:`default_item_class`.
When instantiated with a ``selector`` or a ``response`` parameters
the :class:`ItemLoader` class provides convenient mechanisms for extracting
@ -286,7 +283,7 @@ ItemLoader objects
:param item: The item instance to populate using subsequent calls to
:meth:`~ItemLoader.add_xpath`, :meth:`~ItemLoader.add_css`,
or :meth:`~ItemLoader.add_value`.
:type item: :class:`~scrapy.item.Item` object
:type item: :ref:`item object <topics-items>`
:param selector: The selector to extract data from, when using the
:meth:`add_xpath` (resp. :meth:`add_css`) or :meth:`replace_xpath`
@ -444,17 +441,19 @@ ItemLoader objects
Create a nested loader with an xpath selector.
The supplied selector is applied relative to selector associated
with this :class:`ItemLoader`. The nested loader shares the :class:`Item`
with the parent :class:`ItemLoader` so calls to :meth:`add_xpath`,
:meth:`add_value`, :meth:`replace_value`, etc. will behave as expected.
with this :class:`ItemLoader`. The nested loader shares the :ref:`item
object <topics-items>` with the parent :class:`ItemLoader` so calls to
:meth:`add_xpath`, :meth:`add_value`, :meth:`replace_value`, etc. will
behave as expected.
.. method:: nested_css(css)
Create a nested loader with a css selector.
The supplied selector is applied relative to selector associated
with this :class:`ItemLoader`. The nested loader shares the :class:`Item`
with the parent :class:`ItemLoader` so calls to :meth:`add_xpath`,
:meth:`add_value`, :meth:`replace_value`, etc. will behave as expected.
with this :class:`ItemLoader`. The nested loader shares the :ref:`item
object <topics-items>` with the parent :class:`ItemLoader` so calls to
:meth:`add_xpath`, :meth:`add_value`, :meth:`replace_value`, etc. will
behave as expected.
.. method:: get_collected_values(field_name)
@ -477,7 +476,7 @@ ItemLoader objects
.. attribute:: item
The :class:`~scrapy.item.Item` object being parsed by this Item Loader.
The :ref:`item object <topics-items>` being parsed by this Item Loader.
This is mostly used as a property so when attempting to override this
value, you may want to check out :attr:`default_item_class` first.
@ -488,8 +487,8 @@ ItemLoader objects
.. attribute:: default_item_class
An Item class (or factory), used to instantiate items when not given in
the ``__init__`` method.
An :ref:`item object <topics-items>` class or factory, used to
instantiate items when not given in the ``__init__`` method.
.. attribute:: default_input_processor

33
docs/topics/media-pipeline.rst
View File

@ -156,7 +156,7 @@ following forms::
ftp://username:password@address:port/path
ftp://address:port/path
If ``username`` and ``password`` are not provided, they are taken from the :setting:`FTP_USER` and
:setting:`FTP_PASSWORD` settings respectively.
@ -243,20 +243,22 @@ Usage example
.. setting:: IMAGES_URLS_FIELD
.. setting:: IMAGES_RESULT_FIELD
In order to use a media pipeline first, :ref:`enable it
In order to use a media pipeline, first :ref:`enable it
<topics-media-pipeline-enabling>`.
Then, if a spider returns a dict with the URLs key (``file_urls`` or
``image_urls``, for the Files or Images Pipeline respectively), the pipeline will
put the results under respective key (``files`` or ``images``).
Then, if a spider returns an :ref:`item object <topics-items>` with the URLs
field (``file_urls`` or ``image_urls``, for the Files or Images Pipeline
respectively), the pipeline will put the results under the respective field
(``files`` or ``images``).
If you prefer to use :class:`~.Item`, then define a custom item with the
necessary fields, like in this example for Images Pipeline::
When using :ref:`item types <item-types>` for which fields are defined beforehand,
you must define both the URLs field and the results field. For example, when
using the images pipeline, items must define both the ``image_urls`` and the
``images`` field. For instance, using the :class:`~scrapy.item.Item` class::
import scrapy
class MyItem(scrapy.Item):
# ... other item fields ...
image_urls = scrapy.Field()
images = scrapy.Field()
@ -445,8 +447,11 @@ See here the methods that you can override in your custom Files Pipeline:
:meth:`~get_media_requests` method and return a Request for each
file URL::
from itemadapter import ItemAdapter
def get_media_requests(self, item, info):
for file_url in item['file_urls']:
adapter = ItemAdapter(item)
for file_url in adapter['file_urls']:
yield scrapy.Request(file_url)
Those requests will be processed by the pipeline and, when they have finished
@ -509,13 +514,15 @@ See here the methods that you can override in your custom Files Pipeline:
store the downloaded file paths (passed in results) in the ``file_paths``
item field, and we drop the item if it doesn't contain any files::
from itemadapter import ItemAdapter
from scrapy.exceptions import DropItem
def item_completed(self, results, item, info):
file_paths = [x['path'] for ok, x in results if ok]
if not file_paths:
raise DropItem("Item contains no files")
item['file_paths'] = file_paths
adapter = ItemAdapter(item)
adapter['file_paths'] = file_paths
return item
By default, the :meth:`item_completed` method returns the item.
@ -589,8 +596,9 @@ Here is a full example of the Images Pipeline whose methods are exemplified
above::
import scrapy
from scrapy.pipelines.images import ImagesPipeline
from itemadapter import ItemAdapter
from scrapy.exceptions import DropItem
from scrapy.pipelines.images import ImagesPipeline
class MyImagesPipeline(ImagesPipeline):
@ -602,7 +610,8 @@ above::
image_paths = [x['path'] for ok, x in results if ok]
if not image_paths:
raise DropItem("Item contains no images")
item['image_paths'] = image_paths
adapter = ItemAdapter(item)
adapter['image_paths'] = image_paths
return item

4
docs/topics/settings.rst
View File

@ -236,8 +236,8 @@ CONCURRENT_ITEMS
Default: ``100``
Maximum number of concurrent items (per response) to process in parallel in the
Item Processor (also known as the :ref:`Item Pipeline <topics-item-pipeline>`).
Maximum number of concurrent items (per response) to process in parallel in
:ref:`item pipelines <topics-item-pipeline>`.
.. setting:: CONCURRENT_REQUESTS

