python 小爬虫 python实现的一只从百度开始不断搜索的小爬虫

时间:2021-03-21 人气:0

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文中用到了BeautifulSoup这个库，目的是处理html文档分析的，因为我只是提取了title的关键字，所以可以用正则表达式代替，还有一个库是jieba，这个库是中文分词的作用，再有一个库是 chardet，用来判断字符的编码，本想多线程的，但是自认为被搞糊涂了，就放弃了

复制代码代码如下:

#coding:utf-8
import re
import urllib
import urllib2
import sys
import time
import Queue
import thread
import threading
import jieba
import chardet
from BeautifulSoup import BeautifulSoup as BS

DEEP = 1000
LOCK = threading.Lock()
PATH = "c:\\test\\"
urlQueue = Queue.Queue()
def pachong():
url = 'http://www.baidu.com'
return url

def getPageUrl(html):
reUrl = re.compile(r'<\s*[Aa]{1}\s+[^>]*?[Hh][Rr][Ee][Ff]\s*=\s*[\"\']?([^>\"\']+)[\"\']?.*?>')
urls = reUrl.findall(html)
for url in urls:
  if len(url) > 10:
   if url.find('javascript') == -1:
    urlQueue.put(url)

def getContents(url):
try:
  url = urllib2.quote(url.split('#')[0].encode('utf-8'), safe = "%/:=&?~#+!$,;'@()*[]")
  req = urllib2.urlopen(url)
  res = req.read()
  code = chardet.detect(res)['encoding']
  #print
  #print code
  res = res.decode(str(code), 'ignore')
  res = res.encode('gb2312', 'ignore')
  code = chardet.detect(res)['encoding']
  #print code
  #print res
  return res
except urllib2.HTTPError, e:
  print e.code
  return None
except urllib2.URLError, e:
  print str(e)
  return None

def writeToFile(html, url):
fp = file(PATH + str(time.time()) + '.html', 'w')
fp.write(html)
fp.close()

def getKeyWords(html):
code = chardet.detect(html)['encoding']
if code == 'ISO-8859-2':
  html.decode('gbk', 'ignore').encode('gb2312', 'ignore')
code = chardet.detect(html)['encoding']
soup = BS(html, fromEncoding="gb2312")
titleTag = soup.title
titleKeyWords = titleTag.contents[0]
cutWords(titleKeyWords)

def cutWords(contents):
print contents
res = jieba.cut_for_search(contents)
res = '\n'.join(res)
print res
res = res.encode('gb2312')
keyWords = file(PATH + 'cutKeyWors.txt', 'a')
keyWords.write(res)
keyWords.close()

def start():

while urlQueue.empty() == False:
  url = urlQueue.get()
  html = getContents(url)
  getPageUrl(html)
  getKeyWords(html)
  #writeToFile(html, url)

if __name__ == '__main__':
startUrl = pachong()
urlQueue.put(startUrl)
start()

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