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: Built-in settings reference.
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.
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:
Command line options (most precedence)
Settings per-spider
Project settings module
Default settings per-command
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 Settings API 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.
Example:
scrapy crawl myspider -s LOG_FILE=scrapy.log
2. Settings per-spider¶
Spiders (See the 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 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 Scrapy tool 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 Built-in settings reference section.
Import paths and classes¶
New in version 2.4.0.
When a setting references a callable object to be imported by Scrapy, such as a class or a function, there are two different ways you can specify that object:
As a string containing the import path of that object
As the object itself
For example:
from mybot.pipelines.validate import ValidateMyItem
ITEM_PIPELINES = {
# passing the classname...
ValidateMyItem: 300,
# ...equals passing the class path
'mybot.pipelines.validate.ValidateMyItem': 300,
}
Note
Passing non-callable objects is not supported.
How to access settings¶
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(f"Existing settings: {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
from_crawler()
method.
Settings can be accessed through the scrapy.crawler.Crawler.settings
attribute of the Crawler that is passed to from_crawler
method in
extensions, middlewares and item pipelines:
class MyExtension:
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 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.
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.
AWS_ACCESS_KEY_ID¶
Default: None
The AWS access key used by code that requires access to Amazon Web services, such as the S3 feed storage backend.
AWS_SECRET_ACCESS_KEY¶
Default: None
The AWS secret key used by code that requires access to Amazon Web services, such as the S3 feed storage backend.
AWS_ENDPOINT_URL¶
Default: None
Endpoint URL used for S3-like storage, for example Minio or s3.scality.
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.
AWS_VERIFY¶
Default: None
Verify SSL connection between Scrapy and S3 or S3-like storage. By default SSL verification will occur.
AWS_REGION_NAME¶
Default: None
The name of the region associated with the AWS client.
ASYNCIO_EVENT_LOOP¶
Default: None
Import path of a given asyncio
event loop class.
If the asyncio reactor is enabled (see TWISTED_REACTOR
) this setting can be used to specify the
asyncio event loop to be used with it. Set the setting to the import path of the
desired asyncio event loop class. If the setting is set to None
the default asyncio
event loop will be used.
If you are installing the asyncio reactor manually using the install_reactor()
function, you can use the event_loop_path
parameter to indicate the import path of the event loop
class to be used.
Note that the event loop class must inherit from asyncio.AbstractEventLoop
.
Caution
Please be aware that, when using a non-default event loop
(either defined via ASYNCIO_EVENT_LOOP
or installed with
install_reactor()
), Scrapy will call
asyncio.set_event_loop()
, which will set the specified event loop
as the current loop for the current OS thread.
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 startproject
command.
CONCURRENT_ITEMS¶
Default: 100
Maximum number of concurrent items (per response) to process in parallel in item pipelines.
CONCURRENT_REQUESTS¶
Default: 16
The maximum number of concurrent (i.e. simultaneous) requests that will be performed by the Scrapy downloader.
CONCURRENT_REQUESTS_PER_DOMAIN¶
Default: 8
The maximum number of concurrent (i.e. simultaneous) requests that will be performed to any single domain.
See also: AutoThrottle extension and its
AUTOTHROTTLE_TARGET_CONCURRENCY
option.
CONCURRENT_REQUESTS_PER_IP¶
Default: 0
The maximum number of concurrent (i.e. simultaneous) requests that will be
performed to any single IP. If non-zero, the
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 DOWNLOAD_DELAY
and
AutoThrottle extension: if CONCURRENT_REQUESTS_PER_IP
is non-zero, download delay is enforced per IP, not per domain.
DEFAULT_ITEM_CLASS¶
Default: 'scrapy.item.Item'
The default class that will be used for instantiating items in the the Scrapy shell.
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
DefaultHeadersMiddleware
.
Caution
Cookies set via the Cookie
header are not considered by the
CookiesMiddleware. If you need to set cookies for a request, use the
Request.cookies
parameter. This is a known
current limitation that is being worked on.
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.
DEPTH_PRIORITY¶
Default: 0
Scope: scrapy.spidermiddlewares.depth.DepthMiddleware
An integer that is used to adjust the priority
of
a 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 Does Scrapy crawl in breadth-first or depth-first order?.
Note
This setting adjusts priority in the opposite way compared to
other priority settings REDIRECT_PRIORITY_ADJUST
and RETRY_PRIORITY_ADJUST
.