10
docs/topics/signals.rst
View File

@ -151,8 +151,8 @@ item_scraped
This signal supports returning deferreds from its handlers.
:param item: the item scraped
:type item: dict or :class:`~scrapy.item.Item` object
:param item: the scraped item
:type item: :ref:`item object <item-types>`
:param spider: the spider which scraped the item
:type spider: :class:`~scrapy.spiders.Spider` object
@ -172,7 +172,7 @@ item_dropped
This signal supports returning deferreds from its handlers.
:param item: the item dropped from the :ref:`topics-item-pipeline`
:type item: dict or :class:`~scrapy.item.Item` object
:type item: :ref:`item object <item-types>`
:param spider: the spider which scraped the item
:type spider: :class:`~scrapy.spiders.Spider` object
@ -196,8 +196,8 @@ item_error
This signal supports returning deferreds from its handlers.
:param item: the item dropped from the :ref:`topics-item-pipeline`
:type item: dict or :class:`~scrapy.item.Item` object
:param item: the item that caused the error in the :ref:`topics-item-pipeline`
:type item: :ref:`item object <item-types>`
:param response: the response being processed when the exception was raised
:type response: :class:`~scrapy.http.Response` object

13
docs/topics/spider-middleware.rst
View File

@ -102,29 +102,28 @@ object gives you access, for example, to the :ref:`settings <topics-settings>`.
it has processed the response.
:meth:`process_spider_output` must return an iterable of
:class:`~scrapy.http.Request`, dict or :class:`~scrapy.item.Item`
objects.
:class:`~scrapy.http.Request` objects and :ref:`item object
<topics-items>`.
:param response: the response which generated this output from the
spider
:type response: :class:`~scrapy.http.Response` object
:param result: the result returned by the spider
:type result: an iterable of :class:`~scrapy.http.Request`, dict
or :class:`~scrapy.item.Item` objects
:type result: an iterable of :class:`~scrapy.http.Request` objects and
:ref:`item object <topics-items>`
:param spider: the spider whose result is being processed
:type spider: :class:`~scrapy.spiders.Spider` object
.. method:: process_spider_exception(response, exception, spider)
This method is called when a spider or :meth:`process_spider_output`
method (from a previous spider middleware) raises an exception.
:meth:`process_spider_exception` should return either ``None`` or an
iterable of :class:`~scrapy.http.Request`, dict or
:class:`~scrapy.item.Item` objects.
iterable of :class:`~scrapy.http.Request` objects and :ref:`item object
<topics-items>`.
If it returns ``None``, Scrapy will continue processing this exception,
executing any other :meth:`process_spider_exception` in the following

18
docs/topics/spiders.rst
View File

@ -23,8 +23,8 @@ For spiders, the scraping cycle goes through something like this:
:attr:`~scrapy.spiders.Spider.parse` method as callback function for the
Requests.
2. In the callback function, you parse the response (web page) and return either
dicts with extracted data, :class:`~scrapy.item.Item` objects,
2. In the callback function, you parse the response (web page) and return
:ref:`item objects <topics-items>`,
:class:`~scrapy.http.Request` objects, or an iterable of these objects.
Those Requests will also contain a callback (maybe
the same) and will then be downloaded by Scrapy and then their
@ -179,8 +179,8 @@ scrapy.Spider
the same requirements as the :class:`Spider` class.
This method, as well as any other Request callback, must return an
iterable of :class:`~scrapy.http.Request` and/or
dicts or :class:`~scrapy.item.Item` objects.
iterable of :class:`~scrapy.http.Request` and/or :ref:`item objects
<topics-items>`.
:param response: the response to parse
:type response: :class:`~scrapy.http.Response`
@ -234,7 +234,7 @@ Return multiple Requests and items from a single callback::
yield scrapy.Request(response.urljoin(href), self.parse)
Instead of :attr:`~.start_urls` you can use :meth:`~.start_requests` directly;
to give data more structure you can use :ref:`topics-items`::
to give data more structure you can use :class:`~scrapy.item.Item` objects::
import scrapy
from myproject.items import MyItem
@ -364,7 +364,7 @@ CrawlSpider
This method is called for the start_urls responses. It allows to parse
the initial responses and must return either an
:class:`~scrapy.item.Item` object, a :class:`~scrapy.http.Request`
:ref:`item object <topics-items>`, a :class:`~scrapy.http.Request`
object, or an iterable containing any of them.
Crawling rules
@ -383,7 +383,7 @@ Crawling rules
object with that name will be used) to be called for each link extracted with
the specified link extractor. This callback receives a :class:`~scrapy.http.Response`
as its first argument and must return either a single instance or an iterable of
:class:`~scrapy.item.Item`, ``dict`` and/or :class:`~scrapy.http.Request` objects
:ref:`item objects <topics-items>` and/or :class:`~scrapy.http.Request` objects
(or any subclass of them). As mentioned above, the received :class:`~scrapy.http.Response`
object will contain the text of the link that produced the :class:`~scrapy.http.Request`
in its ``meta`` dictionary (under the ``link_text`` key)
@ -531,7 +531,7 @@ XMLFeedSpider
(``itertag``). Receives the response and an
:class:`~scrapy.selector.Selector` for each node. Overriding this
method is mandatory. Otherwise, you spider won't work. This method
must return either a :class:`~scrapy.item.Item` object, a
must return an :ref:`item object <topics-items>`, a
:class:`~scrapy.http.Request` object, or an iterable containing any of
them.
@ -541,7 +541,7 @@ XMLFeedSpider
spider, and it's intended to perform any last time processing required
before returning the results to the framework core, for example setting the
item IDs. It receives a list of results and the response which originated
those results. It must return a list of results (Items or Requests).
those results. It must return a list of results (items or requests).
XMLFeedSpider example

6
scrapy/commands/parse.py
View File

@ -1,11 +1,11 @@
import json
import logging
from itemadapter import is_item, ItemAdapter
from w3lib.url import is_url
from scrapy.commands import ScrapyCommand
from scrapy.http import Request
from scrapy.item import _BaseItem
from scrapy.utils import display
from scrapy.utils.conf import arglist_to_dict
from scrapy.utils.spider import iterate_spider_output, spidercls_for_request
@ -81,7 +81,7 @@ class Command(ScrapyCommand):
items = self.items.get(lvl, [])
print("# Scraped Items ", "-" * 60)
display.pprint([dict(x) for x in items], colorize=colour)
display.pprint([ItemAdapter(x).asdict() for x in items], colorize=colour)
def print_requests(self, lvl=None, colour=True):
if lvl is None:
@ -117,7 +117,7 @@ class Command(ScrapyCommand):
items, requests = [], []
for x in iterate_spider_output(callback(response, **cb_kwargs)):
if isinstance(x, (_BaseItem, dict)):
if is_item(x):
items.append(x)
elif isinstance(x, Request):
requests.append(x)

