"""
Walk MIB, limit number of response rows
+++++++++++++++++++++++++++++++++++++++

Send a series of SNMP GETBULK requests using the following options:

* with SNMPv2c, community 'public'
* over IPv4/UDP
* to an Agent at demo.snmplabs.com:161
* with values non-repeaters = 0, max-repetitions = 25
* for two OIDs in string form
* stop when response OIDs leave the scopes of initial OIDs OR
  number of response rows reach fixed value (20)

Functionally similar to:

| $ snmpbulkwalk -v2c -c public demo.snmplabs.com -Cn0 -Cr25 1.3.6.1.2.1.2.2 1.3.6.1.2.1.2.3

"""#
from pysnmp.hlapi import *

for (errorIndication,
     errorStatus,
     errorIndex,
     varBinds) in bulkCmd(SnmpEngine(),
                          CommunityData('public'),
                          UdpTransportTarget(('demo.snmplabs.com', 161)),
                          ContextData(),
                          0, 25,
                          ObjectType(ObjectIdentity('1.3.6.1.2.1.2.2')),
                          ObjectType(ObjectIdentity('1.3.6.1.2.1.2.3')),
                          lexicographicMode=False, maxRows=20):

    if errorIndication:
        print(errorIndication)
        break
    elif errorStatus:
        print('%s at %s' % (errorStatus.prettyPrint(),
                            errorIndex and varBinds[int(errorIndex)-1][0] or '?'))
        break
    else:
        for varBind in varBinds:
            print(' = '.join([ x.prettyPrint() for x in varBind ]))
