.. _topics-settings:
========
Settings
========
The Scrapy settings allows you to customize the behaviour of all Scrapy
components, including the core, extensions, pipelines and spiders themselves.
The infrastructure of the settings provides a global namespace of key-value mappings
that the code can use to pull configuration values from. The settings can be
populated through different mechanisms, which are described below.
The settings are also the mechanism for selecting the currently active Scrapy
project (in case you have many).
For a list of available built-in settings see: :ref:`topics-settings-ref`.
.. _topics-settings-module-envvar:
Designating the settings
========================
When you use Scrapy, you have to tell it which settings you're using. You can
do this by using an environment variable, ``SCRAPY_SETTINGS_MODULE``.
The value of ``SCRAPY_SETTINGS_MODULE`` should be in Python path syntax, e.g.
``myproject.settings``. Note that the settings module should be on the
Python `import search path`_.
.. _import search path: https://docs.python.org/2/tutorial/modules.html#the-module-search-path
.. _populating-settings:
Populating the settings
=======================
Settings can be populated using different mechanisms, each of which having a
different precedence. Here is the list of them in decreasing order of
precedence:
1. Command line options (most precedence)
2. Settings per-spider
3. Project settings module
4. Default settings per-command
5. Default global settings (less precedence)
The population of these settings sources is taken care of internally, but a
manual handling is possible using API calls. See the
:ref:`topics-api-settings` topic for reference.
These mechanisms are described in more detail below.
1. Command line options
-----------------------
Arguments provided by the command line are the ones that take most precedence,
overriding any other options. You can explicitly override one (or more)
settings using the ``-s`` (or ``--set``) command line option.
.. highlight:: sh
Example::
scrapy crawl myspider -s LOG_FILE=scrapy.log
2. Settings per-spider
----------------------
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::
class MySpider(scrapy.Spider):
name = 'myspider'
custom_settings = {
'SOME_SETTING': 'some value',
}
3. Project settings module
--------------------------
The project settings module is the standard configuration file for your Scrapy
project, it's where most of your custom settings will be populated. For a
standard Scrapy project, this means you'll be adding or changing the settings
in the ``settings.py`` file created for your project.
4. Default settings per-command
-------------------------------
Each :doc:`Scrapy tool </topics/commands>` command can have its own default
settings, which override the global default settings. Those custom command
settings are specified in the ``default_settings`` attribute of the command
class.
5. Default global settings
--------------------------
The global defaults are located in the ``scrapy.settings.default_settings``
module and documented in the :ref:`topics-settings-ref` section.
How to access settings
======================
.. highlight:: python
In a spider, the settings are available through ``self.settings``::
class MySpider(scrapy.Spider):
name = 'myspider'
start_urls = ['http://example.com']
def parse(self, response):
print("Existing settings: %s" % self.settings.attributes.keys())
.. note::
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.
Settings can be accessed through the :attr:`scrapy.crawler.Crawler.settings`
attribute of the Crawler that is passed to ``from_crawler`` method in
extensions, middlewares and item pipelines::
class MyExtension(object):
def __init__(self, log_is_enabled=False):
if log_is_enabled:
print("log is enabled!")
@classmethod
def from_crawler(cls, crawler):
settings = crawler.settings
return cls(settings.getbool('LOG_ENABLED'))
The settings object can be used like a dict (e.g.,
``settings['LOG_ENABLED']``), but it's usually preferred to extract the setting
in the format you need it to avoid type errors, using one of the methods
provided by the :class:`~scrapy.settings.Settings` API.
Rationale for setting names
===========================
Setting names are usually prefixed with the component that they configure. For
example, proper setting names for a fictional robots.txt extension would be
``ROBOTSTXT_ENABLED``, ``ROBOTSTXT_OBEY``, ``ROBOTSTXT_CACHEDIR``, etc.
.. _topics-settings-ref:
Built-in settings reference
===========================
Here's a list of all available Scrapy settings, in alphabetical order, along
with their default values and the scope where they apply.
The scope, where available, shows where the setting is being used, if it's tied
to any particular component. In that case the module of that component will be
shown, typically an extension, middleware or pipeline. It also means that the
component must be enabled in order for the setting to have any effect.
.. setting:: ASYNCIO_REACTOR
ASYNCIO_REACTOR
---------------
Default: ``False``
Whether to install and require the Twisted reactor that uses the asyncio loop.
When this option is set to ``True``, Scrapy will require
:class:`~twisted.internet.asyncioreactor.AsyncioSelectorReactor`. It will
install this reactor if no reactor is installed yet, such as when using the
``scrapy`` script or :class:`~scrapy.crawler.CrawlerProcess`. If you are using
:class:`~scrapy.crawler.CrawlerRunner`, you need to install the correct reactor
manually. If a different reactor is installed outside Scrapy, it will raise an
exception.
The default value for this option is currently ``False`` to maintain backward
compatibility and avoid possible problems caused by using a different Twisted
reactor.
.. setting:: AWS_ACCESS_KEY_ID
AWS_ACCESS_KEY_ID
-----------------
Default: ``None``
The AWS access key used by code that requires access to `Amazon Web services`_,
such as the :ref:`S3 feed storage backend <topics-feed-storage-s3>`.
