From d7deba7e89242774ae712d87eb7bb331759a731f Mon Sep 17 00:00:00 2001 From: Marlena Chatzigrigoriou <56519084+marlenachatzigrigoriou@users.noreply.github.com> Date: Wed, 14 Jul 2021 11:34:28 +0300 Subject: [PATCH] Document all import paths and use the shortest in examples (#5099) --- docs/faq.rst | 4 +- docs/intro/tutorial.rst | 32 +++++++-------- docs/topics/api.rst | 4 +- docs/topics/contracts.rst | 4 +- docs/topics/coroutines.rst | 2 +- docs/topics/debug.rst | 2 +- docs/topics/developer-tools.rst | 2 +- docs/topics/downloader-middleware.rst | 58 +++++++++++++-------------- docs/topics/dynamic-content.rst | 14 +++---- docs/topics/exporters.rst | 4 +- docs/topics/feed-exports.rst | 4 +- docs/topics/item-pipeline.rst | 6 +-- docs/topics/items.rst | 10 +++-- docs/topics/jobs.rst | 4 +- docs/topics/leaks.rst | 16 ++++---- docs/topics/logging.rst | 2 +- docs/topics/media-pipeline.rst | 6 +-- docs/topics/request-response.rst | 16 ++++---- docs/topics/selectors.rst | 8 ++-- docs/topics/settings.rst | 16 ++++---- docs/topics/shell.rst | 8 ++-- docs/topics/signals.rst | 54 ++++++++++++------------- docs/topics/spider-middleware.rst | 26 ++++++------ docs/topics/spiders.rst | 43 ++++++++++---------- 24 files changed, 175 insertions(+), 170 deletions(-) diff --git a/docs/faq.rst b/docs/faq.rst index 9709885f6..16903daea 100644 --- a/docs/faq.rst +++ b/docs/faq.rst @@ -149,7 +149,7 @@ How can I prevent memory errors due to many allowed domains? ------------------------------------------------------------ If you have a spider with a long list of -:attr:`~scrapy.spiders.Spider.allowed_domains` (e.g. 50,000+), consider +:attr:`~scrapy.Spider.allowed_domains` (e.g. 50,000+), consider replacing the default :class:`~scrapy.spidermiddlewares.offsite.OffsiteMiddleware` spider middleware with a :ref:`custom spider middleware ` that requires @@ -157,7 +157,7 @@ less memory. For example: - If your domain names are similar enough, use your own regular expression instead joining the strings in - :attr:`~scrapy.spiders.Spider.allowed_domains` into a complex regular + :attr:`~scrapy.Spider.allowed_domains` into a complex regular expression. - If you can `meet the installation requirements`_, use pyre2_ instead of diff --git a/docs/intro/tutorial.rst b/docs/intro/tutorial.rst index 740e47d0c..438f3d6df 100644 --- a/docs/intro/tutorial.rst +++ b/docs/intro/tutorial.rst @@ -78,7 +78,7 @@ Our first Spider Spiders are classes that you define and that Scrapy uses to scrape information from a website (or a group of websites). They must subclass -:class:`~scrapy.spiders.Spider` and define the initial requests to make, +:class:`~scrapy.Spider` and define the initial requests to make, optionally how to follow links in the pages, and how to parse the downloaded page content to extract data. @@ -107,26 +107,26 @@ This is the code for our first Spider. Save it in a file named self.log(f'Saved file {filename}') -As you can see, our Spider subclasses :class:`scrapy.Spider ` +As you can see, our Spider subclasses :class:`scrapy.Spider ` and defines some attributes and methods: -* :attr:`~scrapy.spiders.Spider.name`: identifies the Spider. It must be +* :attr:`~scrapy.Spider.name`: identifies the Spider. It must be unique within a project, that is, you can't set the same name for different Spiders. -* :meth:`~scrapy.spiders.Spider.start_requests`: must return an iterable of +* :meth:`~scrapy.Spider.start_requests`: must return an iterable of Requests (you can return a list of requests or write a generator function) which the Spider will begin to crawl from. Subsequent requests will be generated successively from these initial requests. -* :meth:`~scrapy.spiders.Spider.parse`: a method that will be called to handle +* :meth:`~scrapy.Spider.parse`: a method that will be called to handle the response downloaded for each of the requests made. The response parameter is an instance of :class:`~scrapy.http.TextResponse` that holds the page content and has further helpful methods to handle it. - The :meth:`~scrapy.spiders.Spider.parse` method usually parses the response, extracting + The :meth:`~scrapy.Spider.parse` method usually parses the response, extracting the scraped data as dicts and also finding new URLs to - follow and creating new requests (:class:`~scrapy.http.Request`) from them. + follow and creating new requests (:class:`~scrapy.Request`) from them. How to run our spider --------------------- @@ -162,7 +162,7 @@ for the respective URLs, as our ``parse`` method instructs. What just happened under the hood? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -Scrapy schedules the :class:`scrapy.Request ` objects +Scrapy schedules the :class:`scrapy.Request ` objects returned by the ``start_requests`` method of the Spider. Upon receiving a response for each one, it instantiates :class:`~scrapy.http.Response` objects and calls the callback method associated with the request (in this case, the @@ -171,11 +171,11 @@ and calls the callback method associated with the request (in this case, the A shortcut to the start_requests method --------------------------------------- -Instead of implementing a :meth:`~scrapy.spiders.Spider.start_requests` method -that generates :class:`scrapy.Request ` objects from URLs, -you can just define a :attr:`~scrapy.spiders.Spider.start_urls` class attribute +Instead of implementing a :meth:`~scrapy.Spider.start_requests` method +that generates :class:`scrapy.Request ` objects from URLs, +you can just define a :attr:`~scrapy.Spider.start_urls` class attribute with a list of URLs. This list will then be used by the default implementation -of :meth:`~scrapy.spiders.Spider.start_requests` to create the initial requests +of :meth:`~scrapy.Spider.start_requests` to create the initial requests for your spider:: import scrapy @@ -194,9 +194,9 @@ for your spider:: with open(filename, 'wb') as f: f.write(response.body) -The :meth:`~scrapy.spiders.Spider.parse` method will be called to handle each +The :meth:`~scrapy.Spider.parse` method will be called to handle each of the requests for those URLs, even though we haven't explicitly told Scrapy -to do so. This happens because :meth:`~scrapy.spiders.Spider.parse` is Scrapy's +to do so. This happens because :meth:`~scrapy.Spider.parse` is Scrapy's default callback method, which is called for requests without an explicitly assigned callback. @@ -248,7 +248,7 @@ object: The result of running ``response.css('title')`` is a list-like object called :class:`~scrapy.selector.SelectorList`, which represents a list of -:class:`~scrapy.selector.Selector` objects that wrap around XML/HTML elements +:class:`~scrapy.Selector` objects that wrap around XML/HTML elements and allow you to run further queries to fine-grain the selection or extract the data. @@ -670,7 +670,7 @@ the pagination links with the ``parse`` callback as we saw before. Here we're passing callbacks to :meth:`response.follow_all ` as positional arguments to make the code shorter; it also works for -:class:`~scrapy.http.Request`. +:class:`~scrapy.Request`. The ``parse_author`` callback defines a helper function to extract and cleanup the data from a CSS query and yields the Python dict with the author data. diff --git a/docs/topics/api.rst b/docs/topics/api.rst index 445b2979f..900b19c7a 100644 --- a/docs/topics/api.rst +++ b/docs/topics/api.rst @@ -29,7 +29,7 @@ how you :ref:`configure the downloader middlewares .. class:: Crawler(spidercls, settings) The Crawler object must be instantiated with a - :class:`scrapy.spiders.Spider` subclass and a + :class:`scrapy.Spider` subclass and a :class:`scrapy.settings.Settings` object. .. attribute:: settings @@ -196,7 +196,7 @@ SpiderLoader API match the request's url against the domains of the spiders. :param request: queried request - :type request: :class:`~scrapy.http.Request` instance + :type request: :class:`~scrapy.Request` instance .. _topics-api-signals: diff --git a/docs/topics/contracts.rst b/docs/topics/contracts.rst index e61421bf1..ef296dc9e 100644 --- a/docs/topics/contracts.rst +++ b/docs/topics/contracts.rst @@ -37,7 +37,7 @@ This callback is tested using three built-in contracts: .. class:: CallbackKeywordArgumentsContract - This contract (``@cb_kwargs``) sets the :attr:`cb_kwargs ` + This contract (``@cb_kwargs``) sets the :attr:`cb_kwargs ` attribute for the sample request. It must be a valid JSON dictionary. :: @@ -88,7 +88,7 @@ override three methods: .. method:: Contract.adjust_request_args(args) This receives a ``dict`` as an argument containing default arguments - for request object. :class:`~scrapy.http.Request` is used by default, + for request object. :class:`~scrapy.Request` is used by default, but this can be changed with the ``request_cls`` attribute. If multiple contracts in chain have this attribute defined, the last one is used. diff --git a/docs/topics/coroutines.rst b/docs/topics/coroutines.rst index 3b1549bd3..0904637b0 100644 --- a/docs/topics/coroutines.rst +++ b/docs/topics/coroutines.rst @@ -15,7 +15,7 @@ Supported callables The following callables may be defined as coroutines using ``async def``, and hence use coroutine syntax (e.g. ``await``, ``async for``, ``async with``): -- :class:`~scrapy.http.Request` callbacks. +- :class:`~scrapy.Request` callbacks. .. note:: The callback output is not processed until the whole callback finishes. diff --git a/docs/topics/debug.rst b/docs/topics/debug.rst index d75f17301..4d452b4df 100644 --- a/docs/topics/debug.rst +++ b/docs/topics/debug.rst @@ -36,7 +36,7 @@ Consider the following Scrapy spider below:: Basically this is a simple spider which parses two pages of items (the start_urls). Items also have a details page with additional information, so we -use the ``cb_kwargs`` functionality of :class:`~scrapy.http.Request` to pass a +use the ``cb_kwargs`` functionality of :class:`~scrapy.Request` to pass a partially populated item. diff --git a/docs/topics/developer-tools.rst b/docs/topics/developer-tools.rst index c83b1a9d9..057b1ec62 100644 --- a/docs/topics/developer-tools.rst +++ b/docs/topics/developer-tools.rst @@ -274,7 +274,7 @@ In more complex websites, it could be difficult to easily reproduce the requests, as we could need to add ``headers`` or ``cookies`` to make it work. In those cases you can export the requests in `cURL `_ format, by right-clicking on each of them in the network tool and using the -:meth:`~scrapy.http.Request.from_curl()` method to generate an equivalent +:meth:`~scrapy.Request.from_curl()` method to generate an equivalent request:: from scrapy import Request diff --git a/docs/topics/downloader-middleware.rst b/docs/topics/downloader-middleware.rst index b539c23df..80c6c2c37 100644 --- a/docs/topics/downloader-middleware.rst +++ b/docs/topics/downloader-middleware.rst @@ -76,7 +76,7 @@ object gives you access, for example, to the :ref:`settings `. middleware. :meth:`process_request` should either: return ``None``, return a - :class:`~scrapy.http.Response` object, return a :class:`~scrapy.http.Request` + :class:`~scrapy.Response` object, return a :class:`~scrapy.http.Request` object, or raise :exc:`~scrapy.exceptions.IgnoreRequest`. If it returns ``None``, Scrapy will continue processing this request, executing all @@ -88,7 +88,7 @@ object gives you access, for example, to the :ref:`settings `. or the appropriate download function; it'll return that response. The :meth:`process_response` methods of installed middleware is always called on every response. - If it returns a :class:`~scrapy.http.Request` object, Scrapy will stop calling + If it returns a :class:`~scrapy.Request` object, Scrapy will stop calling process_request methods and reschedule the returned request. Once the newly returned request is performed, the appropriate middleware chain will be called on the downloaded response. @@ -100,22 +100,22 @@ object gives you access, for example, to the :ref:`settings `. ignored and not logged (unlike other exceptions). :param request: the request being processed - :type request: :class:`~scrapy.http.Request` object + :type request: :class:`~scrapy.Request` object :param spider: the spider for which this request is intended - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. method:: process_response(request, response, spider) :meth:`process_response` should either: return a :class:`~scrapy.http.Response` - object, return a :class:`~scrapy.http.Request` object or + object, return a :class:`~scrapy.Request` object or raise a :exc:`~scrapy.exceptions.IgnoreRequest` exception. If it returns a :class:`~scrapy.http.Response` (it could be the same given response, or a brand-new one), that response will continue to be processed with the :meth:`process_response` of the next middleware in the chain. - If it returns a :class:`~scrapy.http.Request` object, the middleware chain is + If it returns a :class:`~scrapy.Request` object, the middleware chain is halted and the returned request is rescheduled to be downloaded in the future. This is the same behavior as if a request is returned from :meth:`process_request`. @@ -124,13 +124,13 @@ object gives you access, for example, to the :ref:`settings `. exception, it is ignored and not logged (unlike other exceptions). :param request: the request that originated the response - :type request: is a :class:`~scrapy.http.Request` object + :type request: is a :class:`~scrapy.Request` object :param response: the response being processed :type response: :class:`~scrapy.http.Response` object :param spider: the spider for which this response is intended - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. method:: process_exception(request, exception, spider) @@ -139,7 +139,7 @@ object gives you access, for example, to the :ref:`settings `. exception (including an :exc:`~scrapy.exceptions.IgnoreRequest` exception) :meth:`process_exception` should return: either ``None``, - a :class:`~scrapy.http.Response` object, or a :class:`~scrapy.http.Request` object. + a :class:`~scrapy.http.Response` object, or a :class:`~scrapy.Request` object. If it returns ``None``, Scrapy will continue processing