PEP-8 long lines and dunders (#245)

This patch massively reformats the whole codebase mainly wrapping
long lines and eliminating dundered private attributes.

9 files changed, 429 insertions, 192 deletions

diff --git a/pysnmp/entity/config.py b/pysnmp/entity/config.py
index 0ae87c0b..57e8704f 100644
--- a/pysnmp/entity/config.py
+++ b/pysnmp/entity/config.py
@@ -77,9 +77,13 @@ PRIV_SERVICES = {
 def __cookV1SystemInfo(snmpEngine, communityIndex):
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
-    snmpEngineID, = mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')
-    snmpCommunityEntry, = mibBuilder.importSymbols('SNMP-COMMUNITY-MIB', 'snmpCommunityEntry')
+    snmpEngineID, = mibBuilder.importSymbols(
+        '__SNMP-FRAMEWORK-MIB', 'snmpEngineID')
+    snmpCommunityEntry, = mibBuilder.importSymbols(
+        'SNMP-COMMUNITY-MIB', 'snmpCommunityEntry')
+
     tblIdx = snmpCommunityEntry.getInstIdFromIndices(communityIndex)
+
     return snmpCommunityEntry, tblIdx, snmpEngineID
 
 
@@ -91,6 +95,7 @@ def addV1System(snmpEngine, communityIndex, communityName,
 
     if contextEngineId is None:
         contextEngineId = snmpEngineID.syntax
+
     else:
         contextEngineId = snmpEngineID.syntax.clone(contextEngineId)
 
@@ -101,10 +106,13 @@ def addV1System(snmpEngine, communityIndex, communityName,
         (snmpCommunityEntry.name + (8,) + tblIdx, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (snmpCommunityEntry.name + (1,) + tblIdx, communityIndex),
         (snmpCommunityEntry.name + (2,) + tblIdx, communityName),
-        (snmpCommunityEntry.name + (3,) + tblIdx, securityName is not None and securityName or communityIndex),
+        (snmpCommunityEntry.name + (3,) + tblIdx, (
+                securityName is not None and securityName or
+                communityIndex)),
         (snmpCommunityEntry.name + (4,) + tblIdx, contextEngineId),
         (snmpCommunityEntry.name + (5,) + tblIdx, contextName),
         (snmpCommunityEntry.name + (6,) + tblIdx, transportTag),
@@ -117,6 +125,7 @@ def addV1System(snmpEngine, communityIndex, communityName,
 def delV1System(snmpEngine, communityIndex):
     (snmpCommunityEntry, tblIdx,
      snmpEngineID) = __cookV1SystemInfo(snmpEngine, communityIndex)
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (snmpCommunityEntry.name + (8,) + tblIdx, 'destroy'),
         snmpEngine=snmpEngine
@@ -126,17 +135,23 @@ def delV1System(snmpEngine, communityIndex):
 def __cookV3UserInfo(snmpEngine, securityName, securityEngineId):
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
-    snmpEngineID, = mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')
+    snmpEngineID, = mibBuilder.importSymbols(
+        '__SNMP-FRAMEWORK-MIB', 'snmpEngineID')
 
     if securityEngineId is None:
         snmpEngineID = snmpEngineID.syntax
+
     else:
         snmpEngineID = snmpEngineID.syntax.clone(securityEngineId)
 
-    usmUserEntry, = mibBuilder.importSymbols('SNMP-USER-BASED-SM-MIB', 'usmUserEntry')
+    usmUserEntry, = mibBuilder.importSymbols(
+        'SNMP-USER-BASED-SM-MIB', 'usmUserEntry')
+
     tblIdx1 = usmUserEntry.getInstIdFromIndices(snmpEngineID, securityName)
 
-    pysnmpUsmSecretEntry, = mibBuilder.importSymbols('PYSNMP-USM-MIB', 'pysnmpUsmSecretEntry')
+    pysnmpUsmSecretEntry, = mibBuilder.importSymbols(
+        'PYSNMP-USM-MIB', 'pysnmpUsmSecretEntry')
+
     tblIdx2 = pysnmpUsmSecretEntry.getInstIdFromIndices(securityName)
 
     return snmpEngineID, usmUserEntry, tblIdx1, pysnmpUsmSecretEntry, tblIdx2
@@ -147,24 +162,29 @@ def addV3User(snmpEngine, userName,
               privProtocol=USM_PRIV_NONE, privKey=None,
               securityEngineId=None,
               securityName=None):
+
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
     if securityName is None:
         securityName = userName
 
     (snmpEngineID, usmUserEntry, tblIdx1,
-     pysnmpUsmSecretEntry, tblIdx2) = __cookV3UserInfo(snmpEngine, userName, securityEngineId)
+     pysnmpUsmSecretEntry, tblIdx2) = __cookV3UserInfo(
+        snmpEngine, userName, securityEngineId)
 
