Python爬虫（1）——基于BeautifulSoup爬取豆瓣电影信息

本文主要用BeautifulSoup来爬取豆瓣Top电影信息。软件环境基于Anaconda3+python3.5
具体代码如下所示：

# -*- coding: utf-8 -*-
"""
Created on Sun Mar 26 21:37:18 2017

@author: zch
"""

import urllib.request  
import re   
from bs4 import BeautifulSoup  
import codecs  

#爬虫函数 
def crawl(url):  
    page = urllib.request.urlopen(url)   
    contents = page.read()   
    soup = BeautifulSoup(contents, "html.parser")   
print (u'豆瓣电影250: 序号 \t影片名\t 评分 \t评价人数') 
    infofile.write(u"豆瓣电影250: 序号 \t影片名\t 评分 \t评价人数\r\n")  
print (u'爬取信息如下:\n')  
for tag in soup.find_all(attrs={"class":"item"}):  
#print tag 
#爬取序号 
        num = tag.find('em').get_text()  
print (num)     
#爬取电影名称 
        name = tag.find(attrs={"class":"hd"}).a.get_text()  
        name = name.replace('\n',' ')  
print (name)  
        infofile.write(num+" "+name+"\r\n")  
#电影名称 
        title = tag.find_all(attrs={"class":"title"})  
        i = 0  
for n in title:  
            text = n.get_text()  
            text = text.replace('/','')  
            text = text.lstrip()  
if i==0:  
print (u'[中文标题]', text)  
                infofile.write(u"[中文标题]" + text + "\r\n")  
elif i==1:  
print (u'[英文标题]', text)  
                infofile.write(u"[英文标题]" + text + "\r\n")  
            i = i + 1  
#爬取评分和评论数 
        info = tag.find(attrs={"class":"star"}).get_text()  
        info = info.replace('\n',' ')  
        info = info.lstrip()  
print (info)  
        mode = re.compile(r'\d+\.?\d*')  
print (mode.findall(info))  
        i = 0  
for n in mode.findall(info):  
if i==0:  
print (u'[分数]', n)  
                infofile.write(u"[分数]" + n + "\r\n")  
elif i==1:  
print (u'[评论]', n)  
                infofile.write(u"[评论]" + n + "\r\n")  
            i = i + 1  
#获取评语 
        info = tag.find(attrs={"class":"inq"})  
if(info): # 132部电影 [消失的爱人] 没有影评 
            content = info.get_text()  
print (u'[影评]',content) 
            infofile.write(u"[影评]" + content + "\r\n")  
print ('')  


#主函数 
if __name__ == '__main__':  

    infofile = codecs.open("Result_Douban.txt", 'a', 'utf-8')       
    url = 'http://movie.douban.com/top250?format=text'  
    i = 0  
while i<10:  
print (u'页码', (i+1))  
        num = i*25 #每次显示25部 URL序号按25增加 
        url = 'https://movie.douban.com/top250?start=' + str(num) + '&filter='  
        crawl(url)  
        infofile.write("\r\n\r\n\r\n")  
        i = i + 1  
    infofile.close()  

爬取的豆瓣电影信息都存储在文本文件中，以供后续分析，如下图所示：