.. setting:: AWS_SECRET_ACCESS_KEY
AWS_SECRET_ACCESS_KEY
---------------------
Default: ``None``
The AWS secret key used by code that requires access to `Amazon Web services`_,
such as the :ref:`S3 feed storage backend <topics-feed-storage-s3>`.
.. setting:: AWS_ENDPOINT_URL
AWS_ENDPOINT_URL
----------------
Default: ``None``
Endpoint URL used for S3-like storage, for example Minio or s3.scality.
.. setting:: AWS_USE_SSL
AWS_USE_SSL
-----------
Default: ``None``
Use this option if you want to disable SSL connection for communication with
S3 or S3-like storage. By default SSL will be used.
.. setting:: AWS_VERIFY
AWS_VERIFY
----------
Default: ``None``
Verify SSL connection between Scrapy and S3 or S3-like storage. By default
SSL verification will occur.
.. setting:: AWS_REGION_NAME
AWS_REGION_NAME
---------------
Default: ``None``
The name of the region associated with the AWS client.
.. setting:: BOT_NAME
BOT_NAME
--------
Default: ``'scrapybot'``
The name of the bot implemented by this Scrapy project (also known as the
project name). This name will be used for the logging too.
It's automatically populated with your project name when you create your
project with the :command:`startproject` command.
.. setting:: CONCURRENT_ITEMS
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>`).
.. setting:: CONCURRENT_REQUESTS
CONCURRENT_REQUESTS
-------------------
Default: ``16``
The maximum number of concurrent (ie. simultaneous) requests that will be
performed by the Scrapy downloader.
.. setting:: CONCURRENT_REQUESTS_PER_DOMAIN
CONCURRENT_REQUESTS_PER_DOMAIN
------------------------------
Default: ``8``
The maximum number of concurrent (ie. simultaneous) requests that will be
performed to any single domain.
See also: :ref:`topics-autothrottle` and its
:setting:`AUTOTHROTTLE_TARGET_CONCURRENCY` option.
.. setting:: CONCURRENT_REQUESTS_PER_IP
CONCURRENT_REQUESTS_PER_IP
--------------------------
Default: ``0``
The maximum number of concurrent (ie. simultaneous) requests that will be
performed to any single IP. If non-zero, the
:setting:`CONCURRENT_REQUESTS_PER_DOMAIN` setting is ignored, and this one is
used instead. In other words, concurrency limits will be applied per IP, not
per domain.
This setting also affects :setting:`DOWNLOAD_DELAY` and
:ref:`topics-autothrottle`: if :setting:`CONCURRENT_REQUESTS_PER_IP`
is non-zero, download delay is enforced per IP, not per domain.
.. setting:: DEFAULT_ITEM_CLASS
DEFAULT_ITEM_CLASS
------------------
Default: ``'scrapy.item.Item'``
The default class that will be used for instantiating items in the :ref:`the
Scrapy shell <topics-shell>`.
.. setting:: DEFAULT_REQUEST_HEADERS
DEFAULT_REQUEST_HEADERS
-----------------------
Default::
{
'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
'Accept-Language': 'en',
}
The default headers used for Scrapy HTTP Requests. They're populated in the
:class:`~scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware`.
.. setting:: DEPTH_LIMIT
DEPTH_LIMIT
-----------
Default: ``0``
Scope: ``scrapy.spidermiddlewares.depth.DepthMiddleware``
The maximum depth that will be allowed to crawl for any site. If zero, no limit
will be imposed.
.. setting:: DEPTH_PRIORITY
DEPTH_PRIORITY
--------------
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.
The priority of a request is adjusted as follows::
request.priority = request.priority - ( depth * DEPTH_PRIORITY )
As depth increases, positive values of ``DEPTH_PRIORITY`` decrease request
priority (BFO), while negative values increase request priority (DFO). See
also :ref:`faq-bfo-dfo`.
.. note::
This setting adjusts priority **in the opposite way** compared to
other priority settings :setting:`REDIRECT_PRIORITY_ADJUST`
and :setting:`RETRY_PRIORITY_ADJUST`.
.. setting:: DEPTH_STATS_VERBOSE
DEPTH_STATS_VERBOSE
-------------------
Default: ``False``
Scope: ``scrapy.spidermiddlewares.depth.DepthMiddleware``
Whether to collect verbose depth stats. If this is enabled, the number of
requests for each depth is collected in the stats.
.. setting:: DNSCACHE_ENABLED
DNSCACHE_ENABLED
----------------
Default: ``True``
Whether to enable DNS in-memory cache.
.. setting:: DNSCACHE_SIZE
DNSCACHE_SIZE
-------------
Default: ``10000``
DNS in-memory cache size.
.. setting:: DNS_TIMEOUT
DNS_TIMEOUT
-----------
Default: ``60``
Timeout for processing of DNS queries in seconds. Float is supported.
.. setting:: DOWNLOADER
DOWNLOADER
----------
Default: ``'scrapy.core.downloader.Downloader'``
The downloader to use for crawling.
.. setting:: DOWNLOADER_HTTPCLIENTFACTORY
DOWNLOADER_HTTPCLIENTFACTORY
----------------------------
Default: ``'scrapy.core.downloader.webclient.ScrapyHTTPClientFactory'``
Defines a Twisted ``protocol.ClientFactory`` class to use for HTTP/1.0
connections (for ``HTTP10DownloadHandler``).