28
scrapy/contracts/default.py
View File

@ -1,10 +1,10 @@
import json
from scrapy.item import _BaseItem
from scrapy.http import Request
from scrapy.exceptions import ContractFail
from itemadapter import is_item, ItemAdapter
from scrapy.contracts import Contract
from scrapy.exceptions import ContractFail
from scrapy.http import Request
# contracts
@ -48,11 +48,11 @@ class ReturnsContract(Contract):
"""
name = 'returns'
objects = {
'request': Request,
'requests': Request,
'item': (_BaseItem, dict),
'items': (_BaseItem, dict),
object_type_verifiers = {
'request': lambda x: isinstance(x, Request),
'requests': lambda x: isinstance(x, Request),
'item': is_item,
'items': is_item,
}
def __init__(self, *args, **kwargs):
@ -64,7 +64,7 @@ class ReturnsContract(Contract):
% len(self.args)
)
self.obj_name = self.args[0] or None
self.obj_type = self.objects[self.obj_name]
self.obj_type_verifier = self.object_type_verifiers[self.obj_name]
try:
self.min_bound = int(self.args[1])
@ -79,7 +79,7 @@ class ReturnsContract(Contract):
def post_process(self, output):
occurrences = 0
for x in output:
if isinstance(x, self.obj_type):
if self.obj_type_verifier(x):
occurrences += 1
assertion = (self.min_bound <= occurrences <= self.max_bound)
@ -103,8 +103,8 @@ class ScrapesContract(Contract):
def post_process(self, output):
for x in output:
if isinstance(x, (_BaseItem, dict)):
missing = [arg for arg in self.args if arg not in x]
if is_item(x):
missing = [arg for arg in self.args if arg not in ItemAdapter(x)]
if missing:
raise ContractFail(
"Missing fields: %s" % ", ".join(missing))
missing_str = ", ".join(missing)
raise ContractFail("Missing fields: %s" % missing_str)

27
scrapy/core/scraper.py
View File

@ -4,18 +4,18 @@ extracts information from them"""
import logging
from collections import deque
from twisted.python.failure import Failure
from itemadapter import is_item
from twisted.internet import defer
from twisted.python.failure import Failure
from scrapy.utils.defer import defer_result, defer_succeed, parallel, iter_errback
from scrapy.utils.spider import iterate_spider_output
from scrapy.utils.misc import load_object, warn_on_generator_with_return_value
from scrapy.utils.log import logformatter_adapter, failure_to_exc_info
from scrapy.exceptions import CloseSpider, DropItem, IgnoreRequest
from scrapy import signals
from scrapy.http import Request, Response
from scrapy.item import _BaseItem
from scrapy.core.spidermw import SpiderMiddlewareManager
from scrapy.exceptions import CloseSpider, DropItem, IgnoreRequest
from scrapy.http import Request, Response
from scrapy.utils.defer import defer_result, defer_succeed, iter_errback, parallel
from scrapy.utils.log import failure_to_exc_info, logformatter_adapter
from scrapy.utils.misc import load_object, warn_on_generator_with_return_value
from scrapy.utils.spider import iterate_spider_output
logger = logging.getLogger(__name__)
@ -191,7 +191,7 @@ class Scraper:
"""
if isinstance(output, Request):
self.crawler.engine.crawl(request=output, spider=spider)
elif isinstance(output, (_BaseItem, dict)):
elif is_item(output):
self.slot.itemproc_size += 1
dfd = self.itemproc.process_item(output, spider)
dfd.addBoth(self._itemproc_finished, output, response, spider)
@ -200,10 +200,11 @@ class Scraper:
pass
else:
typename = type(output).__name__
logger.error('Spider must return Request, BaseItem, dict or None, '
'got %(typename)r in %(request)s',
{'request': request, 'typename': typename},
extra={'spider': spider})
logger.error(
'Spider must return request, item, or None, got %(typename)r in %(request)s',
{'request': request, 'typename': typename},
extra={'spider': spider},
)
def _log_download_errors(self, spider_failure, download_failure, request, spider):
"""Log and silence errors that come from the engine (typically download

38
scrapy/exporters.py
View File

@ -4,16 +4,18 @@ Item Exporters are used to export/serialize items into different formats.
import csv
import io
import pprint
import marshal
import warnings
import pickle
import pprint
import warnings
from xml.sax.saxutils import XMLGenerator
from scrapy.utils.serialize import ScrapyJSONEncoder
from scrapy.utils.python import to_bytes, to_unicode, is_listlike
from scrapy.item import _BaseItem
from itemadapter import is_item, ItemAdapter
from scrapy.exceptions import ScrapyDeprecationWarning
from scrapy.item import _BaseItem
from scrapy.utils.python import is_listlike, to_bytes, to_unicode
from scrapy.utils.serialize import ScrapyJSONEncoder
__all__ = ['BaseItemExporter', 'PprintItemExporter', 'PickleItemExporter',
@ -56,11 +58,14 @@ class BaseItemExporter:
"""Return the fields to export as an iterable of tuples
(name, serialized_value)
"""
item = ItemAdapter(item)
if include_empty is None:
include_empty = self.export_empty_fields
if self.fields_to_export is None:
if include_empty and not isinstance(item, dict):
field_iter = item.fields.keys()
if include_empty:
field_iter = item.field_names()
else:
field_iter = item.keys()
else:
@ -71,8 +76,8 @@ class BaseItemExporter:
for field_name in field_iter:
if field_name in item:
field = {} if isinstance(item, dict) else item.fields[field_name]
value = self.serialize_field(field, field_name, item[field_name])
field_meta = item.get_field_meta(field_name)
value = self.serialize_field(field_meta, field_name, item[field_name])
else:
value = default_value
@ -297,6 +302,7 @@ class PythonItemExporter(BaseItemExporter):
.. _msgpack: https://pypi.org/project/msgpack/
"""
def _configure(self, options, dont_fail=False):
self.binary = options.pop('binary', True)
super(PythonItemExporter, self)._configure(options, dont_fail)
@ -314,22 +320,22 @@ class PythonItemExporter(BaseItemExporter):
def _serialize_value(self, value):
if isinstance(value, _BaseItem):
return self.export_item(value)
if isinstance(value, dict):
return dict(self._serialize_dict(value))
if is_listlike(value):
elif is_item(value):
return dict(self._serialize_item(value))
elif is_listlike(value):
return [self._serialize_value(v) for v in value]
encode_func = to_bytes if self.binary else to_unicode
if isinstance(value, (str, bytes)):
return encode_func(value, encoding=self.encoding)
return value
def _serialize_dict(self, value):
for key, val in value.items():
def _serialize_item(self, item):
for key, value in ItemAdapter(item).items():
key = to_bytes(key) if self.binary else key
yield key, self._serialize_value(val)
yield key, self._serialize_value(value)
def export_item(self, item):
result = dict(self._get_serialized_fields(item))
if self.binary:
result = dict(self._serialize_dict(result))
result = dict(self._serialize_item(result))
return result

