Accessing the gerrit SSH interface using Python (via ssh config entry)

gerrit-ssh.py

#!/usr/bin/env python
import paramiko
import sys
import os

client = paramiko.SSHClient()
client.load_system_host_keys()
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

config = paramiko.SSHConfig()
config.parse(open(os.path.expanduser('~/.ssh/config')))
host = config.lookup('gerrit') # name of ssh config entry

client.connect(host['hostname'], username=host['user'], port=int(host['port']), key_filename=host['identityfile'])
stdin, stdout, stderr = client.exec_command('gerrit ls-projects')

print(stdout.readlines())
client.close()

In version of gerrit 2.16 ,will stop in line 15, don't response. how can i do???

my environment：
python version:3.7.1
paramiko version: 2.4.2