爬去猫眼电影排行（待优化）

import requests
import re
import json
import time

def get_one_page(url):
    headers = {
        'User-Agent': 'Mozilla/5.0(Macintosh;Intel Mac OS X10_11_4) AppleWebKit/537.36(KHTML, '
                      'like Gecko) Chrome/52.0.2743.116 Safari/537.36'
    }
    response = requests.get(url, headers=headers)
    if response.status_code == 200:
        return response.text
    return None

def parse_one_page(html):
    pattern = re.compile(
        '<dd>.*?board-index.*?>(.*?)</i>.*?data-src="(.*?)".*?name.*?a.*?>(.*?)</a>.*?star.*?>(.*?)</p>.*?releasetime.*?>(.*?)</p>.*?integer.*?>(.*?)</i>.*?fraction.*?>(.*?)</i>.*?<dd>', re.S
    )
    items = re.findall(pattern, html)
    for item in items:
        ##yield 的作用就是把一个函数变成一个 generator
        yield {
            'index': item[0],
            'image': item[1],
            'title': item[2].strip(),
            'actor': item[3].strip()[3:] if len(item[3]) > 3 else '',
            'time':  item[4].strip()[5:] if len(item[4]) > 5 else '',
            'score': item[5].strip() + item[6].strip()
        }
#写入文件
def write_to_file(content):
    with open('result.txt', 'a', encoding='utf-8') as f:
        f.write(json.dumps(content, ensure_ascii=False) + '\n')

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__':
    for i in range(100):
        main(offset=i * 10)
        #防止速度过快，被封ip
        time.sleep(1)