this exception, executing any other :meth:`process_exception` methods of installed middleware, @@ -149,19 +149,19 @@ object gives you access, for example, to the :ref:`settings `. method chain of installed middleware is started, and Scrapy won't bother calling any other :meth:`process_exception` methods of middleware. - If it returns a :class:`~scrapy.http.Request` object, the returned request is + If it returns a :class:`~scrapy.Request` object, the returned request is rescheduled to be downloaded in the future. This stops the execution of :meth:`process_exception` methods of the middleware the same as returning a response would. :param request: the request that generated the exception - :type request: is a :class:`~scrapy.http.Request` object + :type request: is a :class:`~scrapy.Request` object :param exception: the raised exception :type exception: an ``Exception`` object :param spider: the spider for which this request is intended - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. method:: from_crawler(cls, crawler) @@ -203,13 +203,13 @@ CookiesMiddleware browsers do. .. caution:: When non-UTF8 encoded byte sequences are passed to a - :class:`~scrapy.http.Request`, the ``CookiesMiddleware`` will log + :class:`~scrapy.Request`, the ``CookiesMiddleware`` will log a warning. Refer to :ref:`topics-logging-advanced-customization` to customize the logging behaviour. .. caution:: Cookies set via the ``Cookie`` header are not considered by the :ref:`cookies-mw`. If you need to set cookies for a request, use the - :class:`Request.cookies ` parameter. This is a known + :class:`Request.cookies ` parameter. This is a known current limitation that is being worked on. The following settings can be used to configure the cookie middleware: @@ -258,7 +258,7 @@ web server and received cookies in :class:`~scrapy.http.Response` will **not** be merged with the existing cookies. For more detailed information see the ``cookies`` parameter in -:class:`~scrapy.http.Request`. +:class:`~scrapy.Request`. .. setting:: COOKIES_DEBUG @@ -501,7 +501,7 @@ defines the methods described below. the :signal:`open_spider ` signal. :param spider: the spider which has been opened - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. method:: close_spider(spider) @@ -509,27 +509,27 @@ defines the methods described below. the :signal:`close_spider ` signal. :param spider: the spider which has been closed - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. method:: retrieve_response(spider, request) Return response if present in cache, or ``None`` otherwise. :param spider: the spider which generated the request - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object :param request: the request to find cached response for - :type request: :class:`~scrapy.http.Request` object + :type request: :class:`~scrapy.Request` object .. method:: store_response(spider, request, response) Store the given response in the cache. :param spider: the spider for which the response is intended - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object :param request: the corresponding request the spider generated - :type request: :class:`~scrapy.http.Request` object + :type request: :class:`~scrapy.Request` object :param response: the response to store in the cache :type response: :class:`~scrapy.http.Response` object @@ -722,7 +722,7 @@ HttpProxyMiddleware .. class:: HttpProxyMiddleware This middleware sets the HTTP proxy to use for requests, by setting the - ``proxy`` meta value for :class:`~scrapy.http.Request` objects. + ``proxy`` meta value for :class:`~scrapy.Request` objects. Like the Python standard library module :mod:`urllib.request`, it obeys the following environment variables: @@ -749,12 +749,12 @@ RedirectMiddleware .. reqmeta:: redirect_urls The urls which the request goes through (while being redirected) can be found -in the ``redirect_urls`` :attr:`Request.meta ` key. +in the ``redirect_urls`` :attr:`Request.meta ` key. .. reqmeta:: redirect_reasons The reason behind each redirect in :reqmeta:`redirect_urls` can be found in the -``redirect_reasons`` :attr:`Request.meta ` key. For +``redirect_reasons`` :attr:`Request.meta ` key. For example: ``[301, 302, 307, 'meta refresh']``. The format of a reason depends on the middleware that handled the corresponding @@ -770,7 +770,7 @@ settings (see the settings documentation for more info): .. reqmeta:: dont_redirect -If :attr:`Request.meta ` has ``dont_redirect`` +If :attr:`Request.meta ` has ``dont_redirect`` key set to True, the request will be ignored by this middleware. If you want to handle some redirect status codes in your spider, you can @@ -783,7 +783,7 @@ responses (and pass them through to your spider) you can do this:: handle_httpstatus_list = [301, 302] The ``handle_httpstatus_list`` key of :attr:`Request.meta -` can also be used to specify which response codes to +` can also be used to specify which response codes to allow on a per-request basis. You can also set the meta key ``handle_httpstatus_all`` to ``True`` if you want to allow any response code for a request. @@ -889,7 +889,7 @@ settings (see the settings documentation for more info): .. reqmeta:: dont_retry -If :attr:`Request.meta ` has ``dont_retry`` key +If :attr:`Request.meta ` has ``dont_retry`` key set to True, the request will be ignored by this middleware. To retry requests from a spider callback, you can use the @@ -919,7 +919,7 @@ Default: ``2`` Maximum number of times to retry, in addition to the first download. Maximum number of retries can also be specified per-request using -:reqmeta:`max_retry_times` attribute of :attr:`Request.meta `. +:reqmeta:`max_retry_times` attribute of :attr:`Request.meta `. When initialized, the :reqmeta:`max_retry_times` meta key takes higher precedence over the :setting:`RETRY_TIMES` setting. @@ -986,7 +986,7 @@ RobotsTxtMiddleware .. reqmeta:: dont_obey_robotstxt -If :attr:`Request.meta ` has +If :attr:`Request.meta ` has ``dont_obey_robotstxt`` key set to True the request will be ignored by this middleware even if :setting:`ROBOTSTXT_OBEY` is enabled. diff --git a/docs/topics/dynamic-content.rst b/docs/topics/dynamic-content.rst index 495111b56..aa32c8943 100644 --- a/docs/topics/dynamic-content.rst +++ b/docs/topics/dynamic-content.rst @@ -62,9 +62,9 @@ download the webpage with an HTTP client like curl_ or wget_ and see if the information can be found in the response they get. If they get a response with the desired data, modify your Scrapy -:class:`~scrapy.http.Request` to match that of the other HTTP client. For +:class:`~scrapy.Request` to match that of the other HTTP client. For example, try using the same user-agent string (:setting:`USER_AGENT`) or the -same :attr:`~scrapy.http.Request.headers`. +same :attr:`~scrapy.Request.headers`. If they also get a response without the desired data, you’ll need to take steps to make your request more similar to that of the web browser. See @@ -81,14 +81,14 @@ Use the :ref:`network tool ` of your web browser to see how your web browser performs the desired