from jnpr.junos import Device
from jnpr.junos.utils.config import Config

dev = Device('juniper.device.example.com', user='netconf-user',
             password='some-pass', port=22, gather_facts=True)
dev.open()

cu = Config(dev)
try:
    cu.lock()
except:
    print 'Unable to lock'

try:
    load_args = {'path': './test.set'}
    cu.load(**load_args)
except Exception as e:
    print 'Exception'
    pass