python爬虫1——获取网站源代码(豆瓣图书top250信息)

# -*- coding: utf-8 -*-
import requests
import re
import sys
reload(sys)
sys.setdefaultencoding('utf-8')

class Spider(object):
    def __init__(self):
        print('开始爬取豆瓣图书top250的内容。。。。。。')

    # 传入url，返回网页源代码
    def getSourceCode(self, url):
        html = requests.get(url)
        return html.text

    # 从源代码中提取出我们需要的内容块：{书名、作者出版社等、评分、评价人数}。
    def getEveryBookContent(self, sourceCode):
        everyBookContent = re.findall('<table width="100%">(.*?)</table>', sourceCode, re.S)
        # everyBookContent = re.findall('<div class="pl2">(.*?)</div>(.*?)<p class="pl">(.*?)</p>', sourceCode, re.S)
        return everyBookContent

    # 从内容块中提取出数据
    def getBookInfo(self, eachBookContent):
        bookInfo = {}
        # bookInfo['title'] = re.subn('( |\n|<br/>|</?span.*?>)', "", re.search('<a href=.*?>(.*?)</a>', eachBookContent, re.S).group(1))[0]
        bookInfo['title'] = re.sub('( |\n|<br/>|</?span.*?>)', "", re.search('<a href=.*?>(.*?)</a>', eachBookContent, re.S).group(1))
        bookInfo['author'] = re.search('<p class="pl">(.*?)</p>', eachBookContent, re.S).group(1)
        bookInfo['discussNum'] = re.sub('( |\n|<br/>)', "", re.search('<span class="pl">\((.*?)\)</span>', eachBookContent, re.S).group(1))
        bookInfo['score'] = re.search('<span class="rating_nums">(.*?)</span>', eachBookContent, re.S).group(1)
        return bookInfo

    # 将结果保存到文件
    def saveBookInfo(self, bookList):
        f = open("bookList.txt", "a")
        for each in bookList:
            f.writelines('书  名:\t {}\n'.format(each['title']))
            f.writelines('作  者:\t {}\n'.format(each['author']))
            f.writelines('评论数:\t {}\n'.format(each['discussNum']))
            f.writelines('评  分:\t {}\n\n'.format(each['score']))
        f.close()

    def start(self, url):
        sourceCode = self.getSourceCode(url)
        everyBookContent = self.getEveryBookContent(sourceCode)
        bookList = []
        for each in everyBookContent:
            bookList.append(self.getBookInfo(each))
        self.saveBookInfo(bookList)


if __name__ == '__main__':
    douban = Spider()
    url = 'http://book.douban.com/top250?start=0'
    i = 0
    while i <= 225:
        url = 'http://book.douban.com/top250?start={}'.format(i)
        douban.start(url)
        i += 25