request, and try to reproduce that request with Scrapy. -It might be enough to yield a :class:`~scrapy.http.Request` with the same HTTP +It might be enough to yield a :class:`~scrapy.Request` with the same HTTP method and URL. However, you may also need to reproduce the body, headers and -form parameters (see :class:`~scrapy.http.FormRequest`) of that request. +form parameters (see :class:`~scrapy.FormRequest`) of that request. As all major browsers allow to export the requests in `cURL `_ format, Scrapy incorporates the method -:meth:`~scrapy.http.Request.from_curl()` to generate an equivalent -:class:`~scrapy.http.Request` from a cURL command. To get more information +:meth:`~scrapy.Request.from_curl()` to generate an equivalent +:class:`~scrapy.Request` from a cURL command. To get more information visit :ref:`request from curl ` inside the network tool section. @@ -125,7 +125,7 @@ data from it depends on the type of response: If the desired data is inside HTML or XML code embedded within JSON data, you can load that HTML or XML code into a - :class:`~scrapy.selector.Selector` and then + :class:`~scrapy.Selector` and then :ref:`use it ` as usual:: selector = Selector(data['html']) diff --git a/docs/topics/exporters.rst b/docs/topics/exporters.rst index 8648daded..8c30122b6 100644 --- a/docs/topics/exporters.rst +++ b/docs/topics/exporters.rst @@ -90,7 +90,7 @@ described next. 1. Declaring a serializer in the field -------------------------------------- -If you use :class:`~.Item` you can declare a serializer in the +If you use :class:`~scrapy.Item` you can declare a serializer in the :ref:`field metadata `. The serializer must be a callable which receives a value and returns its serialized form. @@ -172,7 +172,7 @@ BaseItemExporter :param field: the field being serialized. If the source :ref:`item object ` does not define field metadata, *field* is an empty :class:`dict`. - :type field: :class:`~scrapy.item.Field` object or a :class:`dict` instance + :type field: :class:`~scrapy.Field` object or a :class:`dict` instance :param name: the name of the field being serialized :type name: str diff --git a/docs/topics/feed-exports.rst b/docs/topics/feed-exports.rst index af7fce852..216a8bc52 100644 --- a/docs/topics/feed-exports.rst +++ b/docs/topics/feed-exports.rst @@ -674,9 +674,9 @@ The function signature should be as follows: :type params: dict :param spider: source spider of the feed items - :type spider: scrapy.spiders.Spider + :type spider: scrapy.Spider -For example, to include the :attr:`name ` of the +For example, to include the :attr:`name ` of the source spider in the feed URI: #. Define the following function somewhere in your project:: diff --git a/docs/topics/item-pipeline.rst b/docs/topics/item-pipeline.rst index 6287ee0ad..5351a2293 100644 --- a/docs/topics/item-pipeline.rst +++ b/docs/topics/item-pipeline.rst @@ -42,7 +42,7 @@ Each item pipeline component is a Python class that must implement the following :type item: :ref:`item object ` :param spider: the spider which scraped the item - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object Additionally, they may also implement the following methods: @@ -51,14 +51,14 @@ Additionally, they may also implement the following methods: This method is called when the spider is opened. :param spider: the spider which was opened - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. method:: close_spider(self, spider) This method is called when the spider is closed. :param spider: the spider which was closed - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. method:: from_crawler(cls, crawler) diff --git a/docs/topics/items.rst b/docs/topics/items.rst index 65bf156ac..7cd482d07 100644 --- a/docs/topics/items.rst +++ b/docs/topics/items.rst @@ -42,7 +42,8 @@ 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:: scrapy.item.Item([arg]) +.. class:: scrapy.Item([arg]) :class:`Item` objects replicate the standard :class:`dict` API, including its ``__init__`` method. @@ -199,7 +200,8 @@ 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. -.. class:: Field([arg]) +.. class:: scrapy.item.Field([arg]) +.. class:: scrapy.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, @@ -317,11 +319,11 @@ If that is not the desired behavior, use a deep copy instead. See :mod:`copy` for more information. To create a shallow copy of an item, you can either call -:meth:`~scrapy.item.Item.copy` on an existing item +:meth:`~scrapy.Item.copy` on an existing item (``product2 = product.copy()``) or instantiate your item class from an existing item (``product2 = Product(product)``). -To create a deep copy, call :meth:`~scrapy.item.Item.deepcopy` instead +To create a deep copy, call :meth:`~scrapy.Item.deepcopy` instead (``product2 = product.deepcopy()``). diff --git a/docs/topics/jobs.rst b/docs/topics/jobs.rst index d855d0133..e49f37a2f 100644 --- a/docs/topics/jobs.rst +++ b/docs/topics/jobs.rst @@ -74,10 +74,10 @@ on cookies. Request serialization --------------------- -For persistence to work, :class:`~scrapy.http.Request` objects must be +For persistence to work, :class:`~scrapy.Request` objects must be serializable with :mod:`pickle`, except for the ``callback`` and ``errback`` values passed to their ``__init__`` method, which must be methods of the -running :class:`~scrapy.spiders.Spider` class. +running :class:`~scrapy.Spider` class. If you wish to log the requests that couldn't be serialized, you can set the :setting:`SCHEDULER_DEBUG` setting to ``True`` in the project's settings page. diff --git a/docs/topics/leaks.rst b/docs/topics/leaks.rst index b895b95cb..477652704 100644 --- a/docs/topics/leaks.rst +++ b/docs/topics/leaks.rst @@ -27,7 +27,7 @@ Common causes of memory leaks It happens quite often (sometimes by accident, sometimes on purpose) that the Scrapy developer passes objects referenced in Requests (for example, using the -:attr:`~scrapy.http.Request.cb_kwargs` or :attr:`~scrapy.http.Request.meta` +:attr:`~scrapy.Request.cb_kwargs` or :attr:`~scrapy.Request.meta` attributes or the request callback function) and that effectively bounds the lifetime of those referenced objects to the lifetime of the Request. This is, by far, the most common cause of memory leaks in Scrapy projects, and a quite @@ -48,9 +48,9 @@ Too Many Requests? ------------------ By default Scrapy keeps the request queue in memory; it includes -:class:`~scrapy.http.Request` objects and all objects -referenced in Request attributes (e.g. in :attr:`~scrapy.http.Request.cb_kwargs` -and :attr:`~scrapy.http.Request.meta`). +:class:`~scrapy.Request` objects and all objects +referenced in Request attributes (e.g. in :attr:`~scrapy.Request.cb_kwargs` +and :attr:`~scrapy.Request.meta`). While not necessarily a leak, this can take a lot of memory. Enabling :ref:`persistent job queue ` could help keeping memory usage in control. @@ -90,11 +90,11 @@ Which objects are tracked? The objects tracked by ``trackrefs`` are all from these classes (and all its