Add `hlapi.v1arch` API (#186)

* Add `hlapi.v1arch` API

Introduce new sub-package `pysnmp.hlapi.v1arch` which
wraps otherwise very detailed packet-level SNMP
messaging into a handful of convenience functions.

As a side effect, the `pysnmp.hlapi.*` sub-packages
moved under `pysnmp.hlapi.v3arch` though `pysnmp.hlapi`
still exposes `pysnmp.hlappi.v3arch.*` symbols to
retain some degree of backward compatibility.

The signature of the hlapi `.sendNotification()` call
has changed to accept `*varBinds` instead of a sequence
of `varBinds`. The rationale is to unify this method
call with similar methods of CommandGenerator.

* Add v1arch docs and reshuffle hlapi docs

1 files changed, 36 insertions, 0 deletions

diff --git a/examples/hlapi/v1arch/asyncore/sync/manager/cmdgen/fetch-variables-over-ipv6.py b/examples/hlapi/v1arch/asyncore/sync/manager/cmdgen/fetch-variables-over-ipv6.py
new file mode 100644
index 00000000..bd8d9ca2
--- /dev/null
+++ b/examples/hlapi/v1arch/asyncore/sync/manager/cmdgen/fetch-variables-over-ipv6.py
@@ -0,0 +1,36 @@
+"""
+GET over IPv6
++++++++++++++
+
+Send SNMP GET request using the following options:
+
+* with SNMPv2c, community 'public'
+* over IPv6/UDP
+* to an Agent at [::1]:161
+* for three OIDs in string form
+
+Functionally similar to:
+
+| $ snmpget -v2c -c public udp6:[::1]:161 1.3.6.1.2.1.1.1.0 1.3.6.1.2.1.1.2.0 1.3.6.1.2.1.1.3.0
+"""#
+from pysnmp.hlapi.v1arch import *
+
+errorIndication, errorStatus, errorIndex, varBinds = next(
+    getCmd(SnmpDispatcher(),
+           CommunityData('public'),
+           Udp6TransportTarget(('::1', 161)),
+           ('1.3.6.1.2.1.1.1.0', None),
+           ('1.3.6.1.2.1.1.2.0', None),
+           ('1.3.6.1.2.1.1.3.0', None))
+)
+
+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]))