如何在PySNMP中标准化OID索引检索？

from pysnmp.hlapi import *

snmp_engine = SnmpEngine()

community = CommunityData('public', mpModel=0)
target = UdpTransportTarget(('localhost', 161))
context = ContextData()

oid_index = ObjectType(ObjectIdentity('IF-MIB', 'ifIndex'))

oid_value = ObjectType(ObjectIdentity('IF-MIB', 'ifDescr'))

error_indication, error_status, error_index, var_binds = next(
    getCmd(snmp_engine, community, target, context, oid_index, oid_value)
)

if error_indication:
    print('SNMP请求错误：{}'.format(error_indication))
else:
    if error_status:
        print('SNMP错误状态：{} at {}'.format(
            error_status.prettyPrint(), error_index and var_binds[int(error_index)-1][0] or '?'
        ))
    else:
        for var_bind in var_binds:
            print('OID索引：{}，OID值：{}'.format(var_bind[0], var_bind[1]))