piplines 5個 方法 html
import json import os import requests class JsonPipeline(object): def __init__(self): self.file = open('xiaohua.txt', 'w') def process_item(self, item, spider): v = json.dumps(dict(item), ensure_ascii=False) self.file.write(v) self.file.write('\n') self.file.flush() return item class FilePipeline(object): def __init__(self): if not os.path.exists('imgs'): os.makedirs('imgs') def process_item(self, item, spider): response = requests.get(item['url'], stream=True) file_name = '%s_%s.jpg' % (item['name'], item['school']) with open(os.path.join('imgs', file_name), mode='wb') as f: f.write(response.content) return item pipelines
ITEM_PIPELINES = { 'spider1.pipelines.JsonPipeline': 100, 'spider1.pipelines.FilePipeline': 300, } # 每行後面的整型值,肯定了他們運行的順序,item按數字從低到高的順序,經過pipeline,一般將這些數字定義在0-1000範圍內。
對於pipeline能夠作更多,以下:python
from scrapy.exceptions import DropItem class CustomPipeline(object): def __init__(self,v): self.value = v def process_item(self, item, spider): # 操做並進行持久化 # return表示會被後續的pipeline繼續處理 return item # 表示將item丟棄,不會被後續pipeline處理 # raise DropItem() @classmethod def from_crawler(cls, crawler): """ 初始化時候,用於建立pipeline對象 :param crawler: :return: """ val = crawler.settings.getint('MMMM') return cls(val) def open_spider(self,spider): """ 爬蟲開始執行時,調用 :param spider: :return: """ print('000000') def close_spider(self,spider): """ 爬蟲關閉時,被調用 :param spider: :return: """ print('111111') 自定義pipeline
********************中間件****************************react
class SpiderMiddleware(object): def process_spider_input(self,response, spider): """ 下載完成,執行,而後交給parse處理 :param response: :param spider: :return: """ pass def process_spider_output(self,response, result, spider): """ spider處理完成,返回時調用 :param response: :param result: :param spider: :return: 必須返回包含 Request 或 Item 對象的可迭代對象(iterable) """ return result def process_spider_exception(self,response, exception, spider): """ 異常調用 :param response: :param exception: :param spider: :return: None,繼續交給後續中間件處理異常;含 Response 或 Item 的可迭代對象(iterable),交給調度器或pipeline """ return None def process_start_requests(self,start_requests, spider): """ 爬蟲啓動時調用 :param start_requests: :param spider: :return: 包含 Request 對象的可迭代對象 """ return start_requests 爬蟲中間件
class DownMiddleware1(object): def process_request(self, request, spider): """ 請求須要被下載時,通過全部下載器中間件的process_request調用 :param request: :param spider: :return: None,繼續後續中間件去下載; Response對象,中止process_request的執行,開始執行process_response Request對象,中止中間件的執行,將Request從新調度器 raise IgnoreRequest異常,中止process_request的執行,開始執行process_exception """ pass def process_response(self, request, response, spider): """ spider處理完成,返回時調用 :param response: :param result: :param spider: :return: Response 對象:轉交給其餘中間件process_response Request 對象:中止中間件,request會被從新調度下載 raise IgnoreRequest 異常:調用Request.errback """ print('response1') return response def process_exception(self, request, exception, spider): """ 當下載處理器(download handler)或 process_request() (下載中間件)拋出異常 :param response: :param exception: :param spider: :return: None:繼續交給後續中間件處理異常; Response對象:中止後續process_exception方法 Request對象:中止中間件,request將會被從新調用下載 """ return None 下載器中間件
=======================自定製命令=========================================web
from scrapy.commands import ScrapyCommand from scrapy.utils.project import get_project_settings class Command(ScrapyCommand): requires_project = True def syntax(self): return '[options]' def short_desc(self): return 'Runs all of the spiders' def run(self, args, opts): spider_list = self.crawler_process.spiders.list() for name in spider_list: self.crawler_process.crawl(name, **opts.__dict__) self.crawler_process.start() crawlall.py
----------------------------------------------自定義擴展-------------------------------------------------redis
自定義擴展時,利用信號在指定位置註冊制定操做算法