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.
DNSCACHE_ENABLED¶
Default: True
Whether to enable DNS in-memory cache.
DNSCACHE_SIZE¶
Default: 10000
DNS in-memory cache size.
DNS_RESOLVER¶
New in version 2.0.
Default: 'scrapy.resolver.CachingThreadedResolver'
The class to be used to resolve DNS names. The default scrapy.resolver.CachingThreadedResolver
supports specifying a timeout for DNS requests via the DNS_TIMEOUT
setting,
but works only with IPv4 addresses. Scrapy provides an alternative resolver,
scrapy.resolver.CachingHostnameResolver
, which supports IPv4/IPv6 addresses but does not
take the DNS_TIMEOUT
setting into account.
DNS_TIMEOUT¶
Default: 60
Timeout for processing of DNS queries in seconds. Float is supported.
DOWNLOADER¶
Default: 'scrapy.core.downloader.Downloader'
The downloader to use for crawling.
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 really want to use HTTP/1.0 and override
DOWNLOAD_HANDLERS
for http(s)
scheme accordingly,
i.e. to 'scrapy.core.downloader.handlers.http.HTTP10DownloadHandler'
.
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.
If you do use a custom ContextFactory, make sure its __init__
method
accepts a method
parameter (this is the OpenSSL.SSL
method mapping
DOWNLOADER_CLIENT_TLS_METHOD
), a tls_verbose_logging
parameter (bool
) and a tls_ciphers
parameter (see
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.
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’sTLS_method()
(a.k.aSSLv23_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)
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
DOWNLOADER_CLIENTCONTEXTFACTORY
.
DOWNLOADER_MIDDLEWARES¶
Default:: {}
A dict containing the downloader middlewares enabled in your project, and their orders. For more info see Activating a downloader middleware.
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
DOWNLOADER_MIDDLEWARES
instead. For more info see
Activating a downloader middleware.
DOWNLOADER_STATS¶
Default: True
Whether to enable downloader stats collection.
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 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 * DOWNLOAD_DELAY
and 1.5 * DOWNLOAD_DELAY
.
When CONCURRENT_REQUESTS_PER_IP
is non-zero, delays are enforced
per ip address instead of per domain.
You can also change this setting per spider by setting download_delay
spider attribute.
DOWNLOAD_HANDLERS¶
Default: {}
A dict containing the request downloader handlers enabled in your project.
See DOWNLOAD_HANDLERS_BASE
for example format.
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
DOWNLOAD_HANDLERS
instead.
You can disable any of these download handlers by assigning None
to their
URI scheme in DOWNLOAD_HANDLERS
. E.g., to disable the built-in FTP
handler (without replacement), place this in your settings.py
:
DOWNLOAD_HANDLERS = {
'ftp': None,
}
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 download_timeout
spider attribute and per-request using download_timeout
Request.meta key.
DOWNLOAD_MAXSIZE¶
Default: 1073741824
(1024MB)
The maximum response size (in bytes) that downloader will download.
If you want to disable it set to 0.
Note
This size can be set per spider using download_maxsize
spider attribute and per-request using download_maxsize
Request.meta key.
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 download_warnsize
spider attribute and per-request using download_warnsize
Request.meta key.
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
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 RETRY_ENABLED
is True
and this setting is set to True
,
the ResponseFailed([_DataLoss])
failure will be retried as usual.
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 Request
object and return its fingerprint
(a string).
You can disable filtering of duplicate requests by 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 Request
that should not be
filtered.
DUPEFILTER_DEBUG¶
Default: False
By default, RFPDupeFilter
only logs the first duplicate request.
Setting DUPEFILTER_DEBUG
to True
will make it log all duplicate requests.
EDITOR¶
Default: vi
(on Unix systems) or the IDLE editor (on Windows)
The editor to use for editing spiders with the edit
command.
Additionally, if the EDITOR
environment variable is set, the edit
command will prefer it over the default setting.
EXTENSIONS¶
Default:: {}
A dict containing the extensions enabled in your project, and their orders.
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 extensions user guide and the list of available extensions.
FEED_TEMPDIR¶
The Feed Temp dir allows you to set a custom folder to save crawler temporary files before uploading with FTP feed storage and Amazon S3.
FEED_STORAGE_GCS_ACL¶
The Access Control List (ACL) used when storing items to Google Cloud Storage. For more information on how to set this value, please refer to the column JSON API in Google Cloud documentation.
