"""
SNMPv3: no auth, no privacy
+++++++++++++++++++++++++++

Send SNMP GET request using the following options:

* with SNMPv3, user 'usr-none-none', no authentication, no encryption
* over IPv4/UDP
* to an Agent at demo.snmplabs.com:161
* for IF-MIB::ifInOctets.1 MIB object

Functionally similar to:

| $ snmpget -v3 -l noAuthNoPriv -u usr-none-none
|           demo.snmplabs.com \
|           IF-MIB::ifInOctets.1

"""#
from pysnmp.entity.rfc3413.oneliner.cmdgen import *

errorIndication, errorStatus, errorIndex, varBinds = next(
    getCmd(SnmpEngine(),
            UsmUserData('usr-none-none'),
            UdpTransportTarget(('demo.snmplabs.com', 161)),
            ContextData(),
            ObjectType(ObjectIdentity('IF-MIB', 'ifInOctets', 1)))
)

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