from scrapy import signals class MyExtension(object): def __init__(self, value): self.value = value @classmethod def from_crawler(cls, crawler): val = crawler.settings.getint('MMMM') ext = cls(val) crawler.signals.connect(ext.spider_opened, signal=signals.spider_opened) crawler.signals.connect(ext.spider_closed, signal=signals.spider_closed) return ext def spider_opened(self, spider): print('open') def spider_closed(self, spider): print('close')
******************************************避免重複訪問***********************************************json
scrapy默認使用 scrapy.dupefilter.RFPDupeFilter 進行去重,相關配置有:緩存
DUPEFILTER_CLASS
=
'scrapy.dupefilter.RFPDupeFilter'
cookie
DUPEFILTER_DEBUG
=
False
JOBDIR
=
"保存範文記錄的日誌路徑,如:/root/"
# 最終路徑爲 /root/requests.seen
class RepeatUrl: def __init__(self): self.visited_url = set() @classmethod def from_settings(cls, settings): """ 初始化時,調用 :param settings: :return: """ return cls() def request_seen(self, request): """ 檢測當前請求是否已經被訪問過 :param request: :return: True表示已經訪問過;False表示未訪問過 """ if request.url in self.visited_url: return True self.visited_url.add(request.url) return False def open(self): """ 開始爬去請求時,調用 :return: """ print('open replication') def close(self, reason): """ 結束爬蟲爬取時,調用 :param reason: :return: """ print('close replication') def log(self, request, spider): """ 記錄日誌 :param request: :param spider: :return: """ print('repeat', request.url) 自定義URL去重操做
# -*- coding: utf-8 -*- # Scrapy settings for step8_king project # # For simplicity, this file contains only settings considered important or # commonly used. You can find more settings consulting the documentation: # # http://doc.scrapy.org/en/latest/topics/settings.html # http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html # http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html # 1. 爬蟲名稱 BOT_NAME = 'step8_king' # 2. 爬蟲應用路徑 SPIDER_MODULES = ['step8_king.spiders'] NEWSPIDER_MODULE = 'step8_king.spiders' # Crawl responsibly by identifying yourself (and your website) on the user-agent # 3. 客戶端 user-agent請求頭 # USER_AGENT = 'step8_king (+http://www.yourdomain.com)' # Obey robots.txt rules # 4. 禁止爬蟲配置 # ROBOTSTXT_OBEY = False # Configure maximum concurrent requests performed by Scrapy (default: 16) # 5. 併發請求數 # CONCURRENT_REQUESTS = 4 # Configure a delay for requests for the same website (default: 0) # See http://scrapy.readthedocs.org/en/latest/topics/settings.html#download-delay # See also autothrottle settings and docs # 6. 延遲下載秒數 # DOWNLOAD_DELAY = 2 # The download delay setting will honor only one of: # 7. 單域名訪問併發數,而且延遲下次秒數也應用在每一個域名 # CONCURRENT_REQUESTS_PER_DOMAIN = 2 # 單IP訪問併發數,若是有值則忽略:CONCURRENT_REQUESTS_PER_DOMAIN,而且延遲下次秒數也應用在每一個IP # CONCURRENT_REQUESTS_PER_IP = 3 # Disable cookies (enabled by default) # 8. 是否支持cookie,cookiejar進行操做cookie # COOKIES_ENABLED = True # COOKIES_DEBUG = True # Disable Telnet Console (enabled by default) # 9. Telnet用於查看當前爬蟲的信息,操做爬蟲等... # 使用telnet ip port ,而後經過命令操做 # TELNETCONSOLE_ENABLED = True # TELNETCONSOLE_HOST = '127.0.0.1' # TELNETCONSOLE_PORT = [6023,] # 10. 默認請求頭 # Override the default request headers: # DEFAULT_REQUEST_HEADERS = { # 'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8', # 'Accept-Language': 'en', # } # Configure item pipelines # See http://scrapy.readthedocs.org/en/latest/topics/item-pipeline.html # 11. 定義pipeline處理請求 # ITEM_PIPELINES = { # 'step8_king.pipelines.JsonPipeline': 700, # 'step8_king.pipelines.FilePipeline': 500, # } # 12. 自定義擴展,基於信號進行調用 # Enable or disable extensions # See http://scrapy.readthedocs.org/en/latest/topics/extensions.html # EXTENSIONS = { # # 'step8_king.extensions.MyExtension': 500, # } # 13. 爬蟲容許的最大深度,能夠經過meta查看當前深度;0表示無深度 # DEPTH_LIMIT = 3 # 14. 