subclasses): -* :class:`scrapy.http.Request` +* :class:`scrapy.Request` * :class:`scrapy.http.Response` -* :class:`scrapy.item.Item` -* :class:`scrapy.selector.Selector` -* :class:`scrapy.spiders.Spider` +* :class:`scrapy.Item` +* :class:`scrapy.Selector` +* :class:`scrapy.Spider` A real example -------------- diff --git a/docs/topics/logging.rst b/docs/topics/logging.rst index 00806392a..dda04dc4d 100644 --- a/docs/topics/logging.rst +++ b/docs/topics/logging.rst @@ -93,7 +93,7 @@ path:: Logging from Spiders ==================== -Scrapy provides a :data:`~scrapy.spiders.Spider.logger` within each Spider +Scrapy provides a :data:`~scrapy.Spider.logger` within each Spider instance, which can be accessed and used like this:: import scrapy diff --git a/docs/topics/media-pipeline.rst b/docs/topics/media-pipeline.rst index 156897274..3438cb637 100644 --- a/docs/topics/media-pipeline.rst +++ b/docs/topics/media-pipeline.rst @@ -259,7 +259,7 @@ respectively), the pipeline will put the results under the respective field When using :ref:`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:: +``images`` field. For instance, using the :class:`~scrapy.Item` class:: import scrapy @@ -424,7 +424,7 @@ See here the methods that you can override in your custom Files Pipeline: In addition to ``response``, this method receives the original :class:`request `, :class:`info ` and - :class:`item ` + :class:`item ` You can override this method to customize the download path of each file. @@ -563,7 +563,7 @@ See here the methods that you can override in your custom Images Pipeline: In addition to ``response``, this method receives the original :class:`request `, :class:`info ` and - :class:`item ` + :class:`item ` You can override this method to customize the download path of each file. diff --git a/docs/topics/request-response.rst b/docs/topics/request-response.rst index 73b5a858f..a6a3daf31 100644 --- a/docs/topics/request-response.rst +++ b/docs/topics/request-response.rst @@ -35,7 +35,7 @@ Request objects request (once it's downloaded) as its first parameter. For more information see :ref:`topics-request-response-ref-request-callback-arguments` below. If a Request doesn't specify a callback, the spider's - :meth:`~scrapy.spiders.Spider.parse` method will be used. + :meth:`~scrapy.Spider.parse` method will be used. Note that if exceptions are raised during processing, errback is called instead. :type callback: collections.abc.Callable @@ -60,7 +60,7 @@ Request objects .. caution:: Cookies set via the ``Cookie`` header are not considered by the :ref:`cookies-mw`. If you need to set cookies for a request, use the - :class:`Request.cookies ` parameter. This is a known + :class:`Request.cookies ` parameter. This is a known current limitation that is being worked on. :type headers: dict @@ -92,7 +92,7 @@ Request objects To create a request that does not send stored cookies and does not store received cookies, set the ``dont_merge_cookies`` key to ``True`` - in :attr:`request.meta `. + in :attr:`request.meta `. Example of a request that sends manually-defined cookies and ignores cookie storage:: @@ -107,7 +107,7 @@ Request objects .. caution:: Cookies set via the ``Cookie`` header are not considered by the :ref:`cookies-mw`. If you need to set cookies for a request, use the - :class:`Request.cookies ` parameter. This is a known + :class:`Request.cookies ` parameter. This is a known current limitation that is being worked on. :type cookies: dict or list @@ -495,7 +495,9 @@ fields with form data from :class:`Response` objects. .. _lxml.html forms: https://lxml.de/lxmlhtml.html#forms -.. class:: FormRequest(url, [formdata, ...]) +.. class:: scrapy.http.request.form.FormRequest +.. class:: scrapy.http.FormRequest +.. class:: scrapy.FormRequest(url, [formdata, ...]) The :class:`FormRequest` class adds a new keyword parameter to the ``__init__`` method. The remaining arguments are the same as for the :class:`Request` class and are @@ -694,7 +696,7 @@ Response objects :param request: the initial value of the :attr:`Response.request` attribute. This represents the :class:`Request` that generated this response. - :type request: scrapy.http.Request + :type request: scrapy.Request :param certificate: an object representing the server's SSL certificate. :type certificate: twisted.internet.ssl.Certificate @@ -920,7 +922,7 @@ TextResponse objects .. attribute:: TextResponse.selector - A :class:`~scrapy.selector.Selector` instance using the response as + A :class:`~scrapy.Selector` instance using the response as target. The selector is lazily instantiated on first access. :class:`TextResponse` objects support the following methods in addition to diff --git a/docs/topics/selectors.rst b/docs/topics/selectors.rst index 9caba5ee5..574d4568c 100644 --- a/docs/topics/selectors.rst +++ b/docs/topics/selectors.rst @@ -48,7 +48,7 @@ Constructing selectors .. highlight:: python -Response objects expose a :class:`~scrapy.selector.Selector` instance +Response objects expose a :class:`~scrapy.Selector` instance on ``.selector`` attribute: >>> response.selector.xpath('//span/text()').get() @@ -62,7 +62,7 @@ more shortcuts: ``response.xpath()`` and ``response.css()``: >>> response.css('span::text').get() 'good' -Scrapy selectors are instances of :class:`~scrapy.selector.Selector` class +Scrapy selectors are instances of :class:`~scrapy.Selector` class constructed by passing either :class:`~scrapy.http.TextResponse` object or markup as a string (in ``text`` argument). @@ -175,7 +175,7 @@ of ``None``: 'not-found' Instead of using e.g. ``'@src'`` XPath it is possible to query for attributes -using ``.attrib`` property of a :class:`~scrapy.selector.Selector`: +using ``.attrib`` property of a :class:`~scrapy.Selector`: >>> [img.attrib['src'] for img in response.css('img')] ['image1_thumb.jpg', @@ -383,7 +383,7 @@ ID, or when selecting an unique element on a page): Using selectors with regular expressions ---------------------------------------- -:class:`~scrapy.selector.Selector` also has a ``.re()`` method for extracting +:class:`~scrapy.Selector` also has a ``.re()`` method for extracting data using regular expressions. However, unlike using ``.xpath()`` or ``.css()`` methods, ``.re()`` returns a list of strings. So you can't construct nested ``.re()`` calls. diff --git a/docs/topics/settings.rst b/docs/topics/settings.rst index 0b290598f..1290b4a5e 100644 --- a/docs/topics/settings.rst +++ b/docs/topics/settings.rst @@ -67,7 +67,7 @@ Example:: Spiders (See the :ref:`topics-spiders` chapter for reference) can define their own settings that will take precedence and override the project ones. They can -do so by setting their :attr:`~scrapy.spiders.Spider.custom_settings` attribute:: +do so by setting their :attr:`~scrapy.Spider.custom_settings` attribute:: class MySpider(scrapy.Spider): name = 'myspider' @@ -142,7 +142,7 @@ In a spider, the settings are available through ``self.settings``:: The ``settings`` attribute is set in the base Spider class after the spider is initialized. If you want to use the settings before the initialization (e.g., in