Python爬虫之爬取豆瓣top

import bs4          # 网页解析,获取数据
import re           # 正则表达式,进行文字匹配
import urllib.request       # 制定URL,获取网页数据
import urllib.parse
import xlwt         # 进行Excel操作
import sqlite3      # 进行SQLite数据库操作
import time
import ssl
ssl._create_default_https_context = ssl._create_unverified_context


def main():
    baseurl = "https://movie.douban.com/top250?start="
    # proxy_support = urllib.request.ProxyHandler({'http': random.choice(proxy_list)})
    # askURL("https://movie.douban.com/top250?start=0")
    # 1.爬取网页
    datalist = getData(baseurl)
    savepath = "豆瓣电影Top250.xls"
    dbpath = "movies.db"
    # # 3.保存数据
    #saveData(datalist, savepath)
    saveDataDB(datalist, dbpath)


# 影片信息的链接规则
findLink = re.compile(r'<a href="(.*?)">')     # 创建正则表达式的对象,表示规则(字符串的模式)
# 影片图片的链接规则
findImgSrc = re.compile(r'img.*src="(.*?)"', re.S)      # re.S让换行符包含在字符中
# 影片的片名
findTitle = re.compile(r'<span class="title">(.*)</span>')
# 影片评分
findRating = re.compile(r'<span class="rating_num" property="v:average">(.*)</span>')
# 评价人数
findJudge = re.compile(r'<span>(\d*)人评价</span>')
# 概况
findInq = re.compile(r'<span class="inq">(.*)</span>')
# 影片的相关内容
findBd = re.compile(r'<p class="">(.*?)</p>', re.S)


# 爬取网页
def getData(baseurl):
    dataList = []

    for i in range(0, 10):
        url = baseurl + str(i * 25)
        html = askURL(url)
        # 逐一解析数据
        soup = bs4.BeautifulSoup(html, "html.parser")   # 以html.parser形式解析html文档
        for item in soup.find_all('div', class_="item"):    # 查找符合要求的字符串,形成列表
            data = []   # 保存一部电影的所有信息
            item = str(item)

            # 影片详情的链接
            link = re.findall(findLink, item)[0]     # re库用来通过正则表达式查找指定的字符串
            data.append(link)

            imgSrc = re.findall(findImgSrc, item)[0]
            data.append(imgSrc)
            titles = re.findall(findTitle, item)
            if len(titles) == 2:
                ctitle = titles[0]      # 添加中文名
                data.append(ctitle)
                etitle = titles[1].replace("/", "")
                data.append(etitle)     # 添加外名
            else:
                data.append(titles[0])
                data.append(' ')    # 外名留空

            rating = re.findall(findRating, item)
            r = rating[0]
            data.append(r)     # 添加评分

            judgeNum = re.findall(findJudge, item)
            j = judgeNum[0]
            data.append(j)   # 添加评价人数

            inq = re.findall(findInq,item)      # 添加概述
            if len(inq) != 0:
                inq = inq[0].replace("。", "")
                data.append(inq)
            else:
                data.append(" ")    # 留空

            bd = re.findall(findBd, item)[0]       # 添加简介
            bd = re.sub('<br(\s+)?/>(\s+)?', ' ', bd)
            data.append(bd.strip())     # bd.strip()去掉空格
            dataList.append(data)       # 把处理好的一部电影信息放入dataList中

    return dataList


# 得到指定一个URL的网页信息
def askURL(url):
    time.sleep(0.1)
    # 用户代理,表示告诉要访问的URL我们是一个什么类型的机器-浏览器(本质上是告诉浏览器我们可以接收什么水平的文件内容)
    # 模拟浏览器头部信息,向我们要访问的服务器发送消息
    # 随机从列表中选择IP、Header
    head = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.93 Safari/537.36"
    }
    request = urllib.request.Request(url=url, headers=head)
    html = ""
    try:
        response = urllib.request.urlopen(request)
        html = response.read().decode("utf-8")
    except Exception as result:
        print(result)
    return html

# 保存数据
def saveData(datalist, savepath):
    print("save……")
    book = xlwt.Workbook(encoding='utf-8')
    sheet = book.add_sheet('豆瓣电影Top250', cell_overwrite_ok=True)
    col = ("电影详情链接", "图片链接", "影片中文名", "影片海外名", "评分", "评价数", "概况", "相关信息")
    for i in range(0, 8):
        sheet.write(0, i, col[i])
    for i in range(0, 250):
        print("第%d条" % (i+1))
        data = datalist[i]
        for j in range(0, 8):
            sheet.write(i+1, j, data[j])    # 写入数据
    book.save(savepath)  # 保存


def saveDataDB(datalist, dbpath):
    init_db(dbpath)
    conn = sqlite3.connect(dbpath)
    cur = conn.cursor()
    for data in datalist:
        for index in range(len(data)):
            if index == 4 or index == 5:
                continue
            data[index] = '"'+data[index]+'"'
        sql = '''
            insert into movie250(
            info_link,pic_link,cname,ename,scroe,rated,instroduction,info)
            values(%s)''' % (",".join(data))
        cur.execute(sql)
        conn.commit()
    cur.close()
    conn.close()



def init_db(dbpath):
    sql = '''
        create table movie250
        (
        id integer primary key autoincrement,
        info_link text,
        pic_link text,
        cname varchar,
        ename varchar,
        scroe text,
        rated text,
        instroduction text,
        info text
        );
    '''    # 创建数据表
    conn = sqlite3.connect(dbpath)
    cursor = conn.cursor()
    cursor.execute(sql)
    conn.commit()
    conn.close()


if __name__ == "__main__":
    main()
    # init_db('test.db')
    print("爬取完毕")