.. note::
HTTP/1.0 is rarely used nowadays so you can safely ignore this setting,
unless you use Twisted<11.1, or if you really want to use HTTP/1.0
and override :setting:`DOWNLOAD_HANDLERS_BASE` for ``http(s)`` scheme
accordingly, i.e. to
``'scrapy.core.downloader.handlers.http.HTTP10DownloadHandler'``.
.. setting:: DOWNLOADER_CLIENTCONTEXTFACTORY
DOWNLOADER_CLIENTCONTEXTFACTORY
-------------------------------
Default: ``'scrapy.core.downloader.contextfactory.ScrapyClientContextFactory'``
Represents the classpath to the ContextFactory to use.
Here, "ContextFactory" is a Twisted term for SSL/TLS contexts, defining
the TLS/SSL protocol version to use, whether to do certificate verification,
or even enable client-side authentication (and various other things).
.. note::
Scrapy default context factory **does NOT perform remote server
certificate verification**. This is usually fine for web scraping.
If you do need remote server certificate verification enabled,
Scrapy also has another context factory class that you can set,
``'scrapy.core.downloader.contextfactory.BrowserLikeContextFactory'``,
which uses the platform's certificates to validate remote endpoints.
**This is only available if you use Twisted>=14.0.**
If you do use a custom ContextFactory, make sure its ``__init__`` method
accepts a ``method`` parameter (this is the ``OpenSSL.SSL`` method mapping
:setting:`DOWNLOADER_CLIENT_TLS_METHOD`), a ``tls_verbose_logging``
parameter (``bool``) and a ``tls_ciphers`` parameter (see
:setting:`DOWNLOADER_CLIENT_TLS_CIPHERS`).
.. setting:: DOWNLOADER_CLIENT_TLS_CIPHERS
DOWNLOADER_CLIENT_TLS_CIPHERS
-----------------------------
Default: ``'DEFAULT'``
Use this setting to customize the TLS/SSL ciphers used by the default
HTTP/1.1 downloader.
The setting should contain a string in the `OpenSSL cipher list format`_,
these ciphers will be used as client ciphers. Changing this setting may be
necessary to access certain HTTPS websites: for example, you may need to use
``'DEFAULT:!DH'`` for a website with weak DH parameters or enable a
specific cipher that is not included in ``DEFAULT`` if a website requires it.
.. _OpenSSL cipher list format: https://www.openssl.org/docs/manmaster/man1/ciphers.html#CIPHER-LIST-FORMAT
.. setting:: DOWNLOADER_CLIENT_TLS_METHOD
DOWNLOADER_CLIENT_TLS_METHOD
----------------------------
Default: ``'TLS'``
Use this setting to customize the TLS/SSL method used by the default
HTTP/1.1 downloader.
This setting must be one of these string values:
- ``'TLS'``: maps to OpenSSL's ``TLS_method()`` (a.k.a ``SSLv23_method()``),
which allows protocol negotiation, starting from the highest supported
by the platform; **default, recommended**
- ``'TLSv1.0'``: this value forces HTTPS connections to use TLS version 1.0 ;
set this if you want the behavior of Scrapy<1.1
- ``'TLSv1.1'``: forces TLS version 1.1
- ``'TLSv1.2'``: forces TLS version 1.2
- ``'SSLv3'``: forces SSL version 3 (**not recommended**)
.. note::
We recommend that you use PyOpenSSL>=0.13 and Twisted>=0.13
or above (Twisted>=14.0 if you can).
.. setting:: DOWNLOADER_CLIENT_TLS_VERBOSE_LOGGING
DOWNLOADER_CLIENT_TLS_VERBOSE_LOGGING
-------------------------------------
Default: ``False``
Setting this to ``True`` will enable DEBUG level messages about TLS connection
parameters after establishing HTTPS connections. The kind of information logged
depends on the versions of OpenSSL and pyOpenSSL.
This setting is only used for the default
:setting:`DOWNLOADER_CLIENTCONTEXTFACTORY`.
.. setting:: DOWNLOADER_MIDDLEWARES
DOWNLOADER_MIDDLEWARES
----------------------
Default:: ``{}``
A dict containing the downloader middlewares enabled in your project, and their
orders. For more info see :ref:`topics-downloader-middleware-setting`.
.. setting:: DOWNLOADER_MIDDLEWARES_BASE
DOWNLOADER_MIDDLEWARES_BASE
---------------------------
Default::
{
'scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware': 100,
'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware': 300,
'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware': 350,
'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware': 400,
'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware': 500,
'scrapy.downloadermiddlewares.retry.RetryMiddleware': 550,
'scrapy.downloadermiddlewares.ajaxcrawl.AjaxCrawlMiddleware': 560,
'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware': 580,
'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware': 590,
'scrapy.downloadermiddlewares.redirect.RedirectMiddleware': 600,
'scrapy.downloadermiddlewares.cookies.CookiesMiddleware': 700,
'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware': 750,
'scrapy.downloadermiddlewares.stats.DownloaderStats': 850,
'scrapy.downloadermiddlewares.httpcache.HttpCacheMiddleware': 900,
}
A dict containing the downloader middlewares enabled by default in Scrapy. Low
orders are closer to the engine, high orders are closer to the downloader. You
should never modify this setting in your project, modify
:setting:`DOWNLOADER_MIDDLEWARES` instead. For more info see
:ref:`topics-downloader-middleware-setting`.