爬取時,0表示深度優先Lifo(默認);1表示廣度優先FiFo # 後進先出,深度優先 # DEPTH_PRIORITY = 0 # SCHEDULER_DISK_QUEUE = 'scrapy.squeue.PickleLifoDiskQueue' # SCHEDULER_MEMORY_QUEUE = 'scrapy.squeue.LifoMemoryQueue' # 先進先出,廣度優先 # DEPTH_PRIORITY = 1 # SCHEDULER_DISK_QUEUE = 'scrapy.squeue.PickleFifoDiskQueue' # SCHEDULER_MEMORY_QUEUE = 'scrapy.squeue.FifoMemoryQueue' # 15. 調度器隊列 # SCHEDULER = 'scrapy.core.scheduler.Scheduler' # from scrapy.core.scheduler import Scheduler # 16. 訪問URL去重 # DUPEFILTER_CLASS = 'step8_king.duplication.RepeatUrl' # Enable and configure the AutoThrottle extension (disabled by default) # See http://doc.scrapy.org/en/latest/topics/autothrottle.html """ 17. 自動限速算法 from scrapy.contrib.throttle import AutoThrottle 自動限速設置 1. 獲取最小延遲 DOWNLOAD_DELAY 2. 獲取最大延遲 AUTOTHROTTLE_MAX_DELAY 3. 設置初始下載延遲 AUTOTHROTTLE_START_DELAY 4. 當請求下載完成後,獲取其"鏈接"時間 latency,即:請求鏈接到接受到響應頭之間的時間 5. 用於計算的... AUTOTHROTTLE_TARGET_CONCURRENCY target_delay = latency / self.target_concurrency new_delay = (slot.delay + target_delay) / 2.0 # 表示上一次的延遲時間 new_delay = max(target_delay, new_delay) new_delay = min(max(self.mindelay, new_delay), self.maxdelay) slot.delay = new_delay """ # 開始自動限速 # AUTOTHROTTLE_ENABLED = True # The initial download delay # 初始下載延遲 # AUTOTHROTTLE_START_DELAY = 5 # The maximum download delay to be set in case of high latencies # 最大下載延遲 # AUTOTHROTTLE_MAX_DELAY = 10 # The average number of requests Scrapy should be sending in parallel to each remote server # 平均每秒併發數 # AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0 # Enable showing throttling stats for every response received: # 是否顯示 # AUTOTHROTTLE_DEBUG = True # Enable and configure HTTP caching (disabled by default) # See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings """ 18. 啓用緩存 目的用於將已經發送的請求或相應緩存下來,以便之後使用 from scrapy.downloadermiddlewares.httpcache import HttpCacheMiddleware from scrapy.extensions.httpcache import DummyPolicy from scrapy.extensions.httpcache import FilesystemCacheStorage """ # 是否啓用緩存策略 # HTTPCACHE_ENABLED = True # 緩存策略:全部請求均緩存,下次在請求直接訪問原來的緩存便可 # HTTPCACHE_POLICY = "scrapy.extensions.httpcache.DummyPolicy" # 緩存策略:根據Http響應頭:Cache-Control、Last-Modified 等進行緩存的策略 # HTTPCACHE_POLICY = "scrapy.extensions.httpcache.RFC2616Policy" # 緩存超時時間 # HTTPCACHE_EXPIRATION_SECS = 0 # 緩存保存路徑 # HTTPCACHE_DIR = 'httpcache' # 緩存忽略的Http狀態碼 # HTTPCACHE_IGNORE_HTTP_CODES = [] # 緩存存儲的插件 # HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage' """ 19. 代理,須要在環境變量中設置 from scrapy.contrib.downloadermiddleware.httpproxy import HttpProxyMiddleware 方式一:使用默認 os.environ { http_proxy:http://root:woshiniba@192.168.11.11:9999/ https_proxy:http://192.168.11.11:9999/ } 方式二:使用自定義下載中間件 def to_bytes(text, encoding=None, errors='strict'): if isinstance(text, bytes): return text if not isinstance(text, six.string_types): raise TypeError('to_bytes must receive a unicode, str or bytes ' 'object, got %s' % type(text).__name__) if encoding is None: encoding = 'utf-8' return text.encode(encoding, errors) class ProxyMiddleware(object): def process_request(self, request, spider): PROXIES = [ {'ip_port': '111.11.228.75:80', 'user_pass': ''}, {'ip_port': '120.198.243.22:80', 'user_pass': ''}, {'ip_port': '111.8.60.9:8123', 'user_pass': ''}, {'ip_port': '101.71.27.120:80', 'user_pass': ''}, {'ip_port': '122.96.59.104:80', 'user_pass': ''}, {'ip_port': '122.224.249.122:8088', 'user_pass': ''}, ] proxy = random.choice(PROXIES) if proxy['user_pass'] is not None: request.meta['proxy'] = to_bytes("http://%s" % proxy['ip_port']) encoded_user_pass = base64.encodestring(to_bytes(proxy['user_pass'])) request.headers['Proxy-Authorization'] = to_bytes('Basic ' + encoded_user_pass) print "**************ProxyMiddleware have pass************" + proxy['ip_port'] else: print "**************ProxyMiddleware no pass************" + proxy['ip_port'] request.meta['proxy'] = to_bytes("http://%s" % proxy['ip_port']) DOWNLOADER_MIDDLEWARES = { 'step8_king.middlewares.ProxyMiddleware': 500, } """ """ 20. Https訪問 Https訪問時有兩種狀況: 1. 