FTP_PASSIVE_MODE¶
Default: True
Whether or not to use passive mode when initiating FTP transfers.
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.
FTP_USER¶
Default: "anonymous"
The username to use for FTP connections when there is no "ftp_user"
in Request
meta.
GCS_PROJECT_ID¶
Default: None
The Project ID that will be used when storing data on Google Cloud Storage.
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,
}
ITEM_PIPELINES_BASE¶
Default: {}
A dict containing the pipelines enabled by default in Scrapy. You should never
modify this setting in your project, modify ITEM_PIPELINES
instead.
LOG_ENABLED¶
Default: True
Whether to enable logging.
LOG_ENCODING¶
Default: 'utf-8'
The encoding to use for logging.
LOG_FILE¶
Default: None
File name to use for logging output. If None
, standard error will be used.
LOG_FORMAT¶
Default: '%(asctime)s [%(name)s] %(levelname)s: %(message)s'
String for formatting log messages. Refer to the Python logging documentation for the qwhole list of available placeholders.
LOG_DATEFORMAT¶
Default: '%Y-%m-%d %H:%M:%S'
String for formatting date/time, expansion of the %(asctime)s
placeholder
in LOG_FORMAT
. Refer to the
Python datetime documentation for the
whole list of available directives.
LOG_FORMATTER¶
Default: scrapy.logformatter.LogFormatter
The class to use for formatting log messages for different actions.
LOG_LEVEL¶
Default: 'DEBUG'
Minimum level to log. Available levels are: CRITICAL, ERROR, WARNING, INFO, DEBUG. For more info see Logging.
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.
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
LOGSTATS_INTERVAL¶
Default: 60.0
The interval (in seconds) between each logging printout of the stats
by LogStats
.
MEMDEBUG_ENABLED¶
Default: False
Whether to enable memory debugging.
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']
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 MEMUSAGE_LIMIT_MB
), and notify by email when that happened
(see MEMUSAGE_NOTIFY_MAIL
).
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.
MEMUSAGE_CHECK_INTERVAL_SECONDS¶
Default: 60.0
Scope: scrapy.extensions.memusage
The Memory usage extension
checks the current memory usage, versus the limits set by
MEMUSAGE_LIMIT_MB
and MEMUSAGE_WARNING_MB
,
at fixed time intervals.
This sets the length of these intervals, in seconds.
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']
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.
NEWSPIDER_MODULE¶
Default: ''
Module where to create new spiders using the genspider
command.
Example:
NEWSPIDER_MODULE = 'mybot.spiders_dev'
RANDOMIZE_DOWNLOAD_DELAY¶
Default: True
If enabled, Scrapy will wait a random amount of time (between 0.5 * DOWNLOAD_DELAY
and 1.5 * 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 DOWNLOAD_DELAY
is zero (default) this option has no effect.
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.
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.
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.
ROBOTSTXT_OBEY¶
Default: False
Scope: scrapy.downloadermiddlewares.robotstxt
If enabled, Scrapy will respect robots.txt policies. For more information see RobotsTxtMiddleware.
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.
ROBOTSTXT_PARSER¶
Default: 'scrapy.robotstxt.ProtegoRobotParser'
The parser backend to use for parsing robots.txt
files. For more information see
RobotsTxtMiddleware.
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
USER_AGENT
setting (in that order) will be used for determining
the user agent to use in the robots.txt file.
SCHEDULER¶
Default: 'scrapy.core.scheduler.Scheduler'
The scheduler to use for crawling.
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)
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
.
SCHEDULER_MEMORY_QUEUE¶
Default: 'scrapy.squeues.LifoMemoryQueue'
Type of in-memory queue used by scheduler. Other available type is:
scrapy.squeues.FifoMemoryQueue
.
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 CONCURRENT_REQUESTS_PER_IP
.
SCRAPER_SLOT_MAX_ACTIVE_SIZE¶
New in version 2.0.
Default: 5_000_000
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.
SPIDER_CONTRACTS¶
Default:: {}
A dict containing the spider contracts enabled in your project, used for testing spiders. For more info see Spiders Contracts.
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 SPIDER_CONTRACTS
instead. For more info see Spiders Contracts.
