catching exceptions with python easysnmp

Question

I cannot seem to find documentation or examples of how to catch exceptions with Python's easySNMP library

https://easysnmp.readthedocs.io/en/latest/exceptions.html shows what exceptions are rasied but I get errors when trying to catch them

Simplified code:

from easysnmp import Session
try:
    session = Session(hostname=host,community=community, version=2)
except:
    print("ERROR - SNMP error:")
    sys.exit(3)    

def check_snmp(oid):
    try:
        ret = session.get(oid).value
    except easysnmp.EasySNMPNoSuchInstanceError:
        ## Return false if OID doesn't exists
        return 0
    except session.EasySNMPError as e:
        ## Print the error on general errors
        print("ERROR - SNMP error: {}".format(e))
    return 1

if check_snnp('ifalias.4'):
    print("SNMP returned true")

Output:

Traceback (most recent call last):
    File "./check_ip_route", line 72, in <module>
    if check_snmp(oid):
    File "./check_snmp", line 45, in check_snmp
        except easysnmp.EasySNMPNoSuchInstanceError:
    NameError: name 'easysnmp' is not defined

score 1 · Accepted Answer · answered Nov 26 '18 at 13:35

1

Your error says name 'easysnmp' is not defined.

That is because you haven't imported it.

Instead you imported from easysnmp import Session

you need to do import easysnmp

answered Nov 26 '18 at 13:35

Kishor Pawar

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2

And change `session = Session` to `session = easysnmp.Session` – T Burgis Nov 26 '18 at 13:36
1

he can have his existing import as it is, right, @TBurgis? – Kishor Pawar Nov 26 '18 at 13:37
1

He also uses `easysnmp.EasySNMPNoSuchInstanceError`. With two imports as per your answer there will be two namespaces with `Session`. I would either import the whole module or explicitly import the bits required, not a mixture of the two. – T Burgis Nov 26 '18 at 13:40
1

I see, two namespaces would be unnecessary. Got it. – Kishor Pawar Nov 26 '18 at 13:42
Thank you both, how I didn't see where I was going wrong I don't know! Blaming it on the Mondays – doghousedean Nov 26 '18 at 13:43

catching exceptions with python easysnmp

1 Answers1