def _compute_host(host, instance):
 if host:
  return host
 if (not instance):
  raise exception.NovaException(_('No compute host specified'))
 if (not instance.host):
  raise exception.NovaException((_('Unable to find host for Instance %s') % instance.uuid))
 return instance.host

def _compute_host ( host , instance ) : if host : return host if ( not instance ) : raise exception . NovaException ( _ ( 'No compute host specified' ) ) if ( not instance . host ) : raise exception . NovaException ( ( _ ( 'Unable to find host for Instance %s' ) % instance . uuid ) ) return instance . host
get the destination host for a message .