使用python怎么定向爬虫校园论坛帖子，很多新手对此不是很清楚，为了帮助大家解决这个难题，下面小编将为大家详细讲解，有这方面需求的人可以来学习下，希望你能有所收获。
URLs.py
主要功能是根据一个初始url（包含page页面参数）来获得page页面从当前页面数到pageNum的url列表
import re def getURLs(url, attr, pageNum=1): all_links = [] try: now_page_number = int(re.search(attr+'=(\d+)', url, re.S).group(1)) for i in range(now_page_number, pageNum + 1): new_url = re.sub(attr+'=\d+', attr+'=%s' % i, url, re.S) all_links.append(new_url) return all_links except TypeError: print "arguments TypeError:attr should be string."
uni_2_native.py
由于论坛上爬取得到的网页上的中文都是unicode编码的形式，文本格式都为 &#XXXX;的形式，所以在爬得网站内容后还需要对其进行转换
import sys
import re
reload(sys)
sys.setdefaultencoding('utf-8')
def get_native(raw):
tostring = raw
while True:
obj = re.search('&#(.*?);', tostring, flags=re.S)
if obj is None:
break
else:
raw, code = obj.group(0), obj.group(1)
tostring = re.sub(raw, unichr(int(code)), tostring)
return tostring存入SQLite数据库：saveInfo.py
# -*- coding: utf-8 -*-
import MySQLdb
class saveSqlite():
def __init__(self):
self.infoList = []
def saveSingle(self, author=None, title=None, date=None, url=None,reply=0, view=0):
if author is None or title is None or date is None or url is None:
print "No info saved!"
else:
singleDict = {}
singleDict['author'] = author
singleDict['title'] = title
singleDict['date'] = date
singleDict['url'] = url
singleDict['reply'] = reply
singleDict['view'] = view
self.infoList.append(singleDict)
def toMySQL(self):
conn = MySQLdb.connect(host='localhost', user='root', passwd='', port=3306, db='db_name', charset='utf8')
cursor = conn.cursor()
# sql = "select * from info"
# n = cursor.execute(sql)
# for row in cursor.fetchall():
# for r in row:
# print r
# print '\n'
sql = "delete from info"
cursor.execute(sql)
conn.commit()
sql = "insert into info(title,author,url,date,reply,view) values (%s,%s,%s,%s,%s,%s)"
params = []
for each in self.infoList:
params.append((each['title'], each['author'], each['url'], each['date'], each['reply'], each['view']))
cursor.executemany(sql, params)
conn.commit()
cursor.close()
conn.close()
def show(self):
for each in self.infoList:
print "author: "+each['author']
print "title: "+each['title']
print "date: "+each['date']
print "url: "+each['url']
print "reply: "+str(each['reply'])
print "view: "+str(each['view'])
print '\n'
if __name__ == '__main__':
save = saveSqlite()
save.saveSingle('网','aaa','2008-10-10 10:10:10','www.baidu.com',1,1)
# save.show()
save.toMySQL()主要爬虫代码
import requests
from lxml import etree
from cc98 import uni_2_native, URLs, saveInfo
# 根据自己所需要爬的网站，伪造一个header
headers ={
'Accept': '',
'Accept-Encoding': '',
'Accept-Language': '',
'Connection': '',
'Cookie': '',
'Host': '',
'Referer': '',
'Upgrade-Insecure-Requests': '',
'User-Agent': ''
}
url = 'http://www.cc98.org/list.asp?boardid=459&page=1&action='
cc98 = 'http://www.cc98.org/'
print "get infomation from cc98..."
urls = URLs.getURLs(url, "page", 50)
savetools = saveInfo.saveSqlite()
for url in urls:
r = requests.get(url, headers=headers)
html = uni_2_native.get_native(r.text)
selector = etree.HTML(html)
content_tr_list = selector.xpath('//form/table[@class="tableborder1 list-topic-table"]/tbody/tr')
for each in content_tr_list:
href = each.xpath('./td[2]/a/@href')
if len(href) == 0:
continue
else:
# print len(href)
# not very well using for, though just one element in list
# but I don't know why I cannot get the data by index
for each_href in href:
link = cc98 + each_href
title_author_time = each.xpath('./td[2]/a/@title')
# print len(title_author_time)
for info in title_author_time:
info_split = info.split('\n')
title = info_split[0][1:len(info_split[0])-1]
author = info_split[1][3:]
date = info_split[2][3:]
hot = each.xpath('./td[4]/text()')
# print len(hot)
for hot_num in hot:
reply_view = hot_num.strip().split('/')
reply, view = reply_view[0], reply_view[1]
savetools.saveSingle(author=author, title=title, date=date, url=link, reply=reply, view=view)
print "All got! Now saving to Database..."
# savetools.show()
savetools.toMySQL()
print "ALL CLEAR! Have Fun!"看完上述内容是否对您有帮助呢？如果还想对相关知识有进一步的了解或阅读更多相关文章，请关注创新互联成都网站设计公司行业资讯频道，感谢您对创新互联成都网站设计公司的支持。
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