your spider's ``__init__()`` method), you'll need to override the - :meth:`~scrapy.spiders.Spider.from_crawler` method. + :meth:`~scrapy.Spider.from_crawler` method. Settings can be accessed through the :attr:`scrapy.crawler.Crawler.settings` attribute of the Crawler that is passed to ``from_crawler`` method in @@ -338,7 +338,7 @@ is non-zero, download delay is enforced per IP, not per domain. DEFAULT_ITEM_CLASS ------------------ -Default: ``'scrapy.item.Item'`` +Default: ``'scrapy.Item'`` The default class that will be used for instantiating items in the :ref:`the Scrapy shell `. @@ -360,7 +360,7 @@ The default headers used for Scrapy HTTP Requests. They're populated in the .. caution:: Cookies set via the ``Cookie`` header are not considered by the :ref:`cookies-mw`. If you need to set cookies for a request, use the - :class:`Request.cookies ` parameter. This is a known + :class:`Request.cookies ` parameter. This is a known current limitation that is being worked on. .. setting:: DEPTH_LIMIT @@ -384,8 +384,8 @@ Default: ``0`` Scope: ``scrapy.spidermiddlewares.depth.DepthMiddleware`` -An integer that is used to adjust the :attr:`~scrapy.http.Request.priority` of -a :class:`~scrapy.http.Request` based on its depth. +An integer that is used to adjust the :attr:`~scrapy.Request.priority` of +a :class:`~scrapy.Request` based on its depth. The priority of a request is adjusted as follows:: @@ -816,14 +816,14 @@ The default (``RFPDupeFilter``) filters based on request fingerprint using the ``scrapy.utils.request.request_fingerprint`` function. In order to change the way duplicates are checked you could subclass ``RFPDupeFilter`` and override its ``request_fingerprint`` method. This method should accept -scrapy :class:`~scrapy.http.Request` object and return its fingerprint +scrapy :class:`~scrapy.Request` object and return its fingerprint (a string). You can disable filtering of duplicate requests by setting :setting:`DUPEFILTER_CLASS` to ``'scrapy.dupefilters.BaseDupeFilter'``. Be very careful about this however, because you can get into crawling loops. It's usually a better idea to set the ``dont_filter`` parameter to -``True`` on the specific :class:`~scrapy.http.Request` that should not be +``True`` on the specific :class:`~scrapy.Request` that should not be filtered. .. setting:: DUPEFILTER_DEBUG diff --git a/docs/topics/shell.rst b/docs/topics/shell.rst index b910fc453..8c90a506c 100644 --- a/docs/topics/shell.rst +++ b/docs/topics/shell.rst @@ -118,7 +118,7 @@ Available Scrapy objects The Scrapy shell automatically creates some convenient objects from the downloaded page, like the :class:`~scrapy.http.Response` object and the -:class:`~scrapy.selector.Selector` objects (for both HTML and XML +:class:`~scrapy.Selector` objects (for both HTML and XML content). Those objects are: @@ -126,12 +126,12 @@ Those objects are: - ``crawler`` - the current :class:`~scrapy.crawler.Crawler` object. - ``spider`` - the Spider which is known to handle the URL, or a - :class:`~scrapy.spiders.Spider` object if there is no spider found for the + :class:`~scrapy.Spider` object if there is no spider found for the current URL -- ``request`` - a :class:`~scrapy.http.Request` object of the last fetched +- ``request`` - a :class:`~scrapy.Request` object of the last fetched page. You can modify this request using - :meth:`~scrapy.http.Request.replace` or fetch a new request (without + :meth:`~scrapy.Request.replace` or fetch a new request (without leaving the shell) using the ``fetch`` shortcut. - ``response`` - a :class:`~scrapy.http.Response` object containing the last diff --git a/docs/topics/signals.rst b/docs/topics/signals.rst index 530af1e37..a67cc1879 100644 --- a/docs/topics/signals.rst +++ b/docs/topics/signals.rst @@ -155,7 +155,7 @@ item_scraped :type item: :ref:`item object ` :param spider: the spider which scraped the item - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object :param response: the response from where the item was scraped :type response: :class:`~scrapy.http.Response` object @@ -175,7 +175,7 @@ item_dropped :type item: :ref:`item object ` :param spider: the spider which scraped the item - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object :param response: the response from where the item was dropped :type response: :class:`~scrapy.http.Response` object @@ -203,7 +203,7 @@ item_error :type response: :class:`~scrapy.http.Response` object :param spider: the spider which raised the exception - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object :param failure: the exception raised :type failure: twisted.python.failure.Failure @@ -223,7 +223,7 @@ spider_closed This signal supports returning deferreds from its handlers. :param spider: the spider which has been closed - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object :param reason: a string which describes the reason why the spider was closed. If it was closed because the spider has completed scraping, the reason @@ -247,7 +247,7 @@ spider_opened This signal supports returning deferreds from its handlers. :param spider: the spider which has been opened - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object spider_idle ~~~~~~~~~~~ @@ -278,7 +278,7 @@ spider_idle This signal does not support returning deferreds from its handlers. :param spider: the spider which has gone idle - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. note:: Scheduling some requests in your :signal:`spider_idle` handler does **not** guarantee that it can prevent the spider from being closed, @@ -303,7 +303,7 @@ spider_error :type response: :class:`~scrapy.http.Response` object :param spider: the spider which raised the exception - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object Request signals --------------- @@ -314,16 +314,16 @@ request_scheduled .. signal:: request_scheduled .. function:: request_scheduled(request, spider) - Sent when the engine schedules a :class:`~scrapy.http.Request`, to be + Sent when the engine schedules a :class:`~scrapy.Request`, to be downloaded later. This signal does not support returning deferreds from its handlers. :param request: the request that reached the scheduler - :type request: :class:`~scrapy.http.Request` object + :type request: :class:`~scrapy.Request` object :param spider: the spider that yielded the request - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object request_dropped ~~~~~~~~~~~~~~~ @@ -331,16 +331,16 @@ request_dropped .. signal:: request_dropped .. function:: request_dropped(request, spider) - Sent when a :class:`~scrapy.http.Request`, scheduled by the engine to be + Sent when a :class:`~scrapy.Request`, scheduled by the engine to be downloaded later, is rejected by the scheduler. This signal does not support returning deferreds from its handlers. :param request: the request that reached the scheduler - :type request: :class:`~scrapy.http.Request` object + :type request: :class:`~scrapy.Request` object :param spider: the spider that yielded the request - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object