2
scrapy/item.py
View File

@ -36,7 +36,7 @@ class BaseItem(_BaseItem, metaclass=_BaseItemMeta):
"""
def __new__(cls, *args, **kwargs):
if issubclass(cls, BaseItem) and not (issubclass(cls, Item) or issubclass(cls, DictItem)):
if issubclass(cls, BaseItem) and not issubclass(cls, (Item, DictItem)):
warn('scrapy.item.BaseItem is deprecated, please use scrapy.item.Item instead',
ScrapyDeprecationWarning, stacklevel=2)
return super(BaseItem, cls).__new__(cls, *args, **kwargs)

18
scrapy/loader/__init__.py
View File

@ -6,6 +6,8 @@ See documentation in docs/topics/loaders.rst
from collections import defaultdict
from contextlib import suppress
from itemadapter import ItemAdapter
from scrapy.item import Item
from scrapy.loader.common import wrap_loader_context
from scrapy.loader.processors import Identity
@ -44,7 +46,7 @@ class ItemLoader:
self._local_item = context['item'] = item
self._local_values = defaultdict(list)
# values from initial item
for field_name, value in item.items():
for field_name, value in ItemAdapter(item).items():
self._values[field_name] += arg_to_iter(value)
@property
@ -127,13 +129,12 @@ class ItemLoader:
return value
def load_item(self):
item = self.item
adapter = ItemAdapter(self.item)
for field_name in tuple(self._values):
value = self.get_output_value(field_name)
if value is not None:
item[field_name] = value
return item
adapter[field_name] = value
return adapter.item
def get_output_value(self, field_name):
proc = self.get_output_processor(field_name)
@ -174,11 +175,8 @@ class ItemLoader:
value, type(e).__name__, str(e)))
def _get_item_field_attr(self, field_name, key, default=None):
if isinstance(self.item, Item):
value = self.item.fields[field_name].get(key, default)
else:
value = default
return value
field_meta = ItemAdapter(self.item).get_field_meta(field_name)
return field_meta.get(key, default)
def _check_selector_method(self):
if self.selector is None:

23
scrapy/pipelines/files.py
View File

@ -10,24 +10,26 @@ import mimetypes
import os
import time
from collections import defaultdict
from email.utils import parsedate_tz, mktime_tz
from contextlib import suppress
from email.utils import mktime_tz, parsedate_tz
from ftplib import FTP
from io import BytesIO
from urllib.parse import urlparse
from itemadapter import ItemAdapter
from twisted.internet import defer, threads
from scrapy.exceptions import IgnoreRequest, NotConfigured
from scrapy.http import Request
from scrapy.pipelines.media import MediaPipeline
from scrapy.settings import Settings
from scrapy.exceptions import NotConfigured, IgnoreRequest
from scrapy.http import Request
from scrapy.utils.misc import md5sum
from scrapy.utils.log import failure_to_exc_info
from scrapy.utils.python import to_bytes
from scrapy.utils.request import referer_str
from scrapy.utils.boto import is_botocore
from scrapy.utils.datatypes import CaselessDict
from scrapy.utils.ftp import ftp_store_file
from scrapy.utils.log import failure_to_exc_info
from scrapy.utils.misc import md5sum
from scrapy.utils.python import to_bytes
from scrapy.utils.request import referer_str
logger = logging.getLogger(__name__)
@ -517,7 +519,8 @@ class FilesPipeline(MediaPipeline):
# Overridable Interface
def get_media_requests(self, item, info):
return [Request(x) for x in item.get(self.files_urls_field, [])]
urls = ItemAdapter(item).get(self.files_urls_field, [])
return [Request(u) for u in urls]
def file_downloaded(self, response, request, info):
path = self.file_path(request, response=response, info=info)
@ -528,8 +531,8 @@ class FilesPipeline(MediaPipeline):
return checksum
def item_completed(self, results, item, info):
if isinstance(item, dict) or self.files_result_field in item.fields:
item[self.files_result_field] = [x for ok, x in results if ok]
with suppress(KeyError):
ItemAdapter(item)[self.files_result_field] = [x for ok, x in results if ok]
return item
def file_path(self, request, response=None, info=None):

19
scrapy/pipelines/images.py
View File

@ -5,17 +5,19 @@ See documentation in topics/media-pipeline.rst
"""
import functools
import hashlib
from contextlib import suppress
from io import BytesIO
from itemadapter import ItemAdapter
from PIL import Image
from scrapy.exceptions import DropItem
from scrapy.http import Request
from scrapy.pipelines.files import FileException, FilesPipeline
# TODO: from scrapy.pipelines.media import MediaPipeline
from scrapy.settings import Settings
from scrapy.utils.misc import md5sum
from scrapy.utils.python import to_bytes
from scrapy.http import Request
from scrapy.settings import Settings
from scrapy.exceptions import DropItem
# TODO: from scrapy.pipelines.media import MediaPipeline
from scrapy.pipelines.files import FileException, FilesPipeline
class NoimagesDrop(DropItem):
@ -157,11 +159,12 @@ class ImagesPipeline(FilesPipeline):
return image, buf
def get_media_requests(self, item, info):
return [Request(x) for x in item.get(self.images_urls_field, [])]
urls = ItemAdapter(item).get(self.images_urls_field, [])
return [Request(u) for u in urls]
def item_completed(self, results, item, info):
if isinstance(item, dict) or self.images_result_field in item.fields:
item[self.images_result_field] = [x for ok, x in results if ok]
with suppress(KeyError):
ItemAdapter(item)[self.images_result_field] = [x for ok, x in results if ok]
return item
def file_path(self, request, response=None, info=None):