You can disable any of these contracts by assigning None
to their class
path in SPIDER_CONTRACTS
. E.g., to disable the built-in
ScrapesContract
, place this in your settings.py
:
SPIDER_CONTRACTS = {
'scrapy.contracts.default.ScrapesContract': None,
}
SPIDER_LOADER_CLASS¶
Default: 'scrapy.spiderloader.SpiderLoader'
The class that will be used for loading spiders, which must implement the SpiderLoader API.
SPIDER_LOADER_WARN_ONLY¶
Default: False
By default, when Scrapy tries to import spider classes from 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 scrapy 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:
scrapy runspider
,
scrapy settings
,
scrapy startproject
,
scrapy version
.
SPIDER_MIDDLEWARES¶
Default:: {}
A dict containing the spider middlewares enabled in your project, and their orders. For more info see Activating a spider middleware.
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 Activating a spider middleware.
SPIDER_MODULES¶
Default: []
A list of modules where Scrapy will look for spiders.
Example:
SPIDER_MODULES = ['mybot.spiders_prod', 'mybot.spiders_dev']
STATS_CLASS¶
Default: 'scrapy.statscollectors.MemoryStatsCollector'
The class to use for collecting stats, who must implement the Stats Collector API.
STATS_DUMP¶
Default: True
Dump the Scrapy stats (to the Scrapy log) once the spider finishes.
For more info see: Stats Collection.
STATSMAILER_RCPTS¶
Default: []
(empty list)
Send Scrapy stats after spiders finish scraping. See
StatsMailer
for more info.
TELNETCONSOLE_ENABLED¶
Default: True
A boolean which specifies if the telnet console will be enabled (provided its extension is also enabled).
TEMPLATES_DIR¶
Default: templates
dir inside scrapy module
The directory where to look for templates when creating new projects with
startproject
command and new spiders with genspider
command.
The project name must not conflict with the name of custom files or directories
in the project
subdirectory.
TWISTED_REACTOR¶
New in version 2.0.
Default: None
Import path of a given reactor
.
Scrapy will install this reactor if no other reactor is installed yet, such as
when the scrapy
CLI program is invoked or when using the
CrawlerProcess
class.
If you are using the CrawlerRunner
class, you also
need to install the correct reactor manually. You can do that using
install_reactor()
:
- scrapy.utils.reactor.install_reactor(reactor_path, event_loop_path=None)[source]¶
Installs the
reactor
with the specified import path. Also installs the asyncio event loop with the specified import path if the asyncio reactor is enabled
If a reactor is already installed,
install_reactor()
has no effect.
CrawlerRunner.__init__
raises
Exception
if the installed reactor does not match the
TWISTED_REACTOR
setting; therfore, having top-level
reactor
imports in project files and imported
third-party libraries will make Scrapy raise Exception
when
it checks which reactor is installed.
In order to use the reactor installed by Scrapy:
import scrapy
from twisted.internet import reactor
class QuotesSpider(scrapy.Spider):
name = 'quotes'
def __init__(self, *args, **kwargs):
self.timeout = int(kwargs.pop('timeout', '60'))
super(QuotesSpider, self).__init__(*args, **kwargs)
def start_requests(self):
reactor.callLater(self.timeout, self.stop)
urls = ['http://quotes.toscrape.com/page/1']
for url in urls:
yield scrapy.Request(url=url, callback=self.parse)
def parse(self, response):
for quote in response.css('div.quote'):
yield {'text': quote.css('span.text::text').get()}
def stop(self):
self.crawler.engine.close_spider(self, 'timeout')
which raises Exception
, becomes:
import scrapy
class QuotesSpider(scrapy.Spider):
name = 'quotes'
def __init__(self, *args, **kwargs):
self.timeout = int(kwargs.pop('timeout', '60'))
super(QuotesSpider, self).__init__(*args, **kwargs)
def start_requests(self):
from twisted.internet import reactor
reactor.callLater(self.timeout, self.stop)
urls = ['http://quotes.toscrape.com/page/1']
for url in urls:
yield scrapy.Request(url=url, callback=self.parse)
def parse(self, response):
for quote in response.css('div.quote'):
yield {'text': quote.css('span.text::text').get()}
def stop(self):
self.crawler.engine.close_spider(self, 'timeout')
The default value of the TWISTED_REACTOR
setting is None
, which
means that Scrapy will not attempt to install any specific reactor, and the
default reactor defined by Twisted for the current platform will be used. This
is to maintain backward compatibility and avoid possible problems caused by
using a non-default reactor.
For additional information, see core/howto/choosing-reactor.
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
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 RobotsTxtMiddleware
if 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.