request_reached_downloader ~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -348,15 +348,15 @@ request_reached_downloader .. signal:: request_reached_downloader .. function:: request_reached_downloader(request, spider) - Sent when a :class:`~scrapy.http.Request` reached downloader. + Sent when a :class:`~scrapy.Request` reached downloader. This signal does not support returning deferreds from its handlers. :param request: the request that reached downloader - :type request: :class:`~scrapy.http.Request` object + :type request: :class:`~scrapy.Request` object :param spider: the spider that yielded the request - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object request_left_downloader ~~~~~~~~~~~~~~~~~~~~~~~ @@ -366,16 +366,16 @@ request_left_downloader .. versionadded:: 2.0 - Sent when a :class:`~scrapy.http.Request` leaves the downloader, even in case of + Sent when a :class:`~scrapy.Request` leaves the downloader, even in case of failure. This signal does not support returning deferreds from its handlers. :param request: the request that reached the downloader - :type request: :class:`~scrapy.http.Request` object + :type request: :class:`~scrapy.Request` object :param spider: the spider that yielded the request - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object bytes_received ~~~~~~~~~~~~~~ @@ -402,10 +402,10 @@ bytes_received :type data: :class:`bytes` object :param request: the request that generated the download - :type request: :class:`~scrapy.http.Request` object + :type request: :class:`~scrapy.Request` object :param spider: the spider associated with the response - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object headers_received ~~~~~~~~~~~~~~~~ @@ -432,10 +432,10 @@ headers_received :type body_length: `int` :param request: the request that generated the download - :type request: :class:`~scrapy.http.Request` object + :type request: :class:`~scrapy.Request` object :param spider: the spider associated with the response - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object Response signals ---------------- @@ -455,10 +455,10 @@ response_received :type response: :class:`~scrapy.http.Response` object :param request: the request that generated the response - :type request: :class:`~scrapy.http.Request` object + :type request: :class:`~scrapy.Request` object :param spider: the spider for which the response is intended - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. note:: The ``request`` argument might not contain the original request that reached the downloader, if a :ref:`topics-downloader-middleware` modifies @@ -479,7 +479,7 @@ response_downloaded :type response: :class:`~scrapy.http.Response` object :param request: the request that generated the response - :type request: :class:`~scrapy.http.Request` object + :type request: :class:`~scrapy.Request` object :param spider: the spider for which the response is intended - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object diff --git a/docs/topics/spider-middleware.rst b/docs/topics/spider-middleware.rst index 11bbbb58d..f0158dc41 100644 --- a/docs/topics/spider-middleware.rst +++ b/docs/topics/spider-middleware.rst @@ -93,7 +93,7 @@ object gives you access, for example, to the :ref:`settings `. :type response: :class:`~scrapy.http.Response` object :param spider: the spider for which this response is intended - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. method:: process_spider_output(response, result, spider) @@ -102,7 +102,7 @@ object gives you access, for example, to the :ref:`settings `. it has processed the response. :meth:`process_spider_output` must return an iterable of - :class:`~scrapy.http.Request` objects and :ref:`item object + :class:`~scrapy.Request` objects and :ref:`item object `. :param response: the response which generated this output from the @@ -110,11 +110,11 @@ object gives you access, for example, to the :ref:`settings `. :type response: :class:`~scrapy.http.Response` object :param result: the result returned by the spider - :type result: an iterable of :class:`~scrapy.http.Request` objects and + :type result: an iterable of :class:`~scrapy.Request` objects and :ref:`item object ` :param spider: the spider whose result is being processed - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. method:: process_spider_exception(response, exception, spider) @@ -122,7 +122,7 @@ object gives you access, for example, to the :ref:`settings `. 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` objects and :ref:`item object + iterable of :class:`~scrapy.Request` objects and :ref:`item object `. If it returns ``None``, Scrapy will continue processing this exception, @@ -142,7 +142,7 @@ object gives you access, for example, to the :ref:`settings `. :type exception: :exc:`Exception` object :param spider: the spider which raised the exception - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. method:: process_start_requests(start_requests, spider) @@ -152,7 +152,7 @@ object gives you access, for example, to the :ref:`settings `. items). It receives an iterable (in the ``start_requests`` parameter) and must - return another iterable of :class:`~scrapy.http.Request` objects. + return another iterable of :class:`~scrapy.Request` objects. .. note:: When implementing this method in your spider middleware, you should always return an iterable (that follows the input one) and @@ -164,10 +164,10 @@ object gives you access, for example, to the :ref:`settings `. (like a time limit or item/page count). :param start_requests: the start requests - :type start_requests: an iterable of :class:`~scrapy.http.Request` + :type start_requests: an iterable of :class:`~scrapy.Request` :param spider: the spider to whom the start requests belong - :type spider: :class:`~scrapy.spiders.Spider` object + :type spider: :class:`~scrapy.Spider` object .. method:: from_crawler(cls, crawler) @@ -251,7 +251,7 @@ this:: .. reqmeta:: handle_httpstatus_all The ``handle_httpstatus_list`` key of :attr:`Request.meta -` can also be used to specify which response codes to +` can also be used to specify which response codes to allow on a per-request basis. You can also set the meta key ``handle_httpstatus_all`` to ``True`` if you want to allow any response code for a request, and ``False`` to disable the effects of the ``handle_httpstatus_all`` key. @@ -295,7 +295,7 @@ OffsiteMiddleware Filters out Requests for URLs outside the domains covered by the spider. This middleware filters out every request whose host names aren't in the - spider's :attr:`~scrapy.spiders.Spider.allowed_domains` attribute. + spider's :attr:`~scrapy.Spider.allowed_domains` attribute. All subdomains of any domain in the list are also allowed. E.g. the rule ``www.example.org`` will also allow ``bob.www.example.org`` but not ``www2.example.com`` nor ``example.com``. @@ -313,10 +313,10 @@ OffsiteMiddleware will be printed (but only for the first request filtered). If the spider doesn't define an - :attr:`~scrapy.spiders.Spider.allowed_domains` attribute, or