11
scrapy/shell.py
View File

@ -6,6 +6,7 @@ See documentation in docs/topics/shell.rst
import os
import signal
from itemadapter import is_item
from twisted.internet import threads, defer
from twisted.python import threadable
from w3lib.url import any_to_uri
@ -13,20 +14,18 @@ from w3lib.url import any_to_uri
from scrapy.crawler import Crawler
from scrapy.exceptions import IgnoreRequest
from scrapy.http import Request, Response
from scrapy.item import _BaseItem
from scrapy.settings import Settings
from scrapy.spiders import Spider
from scrapy.utils.console import start_python_console
from scrapy.utils.conf import get_config
from scrapy.utils.console import DEFAULT_PYTHON_SHELLS, start_python_console
from scrapy.utils.datatypes import SequenceExclude
from scrapy.utils.misc import load_object
from scrapy.utils.response import open_in_browser
from scrapy.utils.conf import get_config
from scrapy.utils.console import DEFAULT_PYTHON_SHELLS
class Shell:
relevant_classes = (Crawler, Spider, Request, Response, _BaseItem, Settings)
relevant_classes = (Crawler, Spider, Request, Response, Settings)
def __init__(self, crawler, update_vars=None, code=None):
self.crawler = crawler
@ -154,7 +153,7 @@ class Shell:
return "\n".join("[s] %s" % line for line in b)
def _is_relevant(self, value):
return isinstance(value, self.relevant_classes)
return isinstance(value, self.relevant_classes) or is_item(value)
def inspect_response(response, spider):

2
scrapy/spiders/feed.py
View File

@ -31,7 +31,7 @@ class XMLFeedSpider(Spider):
processing required before returning the results to the framework core,
for example setting the item GUIDs. It receives a list of results and
the response which originated that results. It must return a list of
results (Items or Requests).
results (items or requests).
"""
return results

8
scrapy/templates/project/module/middlewares.py.tmpl
View File

@ -5,6 +5,9 @@
from scrapy import signals
# useful for handling different item types with a single interface
from itemadapter import is_item, ItemAdapter
class ${ProjectName}SpiderMiddleware:
# Not all methods need to be defined. If a method is not defined,
@ -29,7 +32,7 @@ class ${ProjectName}SpiderMiddleware:
# Called with the results returned from the Spider, after
# it has processed the response.
# Must return an iterable of Request, dict or Item objects.
# Must return an iterable of Request, or item objects.
for i in result:
yield i
@ -37,8 +40,7 @@ class ${ProjectName}SpiderMiddleware:
# Called when a spider or process_spider_input() method
# (from other spider middleware) raises an exception.
# Should return either None or an iterable of Request, dict
# or Item objects.
# Should return either None or an iterable of Request or item objects.
pass
def process_start_requests(self, start_requests, spider):

4
scrapy/templates/project/module/pipelines.py.tmpl
View File

@ -4,6 +4,10 @@
# See: https://docs.scrapy.org/en/latest/topics/item-pipeline.html
# useful for handling different item types with a single interface
from itemadapter import ItemAdapter
class ${ProjectName}Pipeline:
def process_item(self, item, spider):
return item

6
scrapy/utils/serialize.py
View File

@ -2,10 +2,10 @@ import json
import datetime
import decimal
from itemadapter import is_item, ItemAdapter
from twisted.internet import defer
from scrapy.http import Request, Response
from scrapy.item import _BaseItem
class ScrapyJSONEncoder(json.JSONEncoder):
@ -26,8 +26,8 @@ class ScrapyJSONEncoder(json.JSONEncoder):
return str(o)
elif isinstance(o, defer.Deferred):
return str(o)
elif isinstance(o, _BaseItem):
return dict(o)
elif is_item(o):
return ItemAdapter(o).asdict()
elif isinstance(o, Request):
return "<%s %s %s>" % (type(o).__name__, o.method, o.url)
elif isinstance(o, Response):

1
setup.py
View File

@ -80,6 +80,7 @@ setup(
'w3lib>=1.17.0',
'zope.interface>=4.1.3',
'protego>=0.1.15',
'itemadapter>=0.1.0',
],
extras_require=extras_require,
)

2
tests/requirements-py3.txt
View File

@ -1,4 +1,6 @@
# Tests requirements
attrs
dataclasses; python_version == '3.6'
jmespath
mitmproxy; python_version >= '3.6'
mitmproxy<4.0.0; python_version < '3.6'

40
tests/test_engine.py
View File

@ -16,9 +16,11 @@ import sys
from collections import defaultdict
from urllib.parse import urlparse
import attr
from itemadapter import ItemAdapter
from pydispatch import dispatcher
from testfixtures import LogCapture
from twisted.internet import reactor, defer
from twisted.internet import defer, reactor
from twisted.trial import unittest
from twisted.web import server, static, util
@ -32,7 +34,7 @@ from scrapy.spiders import Spider
from scrapy.utils.signal import disconnect_all
from scrapy.utils.test import get_crawler
from tests import tests_datadir, get_testdata
from tests import get_testdata, tests_datadir
class TestItem(Item):
@ -41,6 +43,13 @@ class TestItem(Item):
price = Field()
@attr.s
class AttrsItem:
name = attr.ib(default="")
url = attr.ib(default="")
price = attr.ib(default=0)
class TestSpider(Spider):
name = "scrapytest.org"
allowed_domains = ["scrapytest.org", "localhost"]
@ -79,6 +88,27 @@ class DictItemsSpider(TestSpider):
item_cls = dict
class AttrsItemsSpider(TestSpider):
item_class = AttrsItem
try:
from dataclasses import make_dataclass
except ImportError:
DataClassItemsSpider = None
else:
TestDataClass = make_dataclass("TestDataClass", [("name", str), ("url", str), ("price", int)])
class DataClassItemsSpider(DictItemsSpider):
def parse_item(self, response):
item = super().parse_item(response)
return TestDataClass(
name=item.get('name'),
url=item.get('url'),
price=item.get('price'),
)
class ItemZeroDivisionErrorSpider(TestSpider):
custom_settings = {
"ITEM_PIPELINES": {
@ -204,7 +234,10 @@ class EngineTest(unittest.TestCase):
@defer.inlineCallbacks
def test_crawler(self):
for spider in TestSpider, DictItemsSpider:
for spider in (TestSpider, DictItemsSpider, AttrsItemsSpider, DataClassItemsSpider):
if spider is None:
continue
self.run = CrawlerRun(spider)
yield self.run.run()
self._assert_visited_urls()
@ -281,6 +314,7 @@ class EngineTest(unittest.TestCase):
def _assert_scraped_items(self):
self.assertEqual(2, len(self.run.itemresp))
for item, response in self.run.itemresp:
item = ItemAdapter(item)
self.assertEqual(item['url'], response.url)
if 'item1.html' in item['url']:
self.assertEqual('Item 1 name', item['name'])

