Python はマルチスレッドを使用して Web ページ情報をクロールします

'''
Created on 2012-3-13
Get Page using GET method
Default using HTTP Protocol , http port 80
@author: xiaojay
'''
import socket
import statistics
import datetime
import threading
socket.setdefaulttimeout(statistics.timeout)
class Error404(Exception):
  '''Can not find the page.'''
  pass
class ErrorOther(Exception):
  '''Some other exception'''
  def __init__(self,code):
    #print 'Code :',code
    pass
class ErrorTryTooManyTimes(Exception):
  '''try too many times'''
  pass
def downPage(hostname ,filename , trytimes=0):
  try :
    #To avoid too many tries .Try times can not be more than max_try_times
    if trytimes >= statistics.max_try_times :
      raise ErrorTryTooManyTimes
  except ErrorTryTooManyTimes :
    return statistics.RESULTTRYTOOMANY,hostname+filename
  try:
    s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    #DNS cache
    if statistics.DNSCache.has_key(hostname):
      addr = statistics.DNSCache[hostname]
    else:
      addr = socket.gethostbyname(hostname)
      statistics.DNSCache[hostname] = addr
    #connect to http server ,default port 80
    s.connect((addr,80))
    msg = 'GET '+filename+' HTTP/1.0\r\n'
    msg += 'Host: '+hostname+'\r\n'
    msg += 'User-Agent:xiaojay\r\n\r\n'
    code = ''
    f = None
    s.sendall(msg)
    first = True
    while True:
      msg = s.recv(40960)
      if not len(msg):
        if f!=None:
          f.flush()
          f.close()
        break
      # Head information must be in the first recv buffer
      if first:
        first = False
        headpos = msg.index("\r\n\r\n")
        code,other = dealwithHead(msg[:headpos])
        if code=='200':
          #statistics.fetched_url += 1
          f = open('pages/'+str(abs(hash(hostname+filename))),'w')
          f.writelines(msg[headpos+4:])
        elif code=='301' or code=='302':
          #if code is 301 or 302 , try down again using redirect location
          if other.startswith("http") :
            hname, fname = parse(other)
            downPage(hname,fname,trytimes+1)#try again
          else :
            downPage(hostname,other,trytimes+1)
        elif code=='404':
          raise Error404
        else :
          raise ErrorOther(code)
      else:
        if f!=None :f.writelines(msg)
    s.shutdown(socket.SHUT_RDWR)
    s.close()
    return statistics.RESULTFETCHED,hostname+filename
  except Error404 :
    return statistics.RESULTCANNOTFIND,hostname+filename
  except ErrorOther:
    return statistics.RESULTOTHER,hostname+filename
  except socket.timeout:
    return statistics.RESULTTIMEOUT,hostname+filename
  except Exception, e:
    return statistics.RESULTOTHER,hostname+filename
def dealwithHead(head):
  '''deal with HTTP HEAD'''
  lines = head.splitlines()
  fstline = lines[0]
  code =fstline.split()[1]
  if code == '404' : return (code,None)
  if code == '200' : return (code,None)
  if code == '301' or code == '302' :
    for line in lines[1:]:
      p = line.index(':')
      key = line[:p]
      if key=='Location' :
        return (code,line[p+2:])
  return (code,None)
def parse(url):
  '''Parse a url to hostname+filename'''
  try:
    u = url.strip().strip('\n').strip('\r').strip('\t')
    if u.startswith('http://') :
      u = u[7:]
    elif u.startswith('https://'):
      u = u[8:]
    if u.find(':80')>0 :
      p = u.index(':80')
      p2 = p + 3
    else:
      if u.find('/')>0:
        p = u.index('/')
        p2 = p
      else:
        p = len(u)
        p2 = -1
    hostname = u[:p]
    if p2>0 :
      filename = u[p2:]
    else : filename = '/'
    return hostname, filename
  except Exception ,e:
    print "Parse wrong : " , url
    print e
def PrintDNSCache():
  '''print DNS dict'''
  n = 1
  for hostname in statistics.DNSCache.keys():
    print n,'\t',hostname, '\t',statistics.DNSCache[hostname]
    n+=1
def dealwithResult(res,url):
  '''Deal with the result of downPage'''
  statistics.total_url+=1
  if res==statistics.RESULTFETCHED :
    statistics.fetched_url+=1
    print statistics.total_url , '\t fetched :', url
  if res==statistics.RESULTCANNOTFIND :
