详解scrapy内置中间件的顺序

 {'scrapy.downloadermiddlewares.ajaxcrawl.AjaxCrawlMiddleware': 560, 'scrapy.downloadermiddlewares.cookies.CookiesMiddleware': 700, 'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware': 400, 'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware': 350, 'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware': 300, 'scrapy.downloadermiddlewares.httpcache.HttpCacheMiddleware': 900, 'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware': 590, 'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware': 750, 'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware': 580, 'scrapy.downloadermiddlewares.redirect.RedirectMiddleware': 600, 'scrapy.downloadermiddlewares.retry.RetryMiddleware': 550, 'scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware': 100, 'scrapy.downloadermiddlewares.stats.DownloaderStats': 850, 'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware': 500} 

 {'scrapy.spidermiddlewares.depth.DepthMiddleware': 900, 'scrapy.spidermiddlewares.httperror.HttpErrorMiddleware': 50, 'scrapy.spidermiddlewares.offsite.OffsiteMiddleware': 500, 'scrapy.spidermiddlewares.referer.RefererMiddleware': 700, 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware': 800} 

 {'AJAXCRAWL_ENABLED': False, 'AUTOTHROTTLE_DEBUG': False, 'AUTOTHROTTLE_ENABLED': False, 'AUTOTHROTTLE_MAX_DELAY': 60.0, 'AUTOTHROTTLE_START_DELAY': 5.0, 'AUTOTHROTTLE_TARGET_CONCURRENCY': 1.0, 'BOT_NAME': 'scrapybot', 'CLOSESPIDER_ERRORCOUNT': 0, 'CLOSESPIDER_ITEMCOUNT': 0, 'CLOSESPIDER_PAGECOUNT': 0, 'CLOSESPIDER_TIMEOUT': 0, 'COMMANDS_MODULE': '', 'COMPRESSION_ENABLED': True, 'CONCURRENT_ITEMS': 100, 'CONCURRENT_REQUESTS': 16, 'CONCURRENT_REQUESTS_PER_DOMAIN': 8, 'CONCURRENT_REQUESTS_PER_IP': 0, 'COOKIES_DEBUG': False, 'COOKIES_ENABLED': True, 'DEFAULT_ITEM_CLASS': 'scrapy.item.Item', 'DEFAULT_REQUEST_HEADERS': {'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8', 'Accept-Language': 'en'}, 'DEPTH_LIMIT': 0, 'DEPTH_PRIORITY': 0, 'DEPTH_STATS_VERBOSE': False, 'DNSCACHE_ENABLED': True, 'DNSCACHE_SIZE': 10000, 'DNS_TIMEOUT': 60, 'DOWNLOADER': 'scrapy.core.downloader.Downloader', 'DOWNLOADER_CLIENTCONTEXTFACTORY': 'scrapy.core.downloader.contextfactory.ScrapyClientContextFactory', 'DOWNLOADER_CLIENT_TLS_METHOD': 'TLS', 'DOWNLOADER_HTTPCLIENTFACTORY': 'scrapy.core.downloader.webclient.ScrapyHTTPClientFactory', 'DOWNLOADER_MIDDLEWARES': {}, 'DOWNLOADER_MIDDLEWARES_BASE': {'scrapy.downloadermiddlewares.ajaxcrawl.AjaxCrawlMiddleware': 560, 'scrapy.downloadermiddlewares.cookies.CookiesMiddleware': 700, 'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware': 400, 'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware': 350, 'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware': 300, 'scrapy.downloadermiddlewares.httpcache.HttpCacheMiddleware': 900, 'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware': 590, 'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware': 