def test1():
 import os
 return1=os.system('ping 8.8.8.8')
 if return1:
  print 'ping fail'
  os.system('msdt.exe /id NetworkDiagnosticsNetworkAdapter')#调用系统网络诊断
 else:
  print 'ping'
def test2():
 import os
 import subprocess
 
 fnull = open(os.devnull, 'w')
 return1 = subprocess.call('ping 8.8.8.8', shell = True, stdout = fnull, stderr = fnull)
 if return1:
  return1 = subprocess.call('msdt.exe /id NetworkDiagnosticsNetworkAdapter', shell=True, stdout=fnull, stderr=fnull)
  print 'ping fail'
 else:
  print 'ping ok'
 fnull.close()
 
if __name__=='__main__':
 test2()