47
tests/test_loader.py
View File

@ -1,6 +1,9 @@
from functools import partial
import unittest
import attr
from itemadapter import ItemAdapter
from scrapy.http import HtmlResponse
from scrapy.item import Item, Field
from scrapy.loader import ItemLoader
@ -9,6 +12,13 @@ from scrapy.loader.processors import (Compose, Identity, Join,
from scrapy.selector import Selector
try:
from dataclasses import make_dataclass, field as dataclass_field
except ImportError:
make_dataclass = None
dataclass_field = None
# test items
class NameItem(Item):
name = Field()
@ -28,6 +38,11 @@ class TestNestedItem(Item):
image = Field()
@attr.s
class AttrsNameItem:
name = attr.ib(default="")
# test item loaders
class NameItemLoader(ItemLoader):
default_item_class = TestItem
@ -466,7 +481,7 @@ class InitializationTestMixin:
il = ItemLoader(item=input_item)
loaded_item = il.load_item()
self.assertIsInstance(loaded_item, self.item_class)
self.assertEqual(dict(loaded_item), {'name': ['foo']})
self.assertEqual(ItemAdapter(loaded_item).asdict(), {'name': ['foo']})
def test_keep_list(self):
"""Loaded item should contain values from the initial item"""
@ -474,7 +489,7 @@ class InitializationTestMixin:
il = ItemLoader(item=input_item)
loaded_item = il.load_item()
self.assertIsInstance(loaded_item, self.item_class)
self.assertEqual(dict(loaded_item), {'name': ['foo', 'bar']})
self.assertEqual(ItemAdapter(loaded_item).asdict(), {'name': ['foo', 'bar']})
def test_add_value_singlevalue_singlevalue(self):
"""Values added after initialization should be appended"""
@ -483,7 +498,7 @@ class InitializationTestMixin:
il.add_value('name', 'bar')
loaded_item = il.load_item()
self.assertIsInstance(loaded_item, self.item_class)
self.assertEqual(dict(loaded_item), {'name': ['foo', 'bar']})
self.assertEqual(ItemAdapter(loaded_item).asdict(), {'name': ['foo', 'bar']})
def test_add_value_singlevalue_list(self):
"""Values added after initialization should be appended"""
@ -492,7 +507,7 @@ class InitializationTestMixin:
il.add_value('name', ['item', 'loader'])
loaded_item = il.load_item()
self.assertIsInstance(loaded_item, self.item_class)
self.assertEqual(dict(loaded_item), {'name': ['foo', 'item', 'loader']})
self.assertEqual(ItemAdapter(loaded_item).asdict(), {'name': ['foo', 'item', 'loader']})
def test_add_value_list_singlevalue(self):
"""Values added after initialization should be appended"""
@ -501,7 +516,7 @@ class InitializationTestMixin:
il.add_value('name', 'qwerty')
loaded_item = il.load_item()
self.assertIsInstance(loaded_item, self.item_class)
self.assertEqual(dict(loaded_item), {'name': ['foo', 'bar', 'qwerty']})
self.assertEqual(ItemAdapter(loaded_item).asdict(), {'name': ['foo', 'bar', 'qwerty']})
def test_add_value_list_list(self):
"""Values added after initialization should be appended"""
@ -510,7 +525,7 @@ class InitializationTestMixin:
il.add_value('name', ['item', 'loader'])
loaded_item = il.load_item()
self.assertIsInstance(loaded_item, self.item_class)
self.assertEqual(dict(loaded_item), {'name': ['foo', 'bar', 'item', 'loader']})
self.assertEqual(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"""
@ -519,7 +534,7 @@ class InitializationTestMixin:
self.assertEqual(il.get_output_value('name'), ['foo'])
loaded_item = il.load_item()
self.assertIsInstance(loaded_item, self.item_class)
self.assertEqual(loaded_item, dict({'name': ['foo']}))
self.assertEqual(ItemAdapter(loaded_item).asdict(), dict({'name': ['foo']}))
def test_get_output_value_list(self):
"""Getting output value must not remove value from item"""
@ -528,7 +543,7 @@ class InitializationTestMixin:
self.assertEqual(il.get_output_value('name'), ['foo', 'bar'])
loaded_item = il.load_item()
self.assertIsInstance(loaded_item, self.item_class)
self.assertEqual(loaded_item, dict({'name': ['foo', 'bar']}))
self.assertEqual(ItemAdapter(loaded_item).asdict(), dict({'name': ['foo', 'bar']}))
def test_values_single(self):
"""Values from initial item must be added to loader._values"""
@ -551,6 +566,22 @@ class InitializationFromItemTest(InitializationTestMixin, unittest.TestCase):
item_class = NameItem
class InitializationFromAttrsItemTest(InitializationTestMixin, unittest.TestCase):
item_class = AttrsNameItem
@unittest.skipIf(not make_dataclass, "dataclasses module is not available")
class InitializationFromDataClassTest(InitializationTestMixin, unittest.TestCase):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
if make_dataclass:
self.item_class = make_dataclass(
"TestDataClass",
[("name", list, dataclass_field(default_factory=list))],
)
class BaseNoInputReprocessingLoader(ItemLoader):
title_in = MapCompose(str.upper)
title_out = TakeFirst()

