https://github.com/mpenning/ciscoconfparse/issues/13

broken.cfg

!
router ospf
 area 0 
 timers throttle spf 5000 10000 20000
 distance external 125
 distance inter 125
 distance intra 125
!
router isis
 net 10.10.10.10.10
 fast-flood 5
 is-type level-2
 lsp-gen-interval 5
 log adjacency
 address-family ipv4 unicast
  default-metric 10
  maximum-paths 8
  metric-style wide
  redistribute connected
  redistribute static
 exit-address-family
 
 address-family ipv6 unicast
  default-metric 10
  maximum-paths 8
  redistribute connected
  redistribute static
 exit-address-family
 
!
!
router vrrp-extended
!
!
!
!
!
interface loopback 1
 ip address 192.168.0.1/32
 ipv6 address fe80::30/128
 ipv6 enable
 ipv6 router isis
 port-name the ipv6 address will be missing
!
interface loopback 2
 port-name brocade config example
 ip address 192.168.1.1/32
 ipv6 address fe80::1aaa/128
 ipv6 enable
!
!
end

broken.py

from ciscoconfparse import CiscoConfParse

broken = CiscoConfParse('broken.cfg', ignore_blank_lines=True)
notbroken = CiscoConfParse('broken.cfg', ignore_blank_lines=False)

print "broken:"
for child in broken.find_objects('^interface loopback 1$')[0].children:
    print child
print "not broken:"
for child in notbroken.find_objects('^interface loopback 1$')[0].children:
    print child