.. setting:: DOWNLOADER_STATS
DOWNLOADER_STATS
----------------
Default: ``True``
Whether to enable downloader stats collection.
.. setting:: DOWNLOAD_DELAY
DOWNLOAD_DELAY
--------------
Default: ``0``
The amount of time (in secs) that the downloader should wait before downloading
consecutive pages from the same website. This can be used to throttle the
crawling speed to avoid hitting servers too hard. Decimal numbers are
supported. Example::
DOWNLOAD_DELAY = 0.25 # 250 ms of delay
This setting is also affected by the :setting:`RANDOMIZE_DOWNLOAD_DELAY`
setting (which is enabled by default). By default, Scrapy doesn't wait a fixed
amount of time between requests, but uses a random interval between 0.5 * :setting:`DOWNLOAD_DELAY` and 1.5 * :setting:`DOWNLOAD_DELAY`.
When :setting:`CONCURRENT_REQUESTS_PER_IP` is non-zero, delays are enforced
per ip address instead of per domain.
.. _spider-download_delay-attribute:
You can also change this setting per spider by setting ``download_delay``
spider attribute.
.. setting:: DOWNLOAD_HANDLERS
DOWNLOAD_HANDLERS
-----------------
Default: ``{}``
A dict containing the request downloader handlers enabled in your project.
See :setting:`DOWNLOAD_HANDLERS_BASE` for example format.
.. setting:: DOWNLOAD_HANDLERS_BASE
DOWNLOAD_HANDLERS_BASE
----------------------
Default::
{
'file': 'scrapy.core.downloader.handlers.file.FileDownloadHandler',
'http': 'scrapy.core.downloader.handlers.http.HTTPDownloadHandler',
'https': 'scrapy.core.downloader.handlers.http.HTTPDownloadHandler',
's3': 'scrapy.core.downloader.handlers.s3.S3DownloadHandler',
'ftp': 'scrapy.core.downloader.handlers.ftp.FTPDownloadHandler',
}
A dict containing the request download handlers enabled by default in Scrapy.
You should never modify this setting in your project, modify
:setting:`DOWNLOAD_HANDLERS` instead.
You can disable any of these download handlers by assigning ``None`` to their
URI scheme in :setting:`DOWNLOAD_HANDLERS`. E.g., to disable the built-in FTP
handler (without replacement), place this in your ``settings.py``::
DOWNLOAD_HANDLERS = {
'ftp': None,
}
.. setting:: DOWNLOAD_TIMEOUT
DOWNLOAD_TIMEOUT
----------------
Default: ``180``
The amount of time (in secs) that the downloader will wait before timing out.
.. note::
This timeout can be set per spider using :attr:`download_timeout`
spider attribute and per-request using :reqmeta:`download_timeout`
Request.meta key.
.. setting:: DOWNLOAD_MAXSIZE
DOWNLOAD_MAXSIZE
----------------
Default: ``1073741824`` (1024MB)
The maximum response size (in bytes) that downloader will download.
If you want to disable it set to 0.
.. reqmeta:: download_maxsize
.. note::
This size can be set per spider using :attr:`download_maxsize`
spider attribute and per-request using :reqmeta:`download_maxsize`
Request.meta key.
This feature needs Twisted >= 11.1.
.. setting:: DOWNLOAD_WARNSIZE
DOWNLOAD_WARNSIZE
-----------------
Default: ``33554432`` (32MB)
The response size (in bytes) that downloader will start to warn.
If you want to disable it set to 0.
.. note::
This size can be set per spider using :attr:`download_warnsize`
spider attribute and per-request using :reqmeta:`download_warnsize`
Request.meta key.
This feature needs Twisted >= 11.1.
.. setting:: DOWNLOAD_FAIL_ON_DATALOSS
DOWNLOAD_FAIL_ON_DATALOSS
-------------------------
Default: ``True``
Whether or not to fail on broken responses, that is, declared
``Content-Length`` does not match content sent by the server or chunked
response was not properly finish. If ``True``, these responses raise a
``ResponseFailed([_DataLoss])`` error. If ``False``, these responses
are passed through and the flag ``dataloss`` is added to the response, i.e.:
``'dataloss' in response.flags`` is ``True``.
Optionally, this can be set per-request basis by using the
:reqmeta:`download_fail_on_dataloss` Request.meta key to ``False``.
.. note::
A broken response, or data loss error, may happen under several
circumstances, from server misconfiguration to network errors to data
corruption. It is up to the user to decide if it makes sense to process
broken responses considering they may contain partial or incomplete content.
If :setting:`RETRY_ENABLED` is ``True`` and this setting is set to ``True``,
the ``ResponseFailed([_DataLoss])`` failure will be retried as usual.
.. setting:: DUPEFILTER_CLASS
DUPEFILTER_CLASS
----------------
Default: ``'scrapy.dupefilters.RFPDupeFilter'``
The class used to detect and filter duplicate requests.