     # Load augmenting table before creating new row in base one
-    pysnmpUsmKeyEntry, = mibBuilder.importSymbols('PYSNMP-USM-MIB', 'pysnmpUsmKeyEntry')
+    pysnmpUsmKeyEntry, = mibBuilder.importSymbols(
+        'PYSNMP-USM-MIB', 'pysnmpUsmKeyEntry')
 
     # Load clone-from (may not be needed)
-    zeroDotZero, = mibBuilder.importSymbols('SNMPv2-SMI', 'zeroDotZero')
+    zeroDotZero, = mibBuilder.importSymbols(
+        'SNMPv2-SMI', 'zeroDotZero')
 
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (usmUserEntry.name + (13,) + tblIdx1, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (usmUserEntry.name + (2,) + tblIdx1, userName),
         (usmUserEntry.name + (3,) + tblIdx1, securityName),
@@ -180,9 +200,11 @@ def addV3User(snmpEngine, userName,
         hashedAuthPassphrase = AUTH_SERVICES[authProtocol].hashPassphrase(
             authKey and authKey or null
         )
+
         localAuthKey = AUTH_SERVICES[authProtocol].localizeKey(
             hashedAuthPassphrase, snmpEngineID
         )
+
     else:
         raise error.PySnmpError('Unknown auth protocol %s' % (authProtocol,))
 
@@ -190,9 +212,11 @@ def addV3User(snmpEngine, userName,
         hashedPrivPassphrase = PRIV_SERVICES[privProtocol].hashPassphrase(
             authProtocol, privKey and privKey or null
         )
+
         localPrivKey = PRIV_SERVICES[privProtocol].localizeKey(
             authProtocol, hashedPrivPassphrase, snmpEngineID
         )
+
     else:
         raise error.PySnmpError('Unknown priv protocol %s' % (privProtocol,))
 
@@ -211,6 +235,7 @@ def addV3User(snmpEngine, userName,
         (pysnmpUsmSecretEntry.name + (4,) + tblIdx2, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (pysnmpUsmSecretEntry.name + (1,) + tblIdx2, userName),
         (pysnmpUsmSecretEntry.name + (2,) + tblIdx2, authKey),
@@ -225,10 +250,12 @@ def delV3User(snmpEngine,
               securityEngineId=None):
     (snmpEngineID, usmUserEntry, tblIdx1, pysnmpUsmSecretEntry,
      tblIdx2) = __cookV3UserInfo(snmpEngine, userName, securityEngineId)
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (usmUserEntry.name + (13,) + tblIdx1, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (pysnmpUsmSecretEntry.name + (4,) + tblIdx2, 'destroy'),
         snmpEngine=snmpEngine
@@ -272,6 +299,7 @@ def __cookTargetParamsInfo(snmpEngine, name):
 
     snmpTargetParamsEntry, = mibBuilder.importSymbols('SNMP-TARGET-MIB', 'snmpTargetParamsEntry')
     tblIdx = snmpTargetParamsEntry.getInstIdFromIndices(name)
+
     return snmpTargetParamsEntry, tblIdx
 
 
@@ -279,10 +307,13 @@ def __cookTargetParamsInfo(snmpEngine, name):
 def addTargetParams(snmpEngine, name, securityName, securityLevel, mpModel=3):
     if mpModel == 0:
         securityModel = 1
+
     elif mpModel in (1, 2):
         securityModel = 2
+
     elif mpModel == 3:
         securityModel = 3
+
     else:
         raise error.PySnmpError('Unknown MP model %s' % mpModel)
 
@@ -292,6 +323,7 @@ def addTargetParams(snmpEngine, name, securityName, securityLevel, mpModel=3):
         (snmpTargetParamsEntry.name + (7,) + tblIdx, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (snmpTargetParamsEntry.name + (1,) + tblIdx, name),
         (snmpTargetParamsEntry.name + (2,) + tblIdx, mpModel),
@@ -323,28 +355,36 @@ def __cookTargetAddrInfo(snmpEngine, addrName):
 def addTargetAddr(snmpEngine, addrName, transportDomain, transportAddress,
                   params, timeout=None, retryCount=None, tagList=null,
                   sourceAddress=None):
+
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
-    (snmpTargetAddrEntry, snmpSourceAddrEntry,
+    (snmpTargetAddrEntry,
+     snmpSourceAddrEntry,
      tblIdx) = __cookTargetAddrInfo(snmpEngine, addrName)
 
     if transportDomain[:len(SNMP_UDP_DOMAIN)] == SNMP_UDP_DOMAIN:
         SnmpUDPAddress, = mibBuilder.importSymbols('SNMPv2-TM', 'SnmpUDPAddress')
         transportAddress = SnmpUDPAddress(transportAddress)
+
         if sourceAddress is None:
             sourceAddress = ('0.0.0.0', 0)
+
         sourceAddress = SnmpUDPAddress(sourceAddress)
+
     elif transportDomain[:len(SNMP_UDP6_DOMAIN)] == SNMP_UDP6_DOMAIN:
         TransportAddressIPv6, = mibBuilder.importSymbols('TRANSPORT-ADDRESS-MIB', 'TransportAddressIPv6')
         transportAddress = TransportAddressIPv6(transportAddress)
+
         if sourceAddress is None:
             sourceAddress = ('::', 0)
+
         sourceAddress = TransportAddressIPv6(sourceAddress)
 