144
tests/test_pipeline_files.py
View File

@ -2,22 +2,41 @@ import os
import random
import time
from io import BytesIO
from tempfile import mkdtemp
from shutil import rmtree
from unittest import mock
from tempfile import mkdtemp
from unittest import mock, skipIf
from urllib.parse import urlparse
from twisted.trial import unittest
import attr
from itemadapter import ItemAdapter
from twisted.internet import defer
from twisted.trial import unittest
from scrapy.pipelines.files import FilesPipeline, FSFilesStore, S3FilesStore, GCSFilesStore, FTPFilesStore
from scrapy.item import Item, Field
from scrapy.http import Request, Response
from scrapy.item import Field, Item
from scrapy.pipelines.files import (
FilesPipeline,
FSFilesStore,
FTPFilesStore,
GCSFilesStore,
S3FilesStore,
)
from scrapy.settings import Settings
from scrapy.utils.test import assert_aws_environ, get_s3_content_and_delete
from scrapy.utils.test import assert_gcs_environ, get_gcs_content_and_delete
from scrapy.utils.test import get_ftp_content_and_delete
from scrapy.utils.boto import is_botocore
from scrapy.utils.test import (
assert_aws_environ,
assert_gcs_environ,
get_ftp_content_and_delete,
get_gcs_content_and_delete,
get_s3_content_and_delete,
)
try:
from dataclasses import make_dataclass, field as dataclass_field
except ImportError:
make_dataclass = None
dataclass_field = None
def _mocked_download_func(request, info):
@ -143,43 +162,88 @@ class FilesPipelineTestCase(unittest.TestCase):
p.stop()
class FilesPipelineTestCaseFields(unittest.TestCase):
class FilesPipelineTestCaseFieldsMixin:
def test_item_fields_default(self):
class TestItem(Item):
name = Field()
file_urls = Field()
files = Field()
for cls in TestItem, dict:
url = 'http://www.example.com/files/1.txt'
item = cls({'name': 'item1', 'file_urls': [url]})
pipeline = FilesPipeline.from_settings(Settings({'FILES_STORE': 's3://example/files/'}))
requests = list(pipeline.get_media_requests(item, None))
self.assertEqual(requests[0].url, url)
results = [(True, {'url': url})]
pipeline.item_completed(results, item, None)
self.assertEqual(item['files'], [results[0][1]])
url = 'http://www.example.com/files/1.txt'
item = self.item_class(name='item1', file_urls=[url])
pipeline = FilesPipeline.from_settings(Settings({'FILES_STORE': 's3://example/files/'}))
requests = list(pipeline.get_media_requests(item, None))
self.assertEqual(requests[0].url, url)
results = [(True, {'url': url})]
item = pipeline.item_completed(results, item, None)
files = ItemAdapter(item).get("files")
self.assertEqual(files, [results[0][1]])
self.assertIsInstance(item, self.item_class)
def test_item_fields_override_settings(self):
class TestItem(Item):
name = Field()
files = Field()
stored_file = Field()
url = 'http://www.example.com/files/1.txt'
item = self.item_class(name='item1', custom_file_urls=[url])
pipeline = FilesPipeline.from_settings(Settings({
'FILES_STORE': 's3://example/files/',
'FILES_URLS_FIELD': 'custom_file_urls',
'FILES_RESULT_FIELD': 'custom_files'
}))
requests = list(pipeline.get_media_requests(item, None))
self.assertEqual(requests[0].url, url)
results = [(True, {'url': url})]
item = pipeline.item_completed(results, item, None)
custom_files = ItemAdapter(item).get("custom_files")
self.assertEqual(custom_files, [results[0][1]])
self.assertIsInstance(item, self.item_class)
for cls in TestItem, dict:
url = 'http://www.example.com/files/1.txt'
item = cls({'name': 'item1', 'files': [url]})
pipeline = FilesPipeline.from_settings(Settings({
'FILES_STORE': 's3://example/files/',
'FILES_URLS_FIELD': 'files',
'FILES_RESULT_FIELD': 'stored_file'
}))
requests = list(pipeline.get_media_requests(item, None))
self.assertEqual(requests[0].url, url)
results = [(True, {'url': url})]
pipeline.item_completed(results, item, None)
self.assertEqual(item['stored_file'], [results[0][1]])
class FilesPipelineTestCaseFieldsDict(FilesPipelineTestCaseFieldsMixin, unittest.TestCase):
item_class = dict
class FilesPipelineTestItem(Item):
name = Field()
# default fields
file_urls = Field()
files = Field()
# overridden fields
custom_file_urls = Field()
custom_files = Field()
class FilesPipelineTestCaseFieldsItem(FilesPipelineTestCaseFieldsMixin, unittest.TestCase):
item_class = FilesPipelineTestItem
@skipIf(not make_dataclass, "dataclasses module is not available")
class FilesPipelineTestCaseFieldsDataClass(FilesPipelineTestCaseFieldsMixin, unittest.TestCase):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
if make_dataclass:
self.item_class = make_dataclass(
"FilesPipelineTestDataClass",
[
("name", str),
# default fields
("file_urls", list, dataclass_field(default_factory=list)),
("files", list, dataclass_field(default_factory=list)),
# overridden fields
("custom_file_urls", list, dataclass_field(default_factory=list)),
("custom_files", list, dataclass_field(default_factory=list)),
],
)
@attr.s
class FilesPipelineTestAttrsItem:
name = attr.ib(default="")
# default fields
file_urls = attr.ib(default=lambda: [])
files = attr.ib(default=lambda: [])
# overridden fields
custom_file_urls = attr.ib(default=lambda: [])
custom_files = attr.ib(default=lambda: [])
class FilesPipelineTestCaseFieldsAttrsItem(FilesPipelineTestCaseFieldsMixin, unittest.TestCase):
item_class = FilesPipelineTestAttrsItem
class FilesPipelineTestCaseCustomSettings(unittest.TestCase):