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
(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
filtered.
.. setting:: DUPEFILTER_DEBUG
DUPEFILTER_DEBUG
----------------
Default: ``False``
By default, ``RFPDupeFilter`` only logs the first duplicate request.
Setting :setting:`DUPEFILTER_DEBUG` to ``True`` will make it log all duplicate requests.
.. setting:: EDITOR
EDITOR
------
Default: ``vi`` (on Unix systems) or the IDLE editor (on Windows)
The editor to use for editing spiders with the :command:`edit` command.
Additionally, if the ``EDITOR`` environment variable is set, the :command:`edit`
command will prefer it over the default setting.
.. setting:: EXTENSIONS
EXTENSIONS
----------
Default:: ``{}``
A dict containing the extensions enabled in your project, and their orders.
.. setting:: EXTENSIONS_BASE
EXTENSIONS_BASE
---------------
Default::
{
'scrapy.extensions.corestats.CoreStats': 0,
'scrapy.extensions.telnet.TelnetConsole': 0,
'scrapy.extensions.memusage.MemoryUsage': 0,
'scrapy.extensions.memdebug.MemoryDebugger': 0,
'scrapy.extensions.closespider.CloseSpider': 0,
'scrapy.extensions.feedexport.FeedExporter': 0,
'scrapy.extensions.logstats.LogStats': 0,
'scrapy.extensions.spiderstate.SpiderState': 0,
'scrapy.extensions.throttle.AutoThrottle': 0,
}
A dict containing the extensions available by default in Scrapy, and their
orders. This setting contains all stable built-in extensions. Keep in mind that
some of them need to be enabled through a setting.
For more information See the :ref:`extensions user guide <topics-extensions>`
and the :ref:`list of available extensions <topics-extensions-ref>`.
.. setting:: FEED_TEMPDIR
FEED_TEMPDIR
------------
The Feed Temp dir allows you to set a custom folder to save crawler
temporary files before uploading with :ref:`FTP feed storage <topics-feed-storage-ftp>` and
:ref:`Amazon S3 <topics-feed-storage-s3>`.
.. setting:: FTP_PASSIVE_MODE
FTP_PASSIVE_MODE
----------------
Default: ``True``
Whether or not to use passive mode when initiating FTP transfers.
.. reqmeta:: ftp_password
.. setting:: FTP_PASSWORD
FTP_PASSWORD
------------
Default: ``"guest"``
The password to use for FTP connections when there is no ``"ftp_password"``
in ``Request`` meta.
.. note::
Paraphrasing `RFC 1635`_, although it is common to use either the password
"guest" or one's e-mail address for anonymous FTP,
some FTP servers explicitly ask for the user's e-mail address
and will not allow login with the "guest" password.
.. _RFC 1635: https://tools.ietf.org/html/rfc1635
.. reqmeta:: ftp_user
.. setting:: FTP_USER
FTP_USER
--------
Default: ``"anonymous"``
The username to use for FTP connections when there is no ``"ftp_user"``
in ``Request`` meta.
.. setting:: ITEM_PIPELINES
ITEM_PIPELINES
--------------
Default: ``{}``
A dict containing the item pipelines to use, and their orders. Order values are
arbitrary, but it is customary to define them in the 0-1000 range. Lower orders
process before higher orders.
Example::
ITEM_PIPELINES = {
'mybot.pipelines.validate.ValidateMyItem': 300,
'mybot.pipelines.validate.StoreMyItem': 800,
}
.. setting:: ITEM_PIPELINES_BASE
ITEM_PIPELINES_BASE
-------------------
Default: ``{}``
A dict containing the pipelines enabled by default in Scrapy. You should never
modify this setting in your project, modify :setting:`ITEM_PIPELINES` instead.
.. setting:: LOG_ENABLED
LOG_ENABLED
-----------
Default: ``True``
Whether to enable logging.
.. setting:: LOG_ENCODING
LOG_ENCODING
------------
Default: ``'utf-8'``
The encoding to use for logging.
.. setting:: LOG_FILE
LOG_FILE
--------
Default: ``None``
File name to use for logging output. If ``None``, standard error will be used.
.. setting:: LOG_FORMAT
LOG_FORMAT
----------
Default: ``'%(asctime)s [%(name)s] %(levelname)s: %(message)s'``
String for formatting log messages. Refer to the `Python logging documentation`_ for the whole list of available
placeholders.
.. _Python logging documentation: https://docs.python.org/2/library/logging.html#logrecord-attributes
.. setting:: LOG_DATEFORMAT
LOG_DATEFORMAT
--------------
Default: ``'%Y-%m-%d %H:%M:%S'``
String for formatting date/time, expansion of the ``%(asctime)s`` placeholder
in :setting:`LOG_FORMAT`. Refer to the `Python datetime documentation`_ for the whole list of available
directives.
.. _Python datetime documentation: https://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior
.. setting:: LOG_FORMATTER
LOG_FORMATTER
-------------
Default: :class:`scrapy.logformatter.LogFormatter`
The class to use for :ref:`formatting log messages <custom-log-formats>` for different actions.
.. setting:: LOG_LEVEL
LOG_LEVEL
---------
Default: ``'DEBUG'``
Minimum level to log. Available levels are: CRITICAL, ERROR, WARNING,
INFO, DEBUG. For more info see :ref:`topics-logging`.