the + :attr:`~scrapy.Spider.allowed_domains` attribute, or the attribute is empty, the offsite middleware will allow all requests. - If the request has the :attr:`~scrapy.http.Request.dont_filter` attribute + If the request has the :attr:`~scrapy.Request.dont_filter` attribute set, the offsite middleware will allow the request even if its domain is not listed in allowed domains. diff --git a/docs/topics/spiders.rst b/docs/topics/spiders.rst index 903fbd383..67b9e2e0e 100644 --- a/docs/topics/spiders.rst +++ b/docs/topics/spiders.rst @@ -17,15 +17,15 @@ For spiders, the scraping cycle goes through something like this: those requests. The first requests to perform are obtained by calling the - :meth:`~scrapy.spiders.Spider.start_requests` method which (by default) - generates :class:`~scrapy.http.Request` for the URLs specified in the - :attr:`~scrapy.spiders.Spider.start_urls` and the - :attr:`~scrapy.spiders.Spider.parse` method as callback function for the + :meth:`~scrapy.Spider.start_requests` method which (by default) + generates :class:`~scrapy.Request` for the URLs specified in the + :attr:`~scrapy.Spider.start_urls` and the + :attr:`~scrapy.Spider.parse` method as callback function for the Requests. 2. In the callback function, you parse the response (web page) and return :ref:`item objects `, - :class:`~scrapy.http.Request` objects, or an iterable of these objects. + :class:`~scrapy.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 response handled by the specified callback. @@ -50,7 +50,8 @@ We will talk about those types here. scrapy.Spider ============= -.. class:: Spider() +.. class:: scrapy.spiders.Spider() +.. class:: scrapy.Spider() This is the simplest spider, and the one from which every other spider must inherit (including spiders that come bundled with Scrapy, as well as spiders @@ -86,7 +87,7 @@ scrapy.Spider A list of URLs where the spider will begin to crawl from, when no particular URLs are specified. So, the first pages downloaded will be those - listed here. The subsequent :class:`~scrapy.http.Request` will be generated successively from data + listed here. The subsequent :class:`~scrapy.Request` will be generated successively from data contained in the start URLs. .. attribute:: custom_settings @@ -179,7 +180,7 @@ 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 :ref:`item objects + iterable of :class:`~scrapy.Request` and/or :ref:`item objects `. :param response: the response to parse @@ -234,7 +235,7 @@ 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 :class:`~scrapy.item.Item` objects:: +to give data more structure you can use :class:`~scrapy.Item` objects:: import scrapy from myproject.items import MyItem @@ -373,7 +374,7 @@ CrawlSpider This method is called for each response produced for the URLs in the spider's ``start_urls`` attribute. It allows to parse the initial responses and must return either an - :ref:`item object `, a :class:`~scrapy.http.Request` + :ref:`item object `, a :class:`~scrapy.Request` object, or an iterable containing any of them. Crawling rules @@ -383,7 +384,7 @@ Crawling rules ``link_extractor`` is a :ref:`Link Extractor ` object which defines how links will be extracted from each crawled page. Each produced link will - be used to generate a :class:`~scrapy.http.Request` object, which will contain the + be used to generate a :class:`~scrapy.Request` object, which will contain the link's text in its ``meta`` dictionary (under the ``link_text`` key). If omitted, a default link extractor created with no arguments will be used, resulting in all links being extracted. @@ -392,9 +393,9 @@ 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 - :ref:`item objects ` and/or :class:`~scrapy.http.Request` objects + :ref:`item objects ` and/or :class:`~scrapy.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` + object will contain the text of the link that produced the :class:`~scrapy.Request` in its ``meta`` dictionary (under the ``link_text`` key) ``cb_kwargs`` is a dict containing the keyword arguments to be passed to the @@ -411,7 +412,7 @@ Crawling rules ``process_request`` is a callable (or a string, in which case a method from the spider object with that name will be used) which will be called for every - :class:`~scrapy.http.Request` extracted by this rule. This callable should + :class:`~scrapy.Request` extracted by this rule. This callable should take said request as first argument and the :class:`~scrapy.http.Response` from which the request originated as second argument. It must return a ``Request`` object or ``None`` (to filter out the request). @@ -470,7 +471,7 @@ Let's now take a look at an example CrawlSpider with rules:: This spider would start crawling example.com's home page, collecting category links, and item links, parsing the latter with the ``parse_item`` method. For each item response, some data will be extracted from the HTML using XPath, and -an :class:`~scrapy.item.Item` will be filled with it. +an :class:`~scrapy.Item` will be filled with it. XMLFeedSpider ------------- @@ -493,11 +494,11 @@ XMLFeedSpider - ``'iternodes'`` - a fast iterator based on regular expressions - - ``'html'`` - an iterator which uses :class:`~scrapy.selector.Selector`. + - ``'html'`` - an iterator which uses :class:`~scrapy.Selector`. Keep in mind this uses DOM parsing and must load all DOM in memory which could be a problem for big feeds - - ``'xml'`` - an iterator which uses :class:`~scrapy.selector.Selector`. + - ``'xml'`` - an iterator which uses :class:`~scrapy.Selector`. Keep in mind this uses DOM parsing and must load all DOM in memory which could be a problem for big feeds @@ -515,7 +516,7 @@ XMLFeedSpider available in that document that will be processed with this spider. The ``prefix`` and ``uri`` will be used to automatically register namespaces using the - :meth:`~scrapy.selector.Selector.register_namespace` method. + :meth:`~scrapy.Selector.register_namespace` method. You can then specify nodes with namespaces in the :attr:`itertag` attribute. @@ -542,10 +543,10 @@ XMLFeedSpider This method is called for the nodes matching the provided tag name (``itertag``). Receives the response and an - :class:`~scrapy.selector.Selector` for each node. Overriding this + :class:`~scrapy.Selector` for each node. Overriding this method is mandatory. Otherwise, you spider won't work. This method must return an :ref:`item object `, a - :class:`~scrapy.http.Request` object, or an iterable containing any of + :class:`~scrapy.Request` object, or an iterable containing any of them. .. method:: process_results(response, results) @@ -587,7 +588,7 @@ These spiders are pretty easy to use, let's have a look at one example:: Basically what we did up there was to create a spider that downloads a feed from the given ``start_urls``, and then iterates through each of its ``item`` tags, -prints them out, and stores some random data in an :class:`~scrapy.item.Item`. +prints them out, and stores some random data in an :class:`~scrapy.Item`. CSVFeedSpider -------------