Python网页解析利器BeautifulSoup安装使用介绍

## filename: Grab.py
from BeautifulSoup import BeautifulSoup, Tag
import urllib2
import re
from Log import LOG

def LOG(*argv):
sys.stderr.write(*argv)
sys.stderr.write('\n')

class Grab():
url = ''
soup = None
def GetPage(self, url):
if url.find('http://',0,7) != 0:
url = 'http://' + url
self.url = url
LOG('input url is: %s' % self.url)
req = urllib2.Request(url, headers={'User-Agent' : "Magic Browser"})
try:
page = urllib2.urlopen(req)
except:
return
return page.read()

def ExtractInfo(self,buf):
if not self.soup:
try:
self.soup = BeautifulSoup(buf)
except:
LOG('soup failed in ExtractInfo :%s' % self.url)
return
try:
items = self.soup.findAll(attrs={'class':'item'})
except:
LOG('failed on find items:%s' % self.url)
return
links = []
objs = []
titles = []
scores = []
comments = []
intros = []
for item in items:
try:
pic = item.find(attrs={'class':'nbg'})
link = pic['href']
obj = pic.img['src']
info = item.find(attrs={'class':'pl2'})
title = re.sub('[ \t]+',' ',info.a.getText().replace(' ','').replace('\n',''))
star = info.find(attrs={'class':'star clearfix'})
score = star.find(attrs={'class':'rating_nums'}).getText().replace(' ','')
comment = star.find(attrs={'class':'pl'}).getText().replace(' ','')
intro = info.find(attrs={'class':'pl'}).getText().replace(' ','')
except Exception,e:
LOG('process error in ExtractInfo: %s' % self.url)
continue
links.append(link)
objs.append(obj)
titles.append(title)
scores.append(score)
comments.append(comment)
intros.append(intro)
return(links, objs, titles, scores, comments, intros)

def ExtractPageTurning(self,buf):
links = set([])
if not self.soup:
try:
self.soup = BeautifulSoup(buf)
except:
LOG('soup failed in ExtractPageTurning:%s' % self.url)
return
try:
pageturning = self.soup.find(attrs={'class':'paginator'})
a_nodes = pageturning.findAll('a')
for a_node in a_nodes:
href = a_node['href']
if href.find('http://',0,7) == -1:
href = self.url.split('?')[0] + href
links.add(href)
except:
LOG('get pageturning failed in ExtractPageTurning:%s' % self.url)

return links

def Destroy(self):
del self.soup
self.soup = None

接着我们再来写个测试样例