python requests爬虫

1、介绍

requests是爬虫的利器，可以设置代理ip，cookies，headers等多种反爬虫手段，过滤数据笨的办法可以使用正则，比较可靠稳定的办法使用xpath，找了一个爬虫腾讯招聘的code简要说下

2、代码

• 设置tr标签的属性值：tr[@class='c bottomline']
• td[1] 表示第一个td标签
• .// ： 表示选取当前节点开始匹配，直到匹配到符合条件的

# -*- coding: utf-8 -*-

from lxml import etree
import requests

BASE_DOMAIN="http://hr.tencent.com/"
HEADERS = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) '
                  'AppleWebKit/537.36 (KHTML, like Gecko)'
                  ' Chrome/67.0.3396.99 Safari/537.36'
}

BASE_URL="https://hr.tencent.com/position.php?keywords=python&lid=0&tid=0&start=0"


def parse_detail_page(url):
    position={}
    response=requests.get(url,headers=HEADERS)
    html=etree.HTML(response.text)
    work_name=html.xpath("//tr[@class='h']/td/text()")[0]
    work_place=html.xpath("//tr[@class='c bottomline']/td[1]/text()")[0]
    work_category=html.xpath("//tr[@class='c bottomline']/td[2]/text()")[0]
    work_lack_number=html.xpath("//tr[@class='c bottomline']/td[3]/text()")[0]
    more_infos=html.xpath("//ul[@class='squareli']")
    work_duty=more_infos[0].xpath(".//text()")
    work_require=more_infos[1].xpath(".//text()")

    position['work_name']=work_name
    position['work_place']=work_place
    position['work_category']=work_category
    position['work_lack_number']=work_lack_number
    position['work_duty']=work_duty
    position['work_require']=work_require

    return position

def get_detail_urls(url):
    response=requests.get(url=BASE_URL,headers=HEADERS)
    text=response.text
    html=etree.HTML(text)
    links=html.xpath("//tr[@class='even']//a/@href")
    links=map(lambda url:BASE_DOMAIN+url,links)
    return links


def spider():
    base_url="https://hr.tencent.com/position.php?keywords=python&lid=0&tid=0&start={}#a"
    positions=[]
    for x in range(0, 4): #43
        x*=10
        url=base_url.format(x)
        detail_urls=get_detail_urls(url)
        for detail_url in detail_urls:
            position=parse_detail_page(detail_url)
            positions.append(position)
            with open('tecentRecruit.txt','a',encoding='utf-8') as f:
                for (key,value) in position.items():
                    if(key=='work_duty'):
                        str='work_duty :{}'
                        f.write(str.format(value))
                        f.write('\n')
                    elif(key=='work_require'):
                        str="work_require :{}"
                        f.write(str.format(value))
                        f.write('\n')
                    else:
                        f.write(key+":"+value)
                        f.write('\n')
                f.write('\n'*3)


if __name__ == '__main__':
    spider()

 lxml中xpath的使用详细讲解

Xpath语法详细讲解