750, 'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware': 580, 'scrapy.downloadermiddlewares.redirect.RedirectMiddleware': 600, 'scrapy.downloadermiddlewares.retry.RetryMiddleware': 550, 'scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware': 100, 'scrapy.downloadermiddlewares.stats.DownloaderStats': 850, 'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware': 500}, 'DOWNLOADER_STATS': True, 'DOWNLOAD_DELAY': 0, 'DOWNLOAD_FAIL_ON_DATALOSS': True, 'DOWNLOAD_HANDLERS': {}, 'DOWNLOAD_HANDLERS_BASE': {'data': 'scrapy.core.downloader.handlers.datauri.DataURIDownloadHandler', 'file': 'scrapy.core.downloader.handlers.file.FileDownloadHandler', 'ftp': 'scrapy.core.downloader.handlers.ftp.FTPDownloadHandler', 'http': 'scrapy.core.downloader.handlers.http.HTTPDownloadHandler', 'https': 'scrapy.core.downloader.handlers.http.HTTPDownloadHandler', 's3': 'scrapy.core.downloader.handlers.s3.S3DownloadHandler'}, 'DOWNLOAD_MAXSIZE': 1073741824, 'DOWNLOAD_TIMEOUT': 180, 'DOWNLOAD_WARNSIZE': 33554432, 'DUPEFILTER_CLASS': 'scrapy.dupefilters.BaseDupeFilter', 'EDITOR': 'D:\\Program Files (x86)\\Notepad++\\notepad++.exe', 'EXTENSIONS': {}, 'EXTENSIONS_BASE': {'scrapy.extensions.closespider.CloseSpider': 0, 'scrapy.extensions.corestats.CoreStats': 0, 'scrapy.extensions.feedexport.FeedExporter': 0, 'scrapy.extensions.logstats.LogStats': 0, 'scrapy.extensions.memdebug.MemoryDebugger': 0, 'scrapy.extensions.memusage.MemoryUsage': 0, 'scrapy.extensions.spiderstate.SpiderState': 0, 'scrapy.extensions.telnet.TelnetConsole': 0, 'scrapy.extensions.throttle.AutoThrottle': 0}, 'FEED_EXPORTERS': {}, 'FEED_EXPORTERS_BASE': {'csv': 'scrapy.exporters.CsvItemExporter', 'jl': 'scrapy.exporters.JsonLinesItemExporter', 'json': 'scrapy.exporters.JsonItemExporter', 'jsonlines': 'scrapy.exporters.JsonLinesItemExporter', 'marshal': 'scrapy.exporters.MarshalItemExporter', 'pickle': 'scrapy.exporters.PickleItemExporter', 'xml': 'scrapy.exporters.XmlItemExporter'}, 'FEED_EXPORT_ENCODING': None, 'FEED_EXPORT_FIELDS': None, 'FEED_EXPORT_INDENT': 0, 'FEED_FORMAT': 'jsonlines', 'FEED_STORAGES': {}, 'FEED_STORAGES_BASE': {'': 'scrapy.extensions.feedexport.FileFeedStorage', 'file': 'scrapy.extensions.feedexport.FileFeedStorage', 'ftp': 'scrapy.extensions.feedexport.FTPFeedStorage', 's3': 'scrapy.extensions.feedexport.S3FeedStorage', 'stdout': 'scrapy.extensions.feedexport.StdoutFeedStorage'}, 'FEED_STORE_EMPTY': False, 'FEED_TEMPDIR': None, 'FEED_URI': None, 'FEED_URI_PARAMS': None, 'FILES_STORE_GCS_ACL': '', 'FILES_STORE_S3_ACL': 'private', 'FTP_PASSIVE_MODE': True, 'FTP_PASSWORD': 'guest', 'FTP_USER': 'anonymous', 'HTTPCACHE_ALWAYS_STORE': False, 'HTTPCACHE_DBM_MODULE': 'dbm', 'HTTPCACHE_DIR<span style="color:transparent">来源gaodai#ma#com搞*!