python 案例：使用BeautifuSoup4的爬虫

我们以腾讯社招页面来做演示：http://hr.tencent.com/position.php?&start=10#a

使用BeautifuSoup4解析器，将招聘网页上的职位名称、职位类别、招聘人数、工作地点、发布时间，以及每个职位详情的点击链接存储出来。

# bs4_tencent.py

from bs4 import BeautifulSoup
import urllib2
import urllib
import json    # 使用了json格式存储

def tencent():
    url = 'http://hr.tencent.com/'
    request = urllib2.Request(url + 'position.php?&start=10#a')
    response =urllib2.urlopen(request)
    resHtml = response.read()

    output =open('tencent.json','w')

    html = BeautifulSoup(resHtml,'lxml')

# 创建CSS选择器
    result = html.select('tr[class="even"]')
    result2 = html.select('tr[class="odd"]')
    result += result2

    items = []
    for site in result:
        item = {}

        name = site.select('td a')[0].get_text()
        detailLink = site.select('td a')[0].attrs['href']
        catalog = site.select('td')[1].get_text()
        recruitNumber = site.select('td')[2].get_text()
        workLocation = site.select('td')[3].get_text()
        publishTime = site.select('td')[4].get_text()

        item['name'] = name
        item['detailLink'] = url + detailLink
        item['catalog'] = catalog
        item['recruitNumber'] = recruitNumber
        item['publishTime'] = publishTime

        items.append(item)

    # 禁用ascii编码，按utf-8编码
    line = json.dumps(items,ensure_ascii=False)

    output.write(line.encode('utf-8'))
    output.close()

if __name__ == "__main__":
   tencent()