.. setting:: LOG_STDOUT
LOG_STDOUT
----------
Default: ``False``
If ``True``, all standard output (and error) of your process will be redirected
to the log. For example if you ``print('hello')`` it will appear in the Scrapy
log.
.. setting:: LOG_SHORT_NAMES
LOG_SHORT_NAMES
---------------
Default: ``False``
If ``True``, the logs will just contain the root path. If it is set to ``False``
then it displays the component responsible for the log output
.. setting:: LOGSTATS_INTERVAL
LOGSTATS_INTERVAL
-----------------
Default: ``60.0``
The interval (in seconds) between each logging printout of the stats
by :class:`~scrapy.extensions.logstats.LogStats`.
.. setting:: MEMDEBUG_ENABLED
MEMDEBUG_ENABLED
----------------
Default: ``False``
Whether to enable memory debugging.
.. setting:: MEMDEBUG_NOTIFY
MEMDEBUG_NOTIFY
---------------
Default: ``[]``
When memory debugging is enabled a memory report will be sent to the specified
addresses if this setting is not empty, otherwise the report will be written to
the log.
Example::
MEMDEBUG_NOTIFY = ['user@example.com']
.. setting:: MEMUSAGE_ENABLED
MEMUSAGE_ENABLED
----------------
Default: ``True``
Scope: ``scrapy.extensions.memusage``
Whether to enable the memory usage extension. This extension keeps track of
a peak memory used by the process (it writes it to stats). It can also
optionally shutdown the Scrapy process when it exceeds a memory limit
(see :setting:`MEMUSAGE_LIMIT_MB`), and notify by email when that happened
(see :setting:`MEMUSAGE_NOTIFY_MAIL`).
See :ref:`topics-extensions-ref-memusage`.
.. setting:: MEMUSAGE_LIMIT_MB
MEMUSAGE_LIMIT_MB
-----------------
Default: ``0``
Scope: ``scrapy.extensions.memusage``
The maximum amount of memory to allow (in megabytes) before shutting down
Scrapy (if MEMUSAGE_ENABLED is True). If zero, no check will be performed.
See :ref:`topics-extensions-ref-memusage`.
.. setting:: MEMUSAGE_CHECK_INTERVAL_SECONDS
MEMUSAGE_CHECK_INTERVAL_SECONDS
-------------------------------
.. versionadded:: 1.1
Default: ``60.0``
Scope: ``scrapy.extensions.memusage``
The :ref:`Memory usage extension <topics-extensions-ref-memusage>`
checks the current memory usage, versus the limits set by
:setting:`MEMUSAGE_LIMIT_MB` and :setting:`MEMUSAGE_WARNING_MB`,
at fixed time intervals.
This sets the length of these intervals, in seconds.
See :ref:`topics-extensions-ref-memusage`.
.. setting:: MEMUSAGE_NOTIFY_MAIL
MEMUSAGE_NOTIFY_MAIL
--------------------
Default: ``False``
Scope: ``scrapy.extensions.memusage``
A list of emails to notify if the memory limit has been reached.
Example::
MEMUSAGE_NOTIFY_MAIL = ['user@example.com']
See :ref:`topics-extensions-ref-memusage`.
.. setting:: MEMUSAGE_WARNING_MB
MEMUSAGE_WARNING_MB
-------------------
Default: ``0``
Scope: ``scrapy.extensions.memusage``
The maximum amount of memory to allow (in megabytes) before sending a warning
email notifying about it. If zero, no warning will be produced.
.. setting:: NEWSPIDER_MODULE
NEWSPIDER_MODULE
----------------
Default: ``''``
Module where to create new spiders using the :command:`genspider` command.
Example::
NEWSPIDER_MODULE = 'mybot.spiders_dev'
.. setting:: RANDOMIZE_DOWNLOAD_DELAY
RANDOMIZE_DOWNLOAD_DELAY
------------------------
Default: ``True``
If enabled, Scrapy will wait a random amount of time (between 0.5 * :setting:`DOWNLOAD_DELAY` and 1.5 * :setting:`DOWNLOAD_DELAY`) while fetching requests from the same
website.
This randomization decreases the chance of the crawler being detected (and
subsequently blocked) by sites which analyze requests looking for statistically
significant similarities in the time between their requests.
The randomization policy is the same used by `wget`_ ``--random-wait`` option.
If :setting:`DOWNLOAD_DELAY` is zero (default) this option has no effect.
.. _wget: https://www.gnu.org/software/wget/manual/wget.html
.. setting:: REACTOR_THREADPOOL_MAXSIZE
REACTOR_THREADPOOL_MAXSIZE
--------------------------
Default: ``10``
The maximum limit for Twisted Reactor thread pool size. This is common
multi-purpose thread pool used by various Scrapy components. Threaded
DNS Resolver, BlockingFeedStorage, S3FilesStore just to name a few. Increase
this value if you're experiencing problems with insufficient blocking IO.
.. setting:: REDIRECT_MAX_TIMES
REDIRECT_MAX_TIMES
------------------
Default: ``20``
Defines the maximum times a request can be redirected. After this maximum the
request's response is returned as is. We used Firefox default value for the
same task.