129
tests/test_pipeline_images.py
View File

@ -1,17 +1,28 @@
import io
import hashlib
import io
import random
from tempfile import mkdtemp
from shutil import rmtree
from tempfile import mkdtemp
from unittest import skipIf
import attr
from itemadapter import ItemAdapter
from twisted.trial import unittest
from scrapy.item import Item, Field
from scrapy.http import Request, Response
from scrapy.settings import Settings
from scrapy.item import Field, Item
from scrapy.pipelines.images import ImagesPipeline
from scrapy.settings import Settings
from scrapy.utils.python import to_bytes
try:
from dataclasses import make_dataclass, field as dataclass_field
except ImportError:
make_dataclass = None
dataclass_field = None
skip = False
try:
from PIL import Image
@ -124,43 +135,89 @@ class DeprecatedImagesPipeline(ImagesPipeline):
return 'thumbsup/%s/%s.jpg' % (thumb_id, thumb_guid)
class ImagesPipelineTestCaseFields(unittest.TestCase):
class ImagesPipelineTestCaseFieldsMixin:
def test_item_fields_default(self):
class TestItem(Item):
name = Field()
image_urls = Field()
images = Field()
for cls in TestItem, dict:
url = 'http://www.example.com/images/1.jpg'
item = cls({'name': 'item1', 'image_urls': [url]})
pipeline = ImagesPipeline.from_settings(Settings({'IMAGES_STORE': 's3://example/images/'}))
requests = list(pipeline.get_media_requests(item, None))
self.assertEqual(requests[0].url, url)
results = [(True, {'url': url})]
pipeline.item_completed(results, item, None)
self.assertEqual(item['images'], [results[0][1]])
url = 'http://www.example.com/images/1.jpg'
item = self.item_class(name='item1', image_urls=[url])
pipeline = ImagesPipeline.from_settings(Settings({'IMAGES_STORE': 's3://example/images/'}))
requests = list(pipeline.get_media_requests(item, None))
self.assertEqual(requests[0].url, url)
results = [(True, {'url': url})]
item = pipeline.item_completed(results, item, None)
images = ItemAdapter(item).get("images")
self.assertEqual(images, [results[0][1]])
self.assertIsInstance(item, self.item_class)
def test_item_fields_override_settings(self):
class TestItem(Item):
name = Field()
image = Field()
stored_image = Field()
url = 'http://www.example.com/images/1.jpg'
item = self.item_class(name='item1', custom_image_urls=[url])
pipeline = ImagesPipeline.from_settings(Settings({
'IMAGES_STORE': 's3://example/images/',
'IMAGES_URLS_FIELD': 'custom_image_urls',
'IMAGES_RESULT_FIELD': 'custom_images'
}))
requests = list(pipeline.get_media_requests(item, None))
self.assertEqual(requests[0].url, url)
results = [(True, {'url': url})]
item = pipeline.item_completed(results, item, None)
custom_images = ItemAdapter(item).get("custom_images")
self.assertEqual(custom_images, [results[0][1]])
self.assertIsInstance(item, self.item_class)
for cls in TestItem, dict:
url = 'http://www.example.com/images/1.jpg'
item = cls({'name': 'item1', 'image': [url]})
pipeline = ImagesPipeline.from_settings(Settings({
'IMAGES_STORE': 's3://example/images/',
'IMAGES_URLS_FIELD': 'image',
'IMAGES_RESULT_FIELD': 'stored_image'
}))
requests = list(pipeline.get_media_requests(item, None))
self.assertEqual(requests[0].url, url)
results = [(True, {'url': url})]
pipeline.item_completed(results, item, None)
self.assertEqual(item['stored_image'], [results[0][1]])
class ImagesPipelineTestCaseFieldsDict(ImagesPipelineTestCaseFieldsMixin, unittest.TestCase):
item_class = dict
class ImagesPipelineTestItem(Item):
name = Field()
# default fields
image_urls = Field()
images = Field()
# overridden fields
custom_image_urls = Field()
custom_images = Field()
class ImagesPipelineTestCaseFieldsItem(ImagesPipelineTestCaseFieldsMixin, unittest.TestCase):
item_class = ImagesPipelineTestItem
@skipIf(not make_dataclass, "dataclasses module is not available")
class ImagesPipelineTestCaseFieldsDataClass(ImagesPipelineTestCaseFieldsMixin, unittest.TestCase):
item_class = None
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
if make_dataclass:
self.item_class = make_dataclass(
"FilesPipelineTestDataClass",
[
("name", str),
# default fields
("image_urls", list, dataclass_field(default_factory=list)),
("images", list, dataclass_field(default_factory=list)),
# overridden fields
("custom_image_urls", list, dataclass_field(default_factory=list)),
("custom_images", list, dataclass_field(default_factory=list)),
],
)
@attr.s
class ImagesPipelineTestAttrsItem:
name = attr.ib(default="")
# default fields
image_urls = attr.ib(default=lambda: [])
images = attr.ib(default=lambda: [])
# overridden fields
custom_image_urls = attr.ib(default=lambda: [])
custom_images = attr.ib(default=lambda: [])
class ImagesPipelineTestCaseFieldsAttrsItem(ImagesPipelineTestCaseFieldsMixin, unittest.TestCase):
item_class = ImagesPipelineTestAttrsItem
class ImagesPipelineTestCaseCustomSettings(unittest.TestCase):

43
tests/test_utils_serialize.py
View File

@ -1,18 +1,25 @@
import datetime
import json
import unittest
import datetime
from decimal import Decimal
import attr
from twisted.internet import defer
from scrapy.utils.serialize import ScrapyJSONEncoder
from scrapy.http import Request, Response
from scrapy.utils.serialize import ScrapyJSONEncoder
try:
from dataclasses import make_dataclass
except ImportError:
make_dataclass = None
class JsonEncoderTestCase(unittest.TestCase):
def setUp(self):
self.encoder = ScrapyJSONEncoder()
self.encoder = ScrapyJSONEncoder(sort_keys=True)
def test_encode_decode(self):
dt = datetime.datetime(2010, 1, 2, 10, 11, 12)
@ -31,7 +38,8 @@ class JsonEncoderTestCase(unittest.TestCase):
for input, output in [('foo', 'foo'), (d, ds), (t, ts), (dt, dts),
(dec, decs), (['foo', d], ['foo', ds]), (s, ss),
(dt_set, dt_sets)]:
self.assertEqual(self.encoder.encode(input), json.dumps(output))
self.assertEqual(self.encoder.encode(input),
json.dumps(output, sort_keys=True))
def test_encode_deferred(self):
self.assertIn('Deferred', self.encoder.encode(defer.Deferred()))
@ -47,3 +55,30 @@ class JsonEncoderTestCase(unittest.TestCase):
rs = self.encoder.encode(r)
self.assertIn(r.url, rs)
self.assertIn(str(r.status), rs)
@unittest.skipIf(not make_dataclass, "No dataclass support")
def test_encode_dataclass_item(self):
TestDataClass = make_dataclass(
"TestDataClass",
[("name", str), ("url", str), ("price", int)],
)
item = TestDataClass(name="Product", url="http://product.org", price=1)
encoded = self.encoder.encode(item)
self.assertEqual(
encoded,
'{"name": "Product", "price": 1, "url": "http://product.org"}'
)
def test_encode_attrs_item(self):
@attr.s
class AttrsItem:
name = attr.ib(type=str)
url = attr.ib(type=str)
price = attr.ib(type=int)
item = AttrsItem(name="Product", url="http://product.org", price=1)
encoded = self.encoder.encode(item)
self.assertEqual(
encoded,
'{"name": "Product", "price": 1, "url": "http://product.org"}'
)

3
tox.ini
View File

@ -37,7 +37,7 @@ deps =
pytest-flake8
commands =
py.test --flake8 {posargs:docs scrapy tests}
[testenv:pylint]
basepython = python3
deps =
@ -62,6 +62,7 @@ deps =
-ctests/constraints.txt
cryptography==2.0
cssselect==0.9.1
itemadapter==0.1.0
lxml==3.5.0
parsel==1.5.0
Protego==0.1.15