from ydk.models.cisco_ios_xr import Cisco_IOS_XR_shellutil_cfg as xr_shellutil_cfg

new_hostname=xr_shellutil_cfg.HostNames()
new_hostname.host_name=-1

try:
    crud.update(provider,new_hostname)
except:
    print sys.exc_info()[0]

Executing CRUD update operation
=============Generating payload to send to device=============

<rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<edit-config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <target>
    <candidate/>
  </target>
  <error-option>rollback-on-error</error-option>
  <config><host-names xmlns="http://cisco.com/ns/yang/Cisco-IOS-XR-shellutil-cfg" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0" nc:operation="merge">
  <host-name>-1</host-name>
</host-names>
</config>
</edit-config>
</rpc>


=============Reply payload received from device=============

<?xml version="1.0"?>
<rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" message-id="25">
  <ok/>
</rpc-reply>



=============Executing commit=============

<rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <commit/>
</rpc>

=============Reply payload received from device=============

<?xml version="1.0"?>
<rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" message-id="26">
  <rpc-error>
    <error-type>application</error-type>
    <error-tag>operation-failed</error-tag>
    <error-severity>error</error-severity>
    <error-path xmlns:ns1="http://cisco.com/ns/yang/Cisco-IOS-XR-shellutil-cfg">ns1:host-names/ns1:host-name</error-path>
    <error-message xml:lang="en">The process 'syslogd' rejected the operation but returned no error</error-message>
  </rpc-error>
</rpc-reply>



RPC error occurred: <?xml version="1.0"?>
<rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" message-id="26">
  <rpc-error>
    <error-type>application</error-type>
    <error-tag>operation-failed</error-tag>
    <error-severity>error</error-severity>
    <error-path xmlns:ns1="http://cisco.com/ns/yang/Cisco-IOS-XR-shellutil-cfg">ns1:host-names/ns1:host-name</error-path>
    <error-message xml:lang="en">The process 'syslogd' rejected the operation but returned no error</error-message>
  </rpc-error>
</rpc-reply>