Unable to read configuration of the static routes

Trying to read configuration of the static routes (something that have been doing with ncclient). The code is simple: 

log = logging.getLogger('ydk')

log.setLevel(logging.DEBUG)

ch = logging.StreamHandler()

log.addHandler(ch) 

provider = NetconfServiceProvider(address=HOST, port=PORT, username=USER, password=PASS, protocol=PROTO) 

crud = CRUDService()

router_static = Cisco_IOS_XR_ip_static_cfg.RouterStatic()

crud.read(provider,router_static) 

print ("Printing static routes:\n")

for vrf_prefix in router_static.default_vrf.address_family.vrfipv4.vrf_unicast.vrf_prefixes.vrf_prefix:

   print(vrf_prefix.prefix + "/" + vrf_prefix.prefix_length)

print ("Done.\n") 

However, nothing happens although log shows that config has been read from the router:

<Log section is removed> 

Can the problem be the fact I'm not using lxml 3.4.4 but 3.7.2.

 Try

~/ > pip list|grep lxml

lxml (3.7.3)

Try the below script.

from ydk.models.cisco_ios_xr import Cisco_IOS_XR_ip_static_cfg 

import logging

log = logging.getLogger('ydk')

log.setLevel(logging.DEBUG)

ch = logging.StreamHandler()

log.addHandler(ch) 

from ydk.providers import NetconfServiceProvider

from ydk.services import CRUDService

crud = CRUDService()

ncc = NetconfServiceProvider(address='localhost' , username='vagrant', password='vagrant', port=830) 

router_static = crud.read(ncc,Cisco_IOS_XR_ip_static_cfg.RouterStatic())

for pref in router_static.default_vrf.address_family.vrfipv4.vrf_unicast.vrf_prefixes.vrf_prefix:

  print ( '{}/{}'.format(pref.prefix, pref.prefix_length))

dcloud is still running 0.5.3, can you run an instance, upgrade to 0.5.4 and try to reproduce.  You can upgrade using: 

$ sudo pip install ydk-models-cisco-ios-xr --upgrade

password is the same as username.