python爬虫爬取豆瓣Top250的书籍信息，并保存到文件

import requests
from bs4 import BeautifulSoup

resp = requests.get('https://book.douban.com/top250?start=0')
soup = BeautifulSoup(resp.text, 'lxml')


# 发出请求获得HTML源码的函数
def get_html(url):
    # 伪装成浏览器访问
    headers = {
        'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36'}
    resp = requests.get(url, headers=headers).text

    return resp
# 获得所有页面的函数
def all_page():
    base_url = 'https://book.douban.com/top250?start='
    urllist = []
    # 从0到225，间隔25的数组
    for page in range(0, 250, 25):
        allurl = base_url + str(page)
        urllist.append(allurl)

    return urllist

# 解析页面，获得数据信息
def html_parse():
    # 调用函数，for循环迭代出所有页面
    for url in all_page():
        # BeautifulSoup的解析
        soup = BeautifulSoup(get_html(url), 'lxml')
        # 书名
        alldiv = soup.find_all('div', class_='pl2')
        names = [a.find('a')['title'] for a in alldiv]
        # 作者
        allp = soup.find_all('p', class_='pl')
        authors = [p.get_text() for p in allp]
        # 评分
        starspan = soup.find_all('span', class_='rating_nums')
        scores = [s.get_text() for s in starspan]
        # 简介
        sumspan = soup.find_all('span', class_='inq')
        sums = [i.get_text() for i in sumspan]
        for name, author, score, sum in zip(names, authors, scores, sums):
            name = '书名：' + str(name) + '\n'
            author = '作者：' + str(author) + '\n'
            score = '评分：' + str(score) + '\n'
            sum = '简介：' + str(sum) + '\n'
            data = name + author + score + sum
            # 保存数据
            f.writelines(data + '=======================' + '\n')



# 文件名
filename = '豆瓣图书Top250.txt'
# 保存文件操作
f = open(filename, 'w', encoding='utf-8')
# 调用函数
html_parse()
f.close()
print('保存成功。')





# find_all()方法，
# 注意class是Python关键词，后面要加下划线_：
# alldiv = soup.find_all('div', class_='pl2')
# for a in alldiv:
#     names = a.find('a')['title']
#     print('find_all():', names)

# find()方法：
# alldiv2 = soup.find('div', class_='pl2')
# names2 = alldiv2.find('a')['title']
# print('find():', names2 )