怎么在Python中使用Scrapy爬蟲框架?很多新手對此不是很清楚,為了幫助大家解決這個難題,下面小編將為大家詳細講解,有這方面需求的人可以來學習下,希望你能有所收獲。
創(chuàng)新互聯(lián)2013年至今,先為政和等服務建站,政和等地企業(yè),進行企業(yè)商務咨詢服務。為政和企業(yè)網(wǎng)站制作PC+手機+微官網(wǎng)三網(wǎng)同步一站式服務解決您的所有建站問題。一、創(chuàng)建Scrapy項目scrapy startproject Tencent
命令執(zhí)行后,會創(chuàng)建一個Tencent文件夾,結(jié)構(gòu)如下
二、編寫item文件,根據(jù)需要爬取的內(nèi)容定義爬取字段# -*- coding: utf-8 -*- import scrapy class TencentItem(scrapy.Item): # 職位名 positionname = scrapy.Field() # 詳情連接 positionlink = scrapy.Field() # 職位類別 positionType = scrapy.Field() # 招聘人數(shù) peopleNum = scrapy.Field() # 工作地點 workLocation = scrapy.Field() # 發(fā)布時間 publishTime = scrapy.Field()
三、編寫spider文件
進入Tencent目錄,使用命令創(chuàng)建一個基礎爬蟲類:
# tencentPostion為爬蟲名,tencent.com為爬蟲作用范圍 scrapy genspider tencentPostion "tencent.com"
執(zhí)行命令后會在spiders文件夾中創(chuàng)建一個tencentPostion.py的文件,現(xiàn)在開始對其編寫:
# -*- coding: utf-8 -*- import scrapy from tencent.items import TencentItem class TencentpositionSpider(scrapy.Spider): """ 功能:爬取騰訊社招信息 """ # 爬蟲名 name = "tencentPosition" # 爬蟲作用范圍 allowed_domains = ["tencent.com"] url = "http://hr.tencent.com/position.php?&start=" offset = 0 # 起始url start_urls = [url + str(offset)] def parse(self, response): for each in response.xpath("http://tr[@class='even'] | //tr[@class='odd']"): # 初始化模型對象 item = TencentItem() # 職位名稱 item['positionname'] = each.xpath("./td[1]/a/text()").extract()[0] # 詳情連接 item['positionlink'] = each.xpath("./td[1]/a/@href").extract()[0] # 職位類別 item['positionType'] = each.xpath("./td[2]/text()").extract()[0] # 招聘人數(shù) item['peopleNum'] = each.xpath("./td[3]/text()").extract()[0] # 工作地點 item['workLocation'] = each.xpath("./td[4]/text()").extract()[0] # 發(fā)布時間 item['publishTime'] = each.xpath("./td[5]/text()").extract()[0] yield item if self.offset < 1680: self.offset += 10 # 每次處理完一頁的數(shù)據(jù)之后,重新發(fā)送下一頁頁面請求 # self.offset自增10,同時拼接為新的url,并調(diào)用回調(diào)函數(shù)self.parse處理Response yield scrapy.Request(self.url + str(self.offset), callback = self.parse)
四、編寫pipelines文件
# -*- coding: utf-8 -*- import json class TencentPipeline(object): """ 功能:保存item數(shù)據(jù) """ def __init__(self): self.filename = open("tencent.json", "w") def process_item(self, item, spider): text = json.dumps(dict(item), ensure_ascii = False) + ",\n" self.filename.write(text.encode("utf-8")) return item def close_spider(self, spider): self.filename.close()
五、settings文件設置(主要設置內(nèi)容)
# 設置請求頭部,添加url DEFAULT_REQUEST_HEADERS = { "User-Agent" : "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0;", 'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' } # 設置item——pipelines ITEM_PIPELINES = { 'tencent.pipelines.TencentPipeline': 300, }
執(zhí)行命令,運行程序
# tencentPosition為爬蟲名 scrapy crwal tencentPosition
使用CrawlSpider類改寫
# 創(chuàng)建項目 scrapy startproject TencentSpider # 進入項目目錄下,創(chuàng)建爬蟲文件 scrapy genspider -t crawl tencent tencent.com item等文件寫法不變,主要是爬蟲文件的編寫 # -*- coding:utf-8 -*- import scrapy # 導入CrawlSpider類和Rule from scrapy.spiders import CrawlSpider, Rule # 導入鏈接規(guī)則匹配類,用來提取符合規(guī)則的連接 from scrapy.linkextractors import LinkExtractor from TencentSpider.items import TencentItem class TencentSpider(CrawlSpider): name = "tencent" allow_domains = ["hr.tencent.com"] start_urls = ["http://hr.tencent.com/position.php?&start=0#a"] # Response里鏈接的提取規(guī)則,返回的符合匹配規(guī)則的鏈接匹配對象的列表 pagelink = LinkExtractor(allow=("start=\d+")) rules = [ # 獲取這個列表里的鏈接,依次發(fā)送請求,并且繼續(xù)跟進,調(diào)用指定回調(diào)函數(shù)處理 Rule(pagelink, callback = "parseTencent", follow = True) ] # 指定的回調(diào)函數(shù) def parseTencent(self, response): for each in response.xpath("http://tr[@class='even'] | //tr[@class='odd']"): item = TencentItem() # 職位名稱 item['positionname'] = each.xpath("./td[1]/a/text()").extract()[0] # 詳情連接 item['positionlink'] = each.xpath("./td[1]/a/@href").extract()[0] # 職位類別 item['positionType'] = each.xpath("./td[2]/text()").extract()[0] # 招聘人數(shù) item['peopleNum'] = each.xpath("./td[3]/text()").extract()[0] # 工作地點 item['workLocation'] = each.xpath("./td[4]/text()").extract()[0] # 發(fā)布時間 item['publishTime'] = each.xpath("./td[5]/text()").extract()[0] yield item
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