爬虫练习——爬取豆瓣前250电影信息

# -*- codeing = utf-8 -*-
# @Time : 2020/7/9 16:43
# @Author: 小菜菜最菜
# @File : douban.py
# @Software : PyCharm

from bs4 import BeautifulSoup# 网页解析，获取数据
import re # 正则表达式，进行文字匹配
import urllib.request,urllib.error  # 指定URL，获取网页数据
import xlwt # 进行excel操作
import sqlite3 # 进行SQLite数据库操作

def main():
    baseurl = "https://movie.douban.com/top250?start="
    # 1. 爬取网页
    datalist = getData(baseurl)   
    savepath = "豆瓣电影Top250.xls"  # 本地excel保存
    dbpath = "movie.db"             # sqlite数据库保存
    
    saveData2DB(datalist,dbpath)

    saveData(datalist,savepath)


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



# 爬取网页  一般是边爬取边解析
def getData(baseurl):
    datalist = []
    for i in range(0,10):   # 调用获取页面信息的函数10次
        url = baseurl + str(i*25)
        html = askURL(url)  # 保存获取到的网页源码

        # 2. 逐一解析数据

        soup = BeautifulSoup(html, "html.parser")
        for item in soup.find_all('div',class_="item"):  # 查找符合要求的字符串，形成列表
           #print(item)   #测试：查看电影item的全部信息
            data = []  # 保存一部电影的所有信息
            item = str(item)
            # 影片详情的连接
            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)

            title = re.findall(findTitle,item)   # 片名可能只有一个中文名
            if len(title) == 2:
                ctitle = title[0]
                data.append(ctitle)   # 添加中文名
                otitle = title[1].replace("/","")
                data.append(otitle)   # 添加外国名
            else:
                data.append(title[0])
                data.append(' ')   # 外国名留空

            rating = re.findall(findRating,item)[0]
            data.append(rating)

            judgeNum = re.findall(findJudge,item)[0]
            data.append(judgeNum)

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

            bd = re.findall(findBd, item)[0]
            bd = re.sub('<br(\s+)?/>(\s+)?', " ", bd)  # 去掉<br/>
            bd = re.sub('/', " ", bd)  # 替换/
            data.append(bd.strip())  # 去掉前后的空格

            datalist.append(data)  # 把处理好的一部电影信息放入datalist
    print(datalist)
    return datalist



# 得到一个指定URL的网页内容
def askURL(url):
    head = {  # 模拟浏览器头部信息，向豆瓣服务器发送消息
        "User-Agent": "Mozilla / 5.0(Windows NT 10.0; Win64; x64) AppleWebKit / 537.36(KHTML, like Gecko) Chrome / 80.0.3987.122  Safari / 537.36"
    }
        # 用户代理：表示告诉豆瓣服务器，我们是什么类型的机器，浏览器（本质上是告诉浏览器，我们可以接受什么水平的
    request = urllib.request.Request(url,headers=head)
    html = ""
    try:
        response = urllib.request.urlopen(request)
        html = response.read().decode("utf-8")
        #print(html)
    except urllib.error.URLError as e:
        if hasattr(e,"code"):
            print(e.code)
        if hasattr(e,"reason"):
            print(e.reason)
    return html



# 3. 保存数据
def saveData(datalist,savepath):
    print('save...')
    book = xlwt.Workbook(encoding="utf-8",style_compression=0)
    sheet = book.add_sheet('豆瓣电影Top250',cell_overwrite_ok=True)
    col = ("电影详情连接","图片连接","影片中文名","影片外国名","评分","评价数","概括","相关信息")
    for i in range(len(col)):
        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])
    book.save(savepath)

def init_db(dbpath):
    sql = '''
            create table movie250 
            (
            id integer primary key autoincrement,
            info_link text,
            pic_link text,
            cname varchar,
            ename varchar,
            score numeric ,
            rated numeric ,
            instroduction text,
            info text
            )

        '''  # 创建数据表
    conn = sqlite3.connect(dbpath)
    cursor = conn.cursor()
    cursor.execute(sql)
    conn.commit()
    conn.close()

def saveData2DB(datalist,dbpath):
    init_db(dbpath)
    conn = sqlite3.connect(dbpath)
    cur = conn.cursor()

    for data in datalist:
        for index in range(len(data)):
            data[index] = '"' + data[index] + '"'

        sql = '''
                insert into movie250 (
                info_link,pic_link,cname,ename,score,rated,instroduction,info) 
                values(%s)''' % ",".join(data)
        cur.execute(sql)
        conn.commit()
    cur.close()
    conn.close()
    print("...")
if __name__ == "__main__":  # 当程序执行时
    # 调用函数
    main()
    print("ending....")