Python爬蟲框架Scrapy實(shí)例代碼

更新時(shí)間：2018年03月04日 10:24:19 作者：YangPython

這篇文章主要介紹了Python爬蟲框架Scrapy實(shí)例代碼,需要的朋友可以參考下

目標(biāo)任務(wù)：爬取騰訊社招信息，需要爬取的內(nèi)容為：職位名稱，職位的詳情鏈接，職位類別，招聘人數(shù)，工作地點(diǎn)，發(fā)布時(shí)間。

一、創(chuàng)建Scrapy項(xiàng)目

scrapy startproject Tencent

命令執(zhí)行后，會(huì)創(chuàng)建一個(gè)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(diǎn)
  workLocation = scrapy.Field()
  # 發(fā)布時(shí)間
  publishTime = scrapy.Field()

三、編寫spider文件

進(jìn)入Tencent目錄，使用命令創(chuàng)建一個(gè)基礎(chǔ)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(huì)在spiders文件夾中創(chuàng)建一個(gè)tencentPostion.py的文件，現(xiàn)在開始對(duì)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(duì)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(diǎn)
      item['workLocation'] = each.xpath("./td[4]/text()").extract()[0]
      # 發(fā)布時(shí)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(qǐng)求
    # self.offset自增10，同時(shí)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(shè)置（主要設(shè)置內(nèi)容）

# 設(shè)置請(qǐng)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(shè)置item——pipelines
ITEM_PIPELINES = {
  'tencent.pipelines.TencentPipeline': 300,
}

執(zhí)行命令，運(yùn)行程序

# tencentPosition為爬蟲名
scrapy crwal tencentPosition

使用CrawlSpider類改寫

# 創(chuàng)建項(xiàng)目
scrapy startproject TencentSpider
# 進(jìn)入項(xiàng)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(dǎo)入CrawlSpider類和Rule
from scrapy.spiders import CrawlSpider, Rule
# 導(dǎo)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(duì)象的列表
  pagelink = LinkExtractor(allow=("start=\d+"))
  rules = [
    # 獲取這個(gè)列表里的鏈接，依次發(fā)送請(qǐng)求，并且繼續(xù)跟進(jìn)，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(diǎn)
      item['workLocation'] = each.xpath("./td[4]/text()").extract()[0]
      # 發(fā)布時(shí)間
      item['publishTime'] = each.xpath("./td[5]/text()").extract()[0]
      yield item

總結(jié)

以上所述是小編給大家介紹的Python爬蟲框架Scrapy實(shí)例代碼，希望對(duì)大家有所幫助，如果大家有任何疑問歡迎給我留言，小編會(huì)及時(shí)回復(fù)大家的！

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