.. setting:: REDIRECT_PRIORITY_ADJUST
REDIRECT_PRIORITY_ADJUST
------------------------
Default: ``+2``
Scope: ``scrapy.downloadermiddlewares.redirect.RedirectMiddleware``
Adjust redirect request priority relative to original request:
- **a positive priority adjust (default) means higher priority.**
- a negative priority adjust means lower priority.
.. setting:: RETRY_PRIORITY_ADJUST
RETRY_PRIORITY_ADJUST
---------------------
Default: ``-1``
Scope: ``scrapy.downloadermiddlewares.retry.RetryMiddleware``
Adjust retry request priority relative to original request:
- a positive priority adjust means higher priority.
- **a negative priority adjust (default) means lower priority.**
.. setting:: ROBOTSTXT_OBEY
ROBOTSTXT_OBEY
--------------
Default: ``False``
Scope: ``scrapy.downloadermiddlewares.robotstxt``
If enabled, Scrapy will respect robots.txt policies. For more information see
:ref:`topics-dlmw-robots`.
.. note::
While the default value is ``False`` for historical reasons,
this option is enabled by default in settings.py file generated
by ``scrapy startproject`` command.
.. setting:: ROBOTSTXT_PARSER
ROBOTSTXT_PARSER
----------------
Default: ``'scrapy.robotstxt.ProtegoRobotParser'``
The parser backend to use for parsing ``robots.txt`` files. For more information see
:ref:`topics-dlmw-robots`.
.. setting:: ROBOTSTXT_USER_AGENT
ROBOTSTXT_USER_AGENT
^^^^^^^^^^^^^^^^^^^^
Default: ``None``
The user agent string to use for matching in the robots.txt file. If ``None``,
the User-Agent header you are sending with the request or the
:setting:`USER_AGENT` setting (in that order) will be used for determining
the user agent to use in the robots.txt file.
.. setting:: SCHEDULER
SCHEDULER
---------
Default: ``'scrapy.core.scheduler.Scheduler'``
The scheduler to use for crawling.
.. setting:: SCHEDULER_DEBUG
SCHEDULER_DEBUG
---------------
Default: ``False``
Setting to ``True`` will log debug information about the requests scheduler.
This currently logs (only once) if the requests cannot be serialized to disk.
Stats counter (``scheduler/unserializable``) tracks the number of times this happens.
Example entry in logs::
1956-01-31 00:00:00+0800 [scrapy.core.scheduler] ERROR: Unable to serialize request:
<GET http://example.com> - reason: cannot serialize <Request at 0x9a7c7ec>
(type Request)> - no more unserializable requests will be logged
(see 'scheduler/unserializable' stats counter)
.. setting:: SCHEDULER_DISK_QUEUE
SCHEDULER_DISK_QUEUE
--------------------
Default: ``'scrapy.squeues.PickleLifoDiskQueue'``
Type of disk queue that will be used by scheduler. Other available types are
``scrapy.squeues.PickleFifoDiskQueue``, ``scrapy.squeues.MarshalFifoDiskQueue``,
``scrapy.squeues.MarshalLifoDiskQueue``.
.. setting:: SCHEDULER_MEMORY_QUEUE
SCHEDULER_MEMORY_QUEUE
----------------------
Default: ``'scrapy.squeues.LifoMemoryQueue'``
Type of in-memory queue used by scheduler. Other available type is:
``scrapy.squeues.FifoMemoryQueue``.
.. setting:: SCHEDULER_PRIORITY_QUEUE
SCHEDULER_PRIORITY_QUEUE
------------------------
Default: ``'scrapy.pqueues.ScrapyPriorityQueue'``
Type of priority queue used by the scheduler. Another available type is
``scrapy.pqueues.DownloaderAwarePriorityQueue``.
``scrapy.pqueues.DownloaderAwarePriorityQueue`` works better than
``scrapy.pqueues.ScrapyPriorityQueue`` when you crawl many different
domains in parallel. But currently ``scrapy.pqueues.DownloaderAwarePriorityQueue``
does not work together with :setting:`CONCURRENT_REQUESTS_PER_IP`.
.. setting:: SCRAPER_SLOT_MAX_ACTIVE_SIZE
SCRAPER_SLOT_MAX_ACTIVE_SIZE
----------------------------
Default: ``5000000``
Soft limit (in bytes) for response data being processed.
While the sum of the sizes of all responses being processed is above this value,
Scrapy does not process new requests.
.. setting:: SPIDER_CONTRACTS
SPIDER_CONTRACTS
----------------
Default:: ``{}``
A dict containing the spider contracts enabled in your project, used for
testing spiders. For more info see :ref:`topics-contracts`.
.. setting:: SPIDER_CONTRACTS_BASE
SPIDER_CONTRACTS_BASE
---------------------
Default::
{
'scrapy.contracts.default.UrlContract' : 1,
'scrapy.contracts.default.ReturnsContract': 2,
'scrapy.contracts.default.ScrapesContract': 3,
}
A dict containing the Scrapy contracts enabled by default in Scrapy. You should
never modify this setting in your project, modify :setting:`SPIDER_CONTRACTS`
instead. For more info see :ref:`topics-contracts`.
