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scrapy爬虫框架(四) 爬取多个网页

思路：通过判断句子控网站中，下一页是否还有a标签来获取网址，拼接后继续爬取，最终写入json文件中。

juziSpider.py

# -*- coding: utf-8 -*- import scrapy from juzi.items import JuziItem class JuzispiderSpider(scrapy.Spider): name = 'juziSpider' allowed_domains = [''] start_urls = ['https://www.juzikong.com/tags/%E5%8F%A5%E5%AD%90%E8%BF%B7?page=1'] base_domain = "https://www.juzikong.com" def parse(self, response): juzis = response.xpath('//div[@class="list_1fuFI"]//section') print (juzis) print("*" * 50) for juzi in juzis: content = juzi.xpath('.//a//span//span//span//text()').getall() author = juzi.xpath(".//div/span/span/span/span/text()").get() content="".join(content)#列表转化为字符串 if not author: author="匿名" print(author,":",content) item = JuziItem(author=author,content=content) yield item print("*" * 50,) next_url = response.xpath("//button[@class='btn-next']//a/@href").get() if not next_url: return else: yield scrapy.Request(self.base_domain+next_url,callback=self.parse)

settings.py

# -*- coding: utf-8 -*- # Scrapy settings for juzi project # # For simplicity, this file contains only settings considered important or # commonly used. You can find more settings consulting the documentation: # # https://docs.scrapy.org/en/latest/topics/settings.html # https://docs.scrapy.org/en/latest/topics/downloader-middleware.html # https://docs.scrapy.org/en/latest/topics/spider-middleware.html BOT_NAME = 'juzi' SPIDER_MODULES = ['juzi.spiders'] NEWSPIDER_MODULE = 'juzi.spiders' # Crawl responsibly by identifying yourself (and your website) on the user-agent #USER_AGENT = 'juzi (+)' # Obey robots.txt rules ROBOTSTXT_OBEY = False # Configure maximum concurrent requests performed by Scrapy (default: 16) #CONCURRENT_REQUESTS = 32 # Configure a delay for requests for the same website (default: 0) # See https://docs.scrapy.org/en/latest/topics/settings.html#download-delay # See also autothrottle settings and docs DOWNLOAD_DELAY = 1 # The download delay setting will honor only one of: #CONCURRENT_REQUESTS_PER_DOMAIN = 16 #CONCURRENT_REQUESTS_PER_IP = 16 # Disable cookies (enabled by default) #COOKIES_ENABLED = False # Disable Telnet Console (enabled by default) #TELNETCONSOLE_ENABLED = False # 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', #} # 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', 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36' } # Enable or disable spider middlewares # See https://docs.scrapy.org/en/latest/topics/spider-middleware.html #SPIDER_MIDDLEWARES = { # 'juzi.middlewares.JuziSpiderMiddleware': 543, #} # Enable or disable downloader middlewares # See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html #DOWNLOADER_MIDDLEWARES = { # 'juzi.middlewares.JuziDownloaderMiddleware': 543, #} # Enable or disable extensions # See https://docs.scrapy.org/en/latest/topics/extensions.html #EXTENSIONS = { # 'scrapy.extensions.telnet.TelnetConsole': None, #} # Configure item pipelines # See https://docs.scrapy.org/en/latest/topics/item-pipeline.html ITEM_PIPELINES = { 'juzi.pipelines.JuziPipeline': 300, } # Enable and configure the AutoThrottle extension (disabled by default) # See https://docs.scrapy.org/en/latest/topics/autothrottle.html #AUTOTHROTTLE_ENABLED = True # The initial download delay #AUTOTHROTTLE_START_DELAY = 5 # The maximum download delay to be set in case of high latencies #AUTOTHROTTLE_MAX_DELAY = 60 # The average number of requests Scrapy should be sending in parallel to # each remote server #AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0 # Enable showing throttling stats for every response received: #AUTOTHROTTLE_DEBUG = False # Enable and configure HTTP caching (disabled by default) # See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings #HTTPCACHE_ENABLED = True #HTTPCACHE_EXPIRATION_SECS = 0 #HTTPCACHE_DIR = 'httpcache' #HTTPCACHE_IGNORE_HTTP_CODES = [] #HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'

pipelines.py

# -*- coding: utf-8 -*- # Define your item pipelines here # # Don't forget to add your pipeline to the ITEM_PIPELINES setting # See: https://docs.scrapy.org/en/latest/topics/item-pipeline.html from scrapy.exporters import JsonLinesItemExporter class JuziPipeline(object): def __init__(self): # 初始化要领 # 使用二进制来写入，因此“w”-->"wb" self.fp = open("juzi.json", "wb") self.exporter = JsonLinesItemExporter(self.fp, ensure_ascii=False, encoding='utf-8') # self.exporter.start_exporting() def process_item(self, item, spider): self.exporter.export_item(item) return item def open_spider(self, spider): print("爬虫开始了！") def close_spider(self, spider): # self.exporter.finish_exporting() self.fp.close() print("爬虫结束了！")

scrapy爬虫框架(四)-爬取多个网页

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