    statistics.failed_url+=1
    print "Error 404 at : ", url
  if res==statistics.RESULTOTHER :
    statistics.other_url +=1
    print "Error Undefined at : ", url
  if res==statistics.RESULTTIMEOUT :
    statistics.timeout_url +=1
    print "Timeout ",url
  if res==statistics.RESULTTRYTOOMANY:
    statistics.trytoomany_url+=1
    print e ,"Try too many times at", url
if __name__=='__main__':
  print 'Get Page using GET method'

'''
Created on 2012-3-16
@author: xiaojay
'''
import fetchPage
import threadpool
import datetime
import statistics
import urllib2
'''one thread'''
def usingOneThread(limit):
  urlset = open("input.txt","r")
  start = datetime.datetime.now()
  for u in urlset:
    if limit <= 0 : break
    limit-=1
    hostname , filename = parse(u)
    res= fetchPage.downPage(hostname,filename,0)
    fetchPage.dealwithResult(res)
  end = datetime.datetime.now()
  print "Start at :\t" , start
  print "End at :\t" , end
  print "Total Cost :\t" , end - start
  print &#39;Total fetched :&#39;, statistics.fetched_url
&#39;&#39;&#39;threadpoll and GET method&#39;&#39;&#39;
def callbackfunc(request,result):
  fetchPage.dealwithResult(result[0],result[1])
def usingThreadpool(limit,num_thread):
  urlset = open("input.txt","r")
  start = datetime.datetime.now()
  main = threadpool.ThreadPool(num_thread)
  for url in urlset :
    try :
      hostname , filename = fetchPage.parse(url)
      req = threadpool.WorkRequest(fetchPage.downPage,args=[hostname,filename],kwds={},callback=callbackfunc)
      main.putRequest(req)
    except Exception:
      print Exception.message
  while True:
    try:
      main.poll()
      if statistics.total_url >= limit : break
    except threadpool.NoResultsPending:
      print "no pending results"
      break
    except Exception ,e:
      print e
  end = datetime.datetime.now()
  print "Start at :\t" , start
  print "End at :\t" , end
  print "Total Cost :\t" , end - start
  print &#39;Total url :&#39;,statistics.total_url
  print &#39;Total fetched :&#39;, statistics.fetched_url
  print &#39;Lost url :&#39;, statistics.total_url - statistics.fetched_url
  print &#39;Error 404 :&#39; ,statistics.failed_url
  print &#39;Error timeout :&#39;,statistics.timeout_url
  print &#39;Error Try too many times &#39; ,statistics.trytoomany_url
  print &#39;Error Other faults &#39;,statistics.other_url
  main.stop()
&#39;&#39;&#39;threadpool and urllib2 &#39;&#39;&#39;
def downPageUsingUrlib2(url):
  try:
    req = urllib2.Request(url)
    fd = urllib2.urlopen(req)
    f = open("pages3/"+str(abs(hash(url))),&#39;w&#39;)
    f.write(fd.read())
    f.flush()
    f.close()
    return url ,&#39;success&#39;
  except Exception:
    return url , None
def writeFile(request,result):
  statistics.total_url += 1
  if result[1]!=None :
    statistics.fetched_url += 1
    print statistics.total_url,&#39;\tfetched :&#39;, result[0],
  else:
    statistics.failed_url += 1
    print statistics.total_url,&#39;\tLost :&#39;,result[0],
def usingThreadpoolUrllib2(limit,num_thread):
  urlset = open("input.txt","r")
  start = datetime.datetime.now()
  main = threadpool.ThreadPool(num_thread)
  for url in urlset :
    try :
      req = threadpool.WorkRequest(downPageUsingUrlib2,args=[url],kwds={},callback=writeFile)
      main.putRequest(req)
    except Exception ,e:
      print e
  while True:
    try:
      main.poll()
      if statistics.total_url >= limit : break
    except threadpool.NoResultsPending:
      print "no pending results"
      break
    except Exception ,e:
      print e
  end = datetime.datetime.now()
  print "Start at :\t" , start
  print "End at :\t" , end
  print "Total Cost :\t" , end - start
  print &#39;Total url :&#39;,statistics.total_url
  print &#39;Total fetched :&#39;, statistics.fetched_url
  print &#39;Lost url :&#39;, statistics.total_url - statistics.fetched_url
  main.stop()
if __name__ ==&#39;__main__&#39;:
  &#39;&#39;&#39;too slow&#39;&#39;&#39;
  #usingOneThread(100)
  &#39;&#39;&#39;use Get method&#39;&#39;&#39;
  #usingThreadpool(3000,50)
  &#39;&#39;&#39;use urllib2&#39;&#39;&#39;
  usingThreadpoolUrllib2(3000,50)