python实现ftp上传下载及断点续传

#!/usr/bin/python  #encoding=utf-8    from ftplib import FTP      import sys      import os.path            class MyFTP(FTP):       '''     conncet to FTP Server     '''       def __init__(self):      print 'make a object'     def ConnectFTP(self,remoteip,remoteport,loginname,loginpassword):        ftp=MyFTP()        try:       ftp.connect(remoteip,remoteport,600)       print 'success'      except Exception, e:     print >> sys.stderr, "conncet failed1 - %s" % e     return (0,'conncet failed')        else:         try:          ftp.login(loginname,loginpassword)          print('login success')      except Exception, e:      print >>sys.stderr, 'login failed - %s' % e      return (0,'login failed')         else:      print 'return 1'      return (1,ftp)           def download(self,remoteHost,remotePort,loginname,loginpassword,remotePath,localPath):        #connect to the FTP Server and check the return        res = self.ConnectFTP(remoteHost,remotePort,loginname,loginpassword)        if(res[0]!=1):     print >>sys.stderr, res[1]     sys.exit()         #change the remote directory and get the remote file size        ftp=res[1]    ftp.set_pasv(0)    dires = self.splitpath(remotePath)    if dires[0]:     ftp.cwd(dires[0])   # change remote work dir     remotefile=dires[1]     # remote file name    print dires[0]+' '+ dires[1]        fsize=ftp.size(remotefile)        if fsize==0 : # localfime's site is 0     return         #check local file isn't exists and get the local file size        lsize=0L    if os.path.exists(localPath):         lsize=os.stat(localPath).st_size              if lsize >= fsize:         print 'local file is bigger or equal remote file'         return        blocksize=1024 * 1024    cmpsize=lsize    ftp.voidcmd('TYPE I')    conn = ftp.transfercmd('RETR '+remotefile,lsize)    lwrite=open(localPath,'ab')    while True:     data=conn.recv(blocksize)     if not data:      break      lwrite.write(data)     cmpsize+=len(data)     print '\b'*30,'download process:%.2f%%'%(float(cmpsize)/fsize*100),    lwrite.close()    ftp.voidcmd('NOOP')    ftp.voidresp()    conn.close()    ftp.quit()     def upload(self,remotehost,remoteport,loginname,loginpassword,remotepath,localpath,callback=None):    if not os.path.exists(localpath):     print "Local file doesn't exists"     return    self.set_debuglevel(2)    res=self.ConnectFTP(remotehost,remoteport,loginname,loginpassword)    if res[0]!=1:     print res[1]     sys.exit()    ftp=res[1]    remote=self.splitpath(remotepath)    ftp.cwd(remote[0])    rsize=0L    try:     rsize=ftp.size(remote[1])    except:     pass    if (rsize==None):     rsize=0L    lsize=os.stat(localpath).st_size    print('rsize : %d, lsize : %d' % (rsize, lsize))    if (rsize==lsize):     print 'remote filesize is equal with local'     return    if (rsize<lsize):     localf=open(localpath,'rb')     localf.seek(rsize)     ftp.voidcmd('TYPE I')     datasock=''     esize=''     try:      print(remote[1])      datasock,esize=ftp.ntransfercmd("STOR "+remote[1],rsize)     except Exception, e:      print >>sys.stderr, '----------ftp.ntransfercmd-------- : %s' % e      return     cmpsize=rsize     while True:      buf=localf.read(1024 * 1024)      if not len(buf):       print '\rno data break'       break      datasock.sendall(buf)      if callback:       callback(buf)      cmpsize+=len(buf)      print '\b'*30,'uploading %.2f%%'%(float(cmpsize)/lsize*100),      if cmpsize==lsize:       print '\rfile size equal break'       break     datasock.close()     print 'close data handle'     localf.close()     print 'close local file handle'     ftp.voidcmd('NOOP')     print 'keep alive cmd success'     ftp.voidresp()     print 'No loop cmd'     ftp.quit()     def splitpath(self,remotepath):    position=remotepath.rfind('/')    return (remotepath[:position+1],remotepath[position+1:])