You can disable any of these contracts by assigning ``None`` to their class
path in :setting:`SPIDER_CONTRACTS`. E.g., to disable the built-in
``ScrapesContract``, place this in your ``settings.py``::
SPIDER_CONTRACTS = {
'scrapy.contracts.default.ScrapesContract': None,
}
.. setting:: SPIDER_LOADER_CLASS
SPIDER_LOADER_CLASS
-------------------
Default: ``'scrapy.spiderloader.SpiderLoader'``
The class that will be used for loading spiders, which must implement the
:ref:`topics-api-spiderloader`.
.. setting:: SPIDER_LOADER_WARN_ONLY
SPIDER_LOADER_WARN_ONLY
-----------------------
.. versionadded:: 1.3.3
Default: ``False``
By default, when Scrapy tries to import spider classes from :setting:`SPIDER_MODULES`,
it will fail loudly if there is any ``ImportError`` exception.
But you can choose to silence this exception and turn it into a simple
warning by setting ``SPIDER_LOADER_WARN_ONLY = True``.
.. note::
Some :ref:`scrapy commands <topics-commands>` run with this setting to ``True``
already (i.e. they will only issue a warning and will not fail)
since they do not actually need to load spider classes to work:
:command:`scrapy runspider <runspider>`,
:command:`scrapy settings <settings>`,
:command:`scrapy startproject <startproject>`,
:command:`scrapy version <version>`.
.. setting:: SPIDER_MIDDLEWARES
SPIDER_MIDDLEWARES
------------------
Default:: ``{}``
A dict containing the spider middlewares enabled in your project, and their
orders. For more info see :ref:`topics-spider-middleware-setting`.
.. setting:: SPIDER_MIDDLEWARES_BASE
SPIDER_MIDDLEWARES_BASE
-----------------------
Default::
{
'scrapy.spidermiddlewares.httperror.HttpErrorMiddleware': 50,
'scrapy.spidermiddlewares.offsite.OffsiteMiddleware': 500,
'scrapy.spidermiddlewares.referer.RefererMiddleware': 700,
'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware': 800,
'scrapy.spidermiddlewares.depth.DepthMiddleware': 900,
}
A dict containing the spider middlewares enabled by default in Scrapy, and
their orders. Low orders are closer to the engine, high orders are closer to
the spider. For more info see :ref:`topics-spider-middleware-setting`.
.. setting:: SPIDER_MODULES
SPIDER_MODULES
--------------
Default: ``[]``
A list of modules where Scrapy will look for spiders.
Example::
SPIDER_MODULES = ['mybot.spiders_prod', 'mybot.spiders_dev']
.. setting:: STATS_CLASS
STATS_CLASS
-----------
Default: ``'scrapy.statscollectors.MemoryStatsCollector'``
The class to use for collecting stats, who must implement the
:ref:`topics-api-stats`.
.. setting:: STATS_DUMP
STATS_DUMP
----------
Default: ``True``
Dump the :ref:`Scrapy stats <topics-stats>` (to the Scrapy log) once the spider
finishes.
For more info see: :ref:`topics-stats`.
.. setting:: STATSMAILER_RCPTS
STATSMAILER_RCPTS
-----------------
Default: ``[]`` (empty list)
Send Scrapy stats after spiders finish scraping. See
:class:`~scrapy.extensions.statsmailer.StatsMailer` for more info.
.. setting:: TELNETCONSOLE_ENABLED
TELNETCONSOLE_ENABLED
---------------------
Default: ``True``
A boolean which specifies if the :ref:`telnet console <topics-telnetconsole>`
will be enabled (provided its extension is also enabled).
.. setting:: TELNETCONSOLE_PORT
TELNETCONSOLE_PORT
------------------
Default: ``[6023, 6073]``
The port range to use for the telnet console. If set to ``None`` or ``0``, a
dynamically assigned port is used. For more info see
:ref:`topics-telnetconsole`.
.. setting:: TEMPLATES_DIR
TEMPLATES_DIR
-------------
Default: ``templates`` dir inside scrapy module
The directory where to look for templates when creating new projects with
:command:`startproject` command and new spiders with :command:`genspider`
command.
The project name must not conflict with the name of custom files or directories
in the ``project`` subdirectory.
.. setting:: URLLENGTH_LIMIT
URLLENGTH_LIMIT
---------------
Default: ``2083``
Scope: ``spidermiddlewares.urllength``
The maximum URL length to allow for crawled URLs. For more information about
the default value for this setting see: https://boutell.com/newfaq/misc/urllength.html
.. setting:: USER_AGENT
USER_AGENT
----------
Default: ``"Scrapy/VERSION (+https://scrapy.org)"``
The default User-Agent to use when crawling, unless overridden. This user agent is
also used by :class:`~scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware`
if :setting:`ROBOTSTXT_USER_AGENT` setting is ``None`` and
there is no overridding User-Agent header specified for the request.
Settings documented elsewhere:
------------------------------
The following settings are documented elsewhere, please check each specific
case to see how to enable and use them.
.. settingslist::
.. _Amazon web services: https://aws.amazon.com/
.. _breadth-first order: https://en.wikipedia.org/wiki/Breadth-first_search
.. _depth-first order: https://en.wikipedia.org/wiki/Depth-first_search