代#%^码$网</span>': 'httpcache', 'HTTPCACHE_ENABLED': False, 'HTTPCACHE_EXPIRATION_SECS': 0, 'HTTPCACHE_GZIP': False, 'HTTPCACHE_IGNORE_HTTP_CODES': [], 'HTTPCACHE_IGNORE_MISSING': False, 'HTTPCACHE_IGNORE_RESPONSE_CACHE_CONTROLS': [], 'HTTPCACHE_IGNORE_SCHEMES': ['file'], 'HTTPCACHE_POLICY': 'scrapy.extensions.httpcache.DummyPolicy', 'HTTPCACHE_STORAGE': 'scrapy.extensions.httpcache.FilesystemCacheStorage', 'HTTPPROXY_AUTH_ENCODING': 'latin-1', 'HTTPPROXY_ENABLED': True, 'IMAGES_STORE_GCS_ACL': '', 'IMAGES_STORE_S3_ACL': 'private', 'ITEM_PIPELINES': {}, 'ITEM_PIPELINES_BASE': {}, 'ITEM_PROCESSOR': 'scrapy.pipelines.ItemPipelineManager', 'LOGSTATS_INTERVAL': 0, 'LOG_DATEFORMAT': '%Y-%m-%d %H:%M:%S', 'LOG_ENABLED': True, 'LOG_ENCODING': 'utf-8', 'LOG_FILE': None, 'LOG_FORMAT': '%(asctime)s [%(name)s] %(levelname)s: %(message)s', 'LOG_FORMATTER': 'scrapy.logformatter.LogFormatter', 'LOG_LEVEL': 'DEBUG', 'LOG_SHORT_NAMES': False, 'LOG_STDOUT': False, 'MAIL_FROM': 'scrapy@localhost', 'MAIL_HOST': 'localhost', 'MAIL_PASS': None, 'MAIL_PORT': 25, 'MAIL_USER': None, 'MEMDEBUG_ENABLED': False, 'MEMDEBUG_NOTIFY': [], 'MEMUSAGE_CHECK_INTERVAL_SECONDS': 60.0, 'MEMUSAGE_ENABLED': True, 'MEMUSAGE_LIMIT_MB': 0, 'MEMUSAGE_NOTIFY_MAIL': [], 'MEMUSAGE_WARNING_MB': 0, 'METAREFRESH_ENABLED': True, 'METAREFRESH_MAXDELAY': 100, 'NEWSPIDER_MODULE': '', 'RANDOMIZE_DOWNLOAD_DELAY': True, 'REACTOR_THREADPOOL_MAXSIZE': 10, 'REDIRECT_ENABLED': True, 'REDIRECT_MAX_TIMES': 20, 'REDIRECT_PRIORITY_ADJUST': 2, 'REFERER_ENABLED': True, 'REFERRER_POLICY': 'scrapy.spidermiddlewares.referer.DefaultReferrerPolicy', 'RETRY_ENABLED': True, 'RETRY_HTTP_CODES': [500, 502, 503, 504, 522, 524, 408], 'RETRY_PRIORITY_ADJUST': -1, 'RETRY_TIMES': 2, 'ROBOTSTXT_OBEY': False, 'SCHEDULER': 'scrapy.core.scheduler.Scheduler', 'SCHEDULER_DEBUG': False, 'SCHEDULER_DISK_QUEUE': 'scrapy.squeues.PickleLifoDiskQueue', 'SCHEDULER_MEMORY_QUEUE': 'scrapy.squeues.LifoMemoryQueue', 'SCHEDULER_PRIORITY_QUEUE': 'queuelib.PriorityQueue', 'SPIDER_CONTRACTS': {}, 'SPIDER_CONTRACTS_BASE': {'scrapy.contracts.default.ReturnsContract': 2, 'scrapy.contracts.default.ScrapesContract': 3, 'scrapy.contracts.default.UrlContract': 1}, 'SPIDER_LOADER_CLASS': 'scrapy.spiderloader.SpiderLoader', 'SPIDER_LOADER_WARN_ONLY': False, 'SPIDER_MIDDLEWARES': {}, 'SPIDER_MIDDLEWARES_BASE': {'scrapy.spidermiddlewares.depth.DepthMiddleware': 900, 'scrapy.spidermiddlewares.httperror.HttpErrorMiddleware': 50, 'scrapy.spidermiddlewares.offsite.OffsiteMiddleware': 500, 'scrapy.spidermiddlewares.referer.RefererMiddleware': 700, 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware': 800}, 'SPIDER_MODULES': [], 'STATSMAILER_RCPTS': [], 'STATS_CLASS': 'scrapy.statscollectors.MemoryStatsCollector', 'STATS_DUMP': True, 'TELNETCONSOLE_ENABLED': 1, 'TELNETCONSOLE_HOST': '127.0.0.1', 'TELNETCONSOLE_PASSWORD': None, 'TELNETCONSOLE_PORT': [6023, 6073], 'TELNETCONSOLE_USERNAME': 'scrapy', 'TEMPLATES_DIR': 'd:\\python36\\lib\\site-packages\\scrapy\\templates', 'URLLENGTH_LIMIT': 2083, 'USER_AGENT': 'Scrapy/1.6.0 (+https://scrapy.org)', 'KEEP_ALIVE': True}