爬虫实战1：使用requests和正则爬取电影信息

代码如下

 # coding=utf-8
 import requests
 from requests.exceptions import RequestException
 import re
 import json
 from multiprocessing import Pool  #引入进程池

 def get_one_page(url):
     headers = {
         'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) '
                       'Chrome/65.0.3325.181 Safari/537.36'
     }
     try:
         response = requests.get(url, headers=headers)
         if response.status_code == 200:
             return response.text
         return None
     except RequestException:
         return None

 def parse_one_page(html):
     #得到排名，简报，标题，主演,上映时间，分数
     pattern = re.compile('<dd>.*?board-index.*?>(\d+)</i>.*?data-src="(.*?)".*?name"><a.*?>(.*?)</a>'
                          '.*?star">(.*?)</p>.*?releasetime">(.*?)</p>'
                          '.*?integer">(.*?)</i>.*?fraction">(.*?)</i>.*?</dd>', re.S)

     items = re.findall(pattern, html)

     #对输出内容进行格式化,将原先的元组格式转化为字典
     for item in items:
         yield {
             'index': item[0],
             'image': item[1],
             'title': item[2],
             'actor': item[3].strip()[3:],
             'time': item[4].strip()[5:],
             'score': item[5]+item[6]
         }

 #json.dumps方法将字典转变为字符串
 #encoding和下面的ascii如果不写的话resul.txt文件内容为乱码
 def write_to_file(content):
     with open('result.txt', 'a', encoding='utf-8') as f:
         f.write(json.dumps(content, ensure_ascii=False) + '\n')
         f.close()

 #offset用来表示不同页面
 def main(offset):
     url = 'http://maoyan.com/board/4?offset=' + str(offset)
     html = get_one_page(url)
     for item in parse_one_page(html):
         print(item)
         write_to_file(item)

 if __name__ == '__main__':
     '''
     抓取top100的影片信息的一般方法，i*10的原因是网址上每页offset是按10的倍数变化的
     for i in range(10):
         main(i*10)
 '''
     #使用进程池提高效率
     pool = Pool()
     pool.map(main, [i*10 for i in range(10)])

使用pyquery简单实现

from pyquery import PyQuery as pq

headers={ 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36'}

def write_to_file(content):
    with open('result.txt', 'a') as f:
        f.write(content)

def main(offset):
    url='http://maoyan.com/board/4?offset=' + str(offset)
    doc=pq(url, headers=headers)

    dd=doc('dd').text()
    for x in dd.split(" "):
        print(x)
        print('\n')
        write_to_file(x + '\n')
        """
        合些的话可以如下        
        c=''.join([x, '\n'])
        print(c)
        """
 
if __name__ == '__main__':
    for i in range(10):
        main(i*10)