python stmp debug 输出

需求如下：用python写个发送mail的程序 。开启debug 。现在想将这个debug写进一个文件中，代码如下 ：         stdout_  = sys.stdout         sys.stdout  = open("debug.txt","write")         try:                 s = smtplib.SMTP()                 s.set_debuglevel(1)                 s.connect(mail_host)                 s.login(mail_user,mail_pass)                 s.sendmail(me,mailto_list,msg.as_string())                 s.close()                 print "send_mail success"                 return True          except  Exception,e:                 print maildebug                 print "send_mail false"                 return False         sys.stdout   = stdout_ 

from sys import stderr if self.debuglevel > 0:                 print>>stderr, 'connect:', (host, port) 

              s = smtplib.SMTP()               s.set_debuglevel(1)               smtplib.stderr=open("debug.txt","write")               s.connect(mail_host)               s.login(mail_user,mail_pass)               s.sendmail(me,mailto_list,msg.as_string())               s.close()