要爬取網站使用的可信任證書(默認支持) DOWNLOADER_HTTPCLIENTFACTORY = "scrapy.core.downloader.webclient.ScrapyHTTPClientFactory" DOWNLOADER_CLIENTCONTEXTFACTORY = "scrapy.core.downloader.contextfactory.ScrapyClientContextFactory" 2. 要爬取網站使用的自定義證書 DOWNLOADER_HTTPCLIENTFACTORY = "scrapy.core.downloader.webclient.ScrapyHTTPClientFactory" DOWNLOADER_CLIENTCONTEXTFACTORY = "step8_king.https.MySSLFactory" # https.py from scrapy.core.downloader.contextfactory import ScrapyClientContextFactory from twisted.internet.ssl import (optionsForClientTLS, CertificateOptions, PrivateCertificate) class MySSLFactory(ScrapyClientContextFactory): def getCertificateOptions(self): from OpenSSL import crypto v1 = crypto.load_privatekey(crypto.FILETYPE_PEM, open('/Users/wupeiqi/client.key.unsecure', mode='r').read()) v2 = crypto.load_certificate(crypto.FILETYPE_PEM, open('/Users/wupeiqi/client.pem', mode='r').read()) return CertificateOptions( privateKey=v1, # pKey對象 certificate=v2, # X509對象 verify=False, method=getattr(self, 'method', getattr(self, '_ssl_method', None)) ) 其餘: 相關類 scrapy.core.downloader.handlers.http.HttpDownloadHandler scrapy.core.downloader.webclient.ScrapyHTTPClientFactory scrapy.core.downloader.contextfactory.ScrapyClientContextFactory 相關配置 DOWNLOADER_HTTPCLIENTFACTORY DOWNLOADER_CLIENTCONTEXTFACTORY """ """ 21. 爬蟲中間件 class SpiderMiddleware(object): def process_spider_input(self,response, spider): ''' 下載完成,執行,而後交給parse處理 :param response: :param spider: :return: ''' pass def process_spider_output(self,response, result, spider): ''' spider處理完成,返回時調用 :param response: :param result: :param spider: :return: 必須返回包含 Request 或 Item 對象的可迭代對象(iterable) ''' return result def process_spider_exception(self,response, exception, spider): ''' 異常調用 :param response: :param exception: :param spider: :return: None,繼續交給後續中間件處理異常;含 Response 或 Item 的可迭代對象(iterable),交給調度器或pipeline ''' return None def process_start_requests(self,start_requests, spider): ''' 爬蟲啓動時調用 :param start_requests: :param spider: :return: 包含 Request 對象的可迭代對象 ''' return start_requests 內置爬蟲中間件: 'scrapy.contrib.spidermiddleware.httperror.HttpErrorMiddleware': 50, 'scrapy.contrib.spidermiddleware.offsite.OffsiteMiddleware': 500, 'scrapy.contrib.spidermiddleware.referer.RefererMiddleware': 700, 'scrapy.contrib.spidermiddleware.urllength.UrlLengthMiddleware': 800, 'scrapy.contrib.spidermiddleware.depth.DepthMiddleware': 900, """ # from scrapy.contrib.spidermiddleware.referer import RefererMiddleware # Enable or disable spider middlewares # See http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html SPIDER_MIDDLEWARES = { # 'step8_king.middlewares.SpiderMiddleware': 543, } """ 22. 下載中間件 class DownMiddleware1(object): def process_request(self, request, spider): ''' 請求須要被下載時,通過全部下載器中間件的process_request調用 :param request: :param spider: :return: None,繼續後續中間件去下載; Response對象,中止process_request的執行,開始執行process_response Request對象,中止中間件的執行,將Request從新調度器 raise IgnoreRequest異常,中止process_request的執行,開始執行process_exception ''' pass def process_response(self, request, response, spider): ''' spider處理完成,返回時調用 :param response: :param result: :param spider: :return: Response 對象:轉交給其餘中間件process_response Request 對象:中止中間件,request會被從新調度下載 raise IgnoreRequest 異常:調用Request.errback ''' print('response1') return response def process_exception(self, request, exception, spider): ''' 當下載處理器(download handler)或 process_request() (下載中間件)拋出異常 :param response: :param exception: :param spider: :return: None:繼續交給後續中間件處理異常; Response對象:中止後續process_exception方法 Request對象:中止中間件,request將會被從新調用下載 ''' return None 默認下載中間件 { 'scrapy.contrib.downloadermiddleware.robotstxt.RobotsTxtMiddleware': 100, 'scrapy.contrib.downloadermiddleware.httpauth.HttpAuthMiddleware': 300, 