How to use the pysftp.SSHException function in pysftp

params["password"] = self.sftp_password

            # not empty sftp_public_key means that we should verify sftp server with it
            cnopts = pysftp.CnOpts()
            if self.sftp_public_key:
                key = paramiko.RSAKey(data=base64.b64decode(self.sftp_public_key))
                cnopts.hostkeys.add(self.sftp_server, 'ssh-rsa', key)
            else:
                cnopts.hostkeys = None

            with pysftp.Connection(**params, cnopts=cnopts):
                raise exceptions.Warning(_("Connection Test Succeeded!"))

        except (pysftp.CredentialException,
                pysftp.ConnectionException,
                pysftp.SSHException):
            _logger.info("Connection Test Failed!", exc_info=True)
            raise exceptions.Warning(_("Connection Test Failed!"))

def upload(stop):
		while not stop.is_set():
			try:
				for fname in os.listdir(incomingpath):
					if fname.endswith('.pcap'):
						try:
							with pysftp.Connection(host=sshhost, username=sshuser, private_key='~/.ssh/id_rsa') as sftp:
								with sftp.cd(incomingpath):
									sftp.put(incomingpath +fname)
							logging.info("uploaded pcap") 
						except pysftp.SSHException:
							logging.info("Unable to establish SSH connection will retry in 5 min")
							time.sleep(300) #seconds
					os.remove(incomingpath +fname)
				else:
					logging.info("no pcap found, will try again in 5 min")
					time.sleep(300) #seconds
			except KeyboardInterrupt: pass
	stop = multiprocessing.Event()