python爬虫学习，爬取豆瓣各分类书单

pachon2.5.py      
# -- coding: utf-8 --
import urllib
import urllib2
import re
import sys

reload(sys)

sys.setdefaultencoding('utf-8')

class book:     #豆瓣书籍的类
    def init(self, types, page):
        self.baseUrl = 'http://www.douban.com/tag/'
        self.types = types
        self.filename = 'doubanbook.txt'
        self.page = page

def getContents(self): #爬取源代码
    try:
        #if self.page == 0:
        url = self.baseUrl + self.types + '/book'
        #else:
        #   url = self.baseUrl + self.types + '/book?start=' + str(self.page)
        user_agent = 'Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.65 Safari/537.36'
        headers = { 'User-Agent' : user_agent}
        request = urllib2.Request(url,headers = headers)
        response = urllib2.urlopen(request)
        content = response.read()  #.decode('utf-8')
        pattern = re.compile('<a href=.*?class="title".*?target="_blank">(.*?)</a>.*?>(.*?)</div>',re.S)
        items = re.findall(pattern,content)
        return items
    except urllib2.URLError, e:
        if hasattr(e, "reason"):
            print u"豆瓣链接错误，错误原因", e.reason
            return None

def writetext(self, items): #写入txt
    for item in items:
        print item[0],item[1]
        files = open(self.filename,'a')
        files.write(item[0])
        files.write(item[1])
        files.write('\n')
        files.close()

def strat(self): #启动函数
    self.writetext(self.getContents())
    print u"""出现乱码为正常现象，在与本脚本相同的文件夹下会多出一个,
    
    doubanbook.txt的文件里面有所爬书籍，如你把本脚本放在桌面,
文件便会出现在桌面"""
        print u"结束输入 'O' , 联系作者输入 'A'"
        end = raw_input('>')
        if end == 'A':
            print u"QQ邮箱:1021644861@qq.com"
            raw_input('>')
        else:
            print "over"