#! /usr/bin/env python
"""
Learning Series: Network Programmability Basics
Module: Programming Fundamentals
Lesson: Python Part 3
Author: Hank Preston <hapresto@cisco.com>

api_snmp_example.py
Illustrate the following concepts:
- How to make an SNMP GET with PySNMP 
- Intended to be entered into an interactive
  interpreter
"""

from pysnmp.hlapi import *
from pprint import pprint

router = {"ip": "10.10.20.48",
          "port": 161,
          "user": "cisco",
          "pass": "cisco_1234!"}

iterator = getCmd(SnmpEngine(),
                  CommunityData('public'),
                  UdpTransportTarget((router["ip"], router["port"])),
                  ContextData(),
                  ObjectType(ObjectIdentity('SNMPv2-MIB', 'sysDescr', 0)))

errorIndication, errorStatus, errorIndex, varBinds = next(iterator)

if errorIndication:  # SNMP engine errors
    print(errorIndication)
else:
    if errorStatus:  # SNMP agent errors
        print('%s at %s' % (errorStatus.prettyPrint(),
                            varBinds[int(errorIndex)-1] if errorIndex else '?'))
    else:
        for varBind in varBinds:  # SNMP response contents
            print(' = '.join([x.prettyPrint() for x in varBind]))