import requests
from requests.exceptions import RequestException
from fake_useragent import UserAgent
import re
import json
import time

def get_one_page(url):
    """
    发送请求，获取响应！
    :param url:
    :return:
    """
    try:
        headers = {
            'User-Agent':UserAgent().random
        }
        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):
    """
    利用正则表达式提取响应里的电影信息，并形成结构化数据！
    :param html:
    :return:
    """
    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 {
            '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()
        }

def write_to_file(content):
    """
    存储数据，通过JSON库的dumps()方法实现字典的序列化，写入到一个文本文件！
    :param content:
    :return:
    """
    with open('result.txt', 'a', encoding='utf-8') as f:
        f.write(json.dumps(content, ensure_ascii=False) + ',\n')

def main(offset):
    """
    通过构造URL中的offset参数（偏移量值），实现TOP100十页数据的爬取！
    :param offset:
    :return:
    """
    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(10):
        main(offset=i * 10)
        time.sleep(1)

3.关于正则表达式匹配电影信息规则编写参考网页源码，举例如下：

                <dd>
                        <i class="board-index board-index-1">1</i>
    <a href="/films/1200486" title="我不是药神" class="image-link" data-act="boarditem-click" data-val="{movieId:1200486}">
      <img src="//s3plus.meituan.net/v1/mss_e2821d7f0cfe4ac1bf9202ecf9590e67/cdn-prod/file:5788b470/image/loading_2.e3d934bf.png" alt="" class="poster-default" />
      <img data-src="https://p0.meituan.net/movie/414176cfa3fea8bed9b579e9f42766b9686649.jpg@160w_220h_1e_1c" alt="我不是药神" class="board-img" />
    </a>
    <div class="board-item-main">
      <div class="board-item-content">
              <div class="movie-item-info">
        <p class="name"><a href="/films/1200486" title="我不是药神" data-act="boarditem-click" data-val="{movieId:1200486}">我不是药神</a></p>
        <p class="star">
                主演：徐峥,周一围,王传君
        </p>
<p class="releasetime">上映时间：2018-07-05</p>    </div>
    <div class="movie-item-number score-num">
<p class="score"><i class="integer">9.</i><i class="fraction">6</i></p>        
    </div>

      </div>
    </div>

                </dd>

{"index": "1", "image": "https://p0.meituan.net/movie/414176cfa3fea8bed9b579e9f42766b9686649.jpg@160w_220h_1e_1c", "title": "我不是药神", "actor": "徐峥,周一围,王传君", "time": "2018-07-05", "score": "9.6"},
{"index": "2", "image": "https://p0.meituan.net/movie/8112a8345d7f1d807d026282f2371008602126.jpg@160w_220h_1e_1c", "title": "肖申克的救赎", "actor": "蒂姆·罗宾斯,摩根·弗里曼,鲍勃·冈顿", "time": "1994-09-10(加拿大)", "score": "9.5"},
{"index": "3", "image": "https://p1.meituan.net/movie/c9b280de01549fcb71913edec05880585769972.jpg@160w_220h_1e_1c", "title": "绿皮书", "actor": "维果·莫腾森,马赫沙拉·阿里,琳达·卡德里尼", "time": "2019-03-01", "score": "9.5"},
{"index": "4", "image": "https://p1.meituan.net/movie/ac8f0004928fbce5a038a007b7c73cec746794.jpg@160w_220h_1e_1c", "title": "小偷家族", "actor": "中川雅也,安藤樱,松冈茉优", "time": "2018-08-03", "score": "8.1"},
{"index": "5", "image": "https://p0.meituan.net/movie/609e45bd40346eb8b927381be8fb27a61760914.jpg@160w_220h_1e_1c", "title": "海上钢琴师", "actor": "蒂姆·罗斯,比尔·努恩,克兰伦斯·威廉姆斯三世", "time": "2019-11-15", "score": "9.3"},
{"index": "6", "image": "https://p0.meituan.net/movie/005955214d5b3e50c910d7a511b0cb571445301.jpg@160w_220h_1e_1c", "title": "哪吒之魔童降世", "actor": "吕艳婷,囧森瑟夫,瀚墨", "time": "2019-07-26", "score": "9.6"},
{"index": "7", "image": "https://p0.meituan.net/movie/61fea77024f83b3700603f6af93bf690585789.jpg@160w_220h_1e_1c", "title": "霸王别姬", "actor": "张国荣,张丰毅,巩俐", "time": "1993-07-26", "score": "9.5"},
{"index": "8", "image": "https://p1.meituan.net/movie/580d81a2c78bf204f45323ddb4244b6c6821175.jpg@160w_220h_1e_1c", "title": "美丽人生", "actor": "罗伯托·贝尼尼,朱斯蒂诺·杜拉诺,赛尔乔·比尼·布斯特里克", "time": "2020-01-03", "score": "9.3"},
{