'scrapy.contrib.downloadermiddleware.downloadtimeout.DownloadTimeoutMiddleware': 350, 'scrapy.contrib.downloadermiddleware.useragent.UserAgentMiddleware': 400, 'scrapy.contrib.downloadermiddleware.retry.RetryMiddleware': 500, 'scrapy.contrib.downloadermiddleware.defaultheaders.DefaultHeadersMiddleware': 550, 'scrapy.contrib.downloadermiddleware.redirect.MetaRefreshMiddleware': 580, 'scrapy.contrib.downloadermiddleware.httpcompression.HttpCompressionMiddleware': 590, 'scrapy.contrib.downloadermiddleware.redirect.RedirectMiddleware': 600, 'scrapy.contrib.downloadermiddleware.cookies.CookiesMiddleware': 700, 'scrapy.contrib.downloadermiddleware.httpproxy.HttpProxyMiddleware': 750, 'scrapy.contrib.downloadermiddleware.chunked.ChunkedTransferMiddleware': 830, 'scrapy.contrib.downloadermiddleware.stats.DownloaderStats': 850, 'scrapy.contrib.downloadermiddleware.httpcache.HttpCacheMiddleware': 900, } """ # from scrapy.contrib.downloadermiddleware.httpauth import HttpAuthMiddleware # Enable or disable downloader middlewares # See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html # DOWNLOADER_MIDDLEWARES = { # 'step8_king.middlewares.DownMiddleware1': 100, # 'step8_king.middlewares.DownMiddleware2': 500, # } settings
#!/usr/bin/env python # -*- coding:utf-8 -*- import types from twisted.internet import defer from twisted.web.client import getPage from twisted.internet import reactor class Request(object): def __init__(self, url, callback): self.url = url self.callback = callback self.priority = 0 class HttpResponse(object): def __init__(self, content, request): self.content = content self.request = request class ChouTiSpider(object): def start_requests(self): url_list = ['http://www.cnblogs.com/', 'http://www.bing.com'] for url in url_list: yield Request(url=url, callback=self.parse) def parse(self, response): print(response.request.url) # yield Request(url="http://www.baidu.com", callback=self.parse) from queue import Queue Q = Queue() class CallLaterOnce(object): def __init__(self, func, *a, **kw): self._func = func self._a = a self._kw = kw self._call = None def schedule(self, delay=0): if self._call is None: self._call = reactor.callLater(delay, self) def cancel(self): if self._call: self._call.cancel() def __call__(self): self._call = None return self._func(*self._a, **self._kw) class Engine(object): def __init__(self): self.nextcall = None self.crawlling = [] self.max = 5 self._closewait = None def get_response(self,content, request): response = HttpResponse(content, request) gen = request.callback(response) if isinstance(gen, types.GeneratorType): for req in gen: req.priority = request.priority + 1 Q.put(req) def rm_crawlling(self,response,d): self.crawlling.remove(d) def _next_request(self,spider): if Q.qsize() == 0 and len(self.crawlling) == 0: self._closewait.callback(None) if len(self.crawlling) >= 5: return while len(self.crawlling) < 5: try: req = Q.get(block=False) except Exception as e: req = None if not req: return d = getPage(req.url.encode('utf-8')) self.crawlling.append(d) d.addCallback(self.get_response, req) d.addCallback(self.rm_crawlling,d) d.addCallback(lambda _: self.nextcall.schedule()) @defer.inlineCallbacks def crawl(self): spider = ChouTiSpider() start_requests = iter(spider.start_requests()) flag = True while flag: try: req = next(start_requests) Q.put(req) except StopIteration as e: flag = False self.nextcall = CallLaterOnce(self._next_request,spider) self.nextcall.schedule() self._closewait = defer.Deferred() yield self._closewait @defer.inlineCallbacks def pp(self): yield self.crawl() _active = set() obj = Engine() d = obj.crawl() _active.add(d) li = defer.DeferredList(_active) li.addBoth(lambda _,*a,**kw: reactor.stop()) reactor.run() 參考版
***********************************scrapy-redis***********************併發