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (snmpTargetAddrEntry.name + (9,) + tblIdx, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (snmpTargetAddrEntry.name + (1,) + tblIdx, addrName),
         (snmpTargetAddrEntry.name + (2,) + tblIdx, transportDomain),
@@ -362,6 +402,7 @@ def addTargetAddr(snmpEngine, addrName, transportDomain, transportAddress,
 def delTargetAddr(snmpEngine, addrName):
     (snmpTargetAddrEntry, snmpSourceAddrEntry,
      tblIdx) = __cookTargetAddrInfo(snmpEngine, addrName)
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (snmpTargetAddrEntry.name + (9,) + tblIdx, 'destroy'),
         snmpEngine=snmpEngine
@@ -372,18 +413,23 @@ def addTransport(snmpEngine, transportDomain, transport):
     if snmpEngine.transportDispatcher:
         if not transport.isCompatibleWithDispatcher(snmpEngine.transportDispatcher):
             raise error.PySnmpError(
-                'Transport %r is not compatible with dispatcher %r' % (transport, snmpEngine.transportDispatcher))
+                'Transport %r is not compatible with dispatcher %r' % (
+                    transport, snmpEngine.transportDispatcher))
+
     else:
         snmpEngine.registerTransportDispatcher(
             transport.PROTO_TRANSPORT_DISPATCHER()
         )
+
         # here we note that we have created transportDispatcher automatically
         snmpEngine.setUserContext(automaticTransportDispatcher=0)
 
     snmpEngine.transportDispatcher.registerTransport(transportDomain, transport)
+
     automaticTransportDispatcher = snmpEngine.getUserContext(
         'automaticTransportDispatcher'
     )
+
     if automaticTransportDispatcher is not None:
         snmpEngine.setUserContext(
             automaticTransportDispatcher=automaticTransportDispatcher + 1
@@ -393,8 +439,10 @@ def addTransport(snmpEngine, transportDomain, transport):
 def getTransport(snmpEngine, transportDomain):
     if not snmpEngine.transportDispatcher:
         return
+
     try:
         return snmpEngine.transportDispatcher.getTransport(transportDomain)
+
     except error.PySnmpError:
         return
 
@@ -402,21 +450,26 @@ def getTransport(snmpEngine, transportDomain):
 def delTransport(snmpEngine, transportDomain):
     if not snmpEngine.transportDispatcher:
         return
+
     transport = getTransport(snmpEngine, transportDomain)
+
     snmpEngine.transportDispatcher.unregisterTransport(transportDomain)
+
     # automatically shutdown automatically created transportDispatcher
     automaticTransportDispatcher = snmpEngine.getUserContext(
         'automaticTransportDispatcher'
     )
+
     if automaticTransportDispatcher is not None:
         automaticTransportDispatcher -= 1
         snmpEngine.setUserContext(
-            automaticTransportDispatcher=automaticTransportDispatcher
-        )
+            automaticTransportDispatcher=automaticTransportDispatcher)
+
         if not automaticTransportDispatcher:
             snmpEngine.transportDispatcher.closeDispatcher()
             snmpEngine.unregisterTransportDispatcher()
             snmpEngine.delUserContext(automaticTransportDispatcher)
+
     return transport
 
 
@@ -428,8 +481,12 @@ delSocketTransport = delTransport
 
 def __cookVacmContextInfo(snmpEngine, contextName):
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
-    vacmContextEntry, = mibBuilder.importSymbols('SNMP-VIEW-BASED-ACM-MIB', 'vacmContextEntry')
+
+    vacmContextEntry, = mibBuilder.importSymbols(
+        'SNMP-VIEW-BASED-ACM-MIB', 'vacmContextEntry')
+
     tblIdx = vacmContextEntry.getInstIdFromIndices(contextName)
+
     return vacmContextEntry, tblIdx
 
 
@@ -440,6 +497,7 @@ def addContext(snmpEngine, contextName):
         (vacmContextEntry.name + (2,) + tblIdx, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (vacmContextEntry.name + (1,) + tblIdx, contextName),
         (vacmContextEntry.name + (2,) + tblIdx, 'createAndGo'),
@@ -459,20 +517,24 @@ def delContext(snmpEngine, contextName):
 def __cookVacmGroupInfo(snmpEngine, securityModel, securityName):
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
-    vacmSecurityToGroupEntry, = mibBuilder.importSymbols('SNMP-VIEW-BASED-ACM-MIB',
-                                                         'vacmSecurityToGroupEntry')
-    tblIdx = vacmSecurityToGroupEntry.getInstIdFromIndices(securityModel,
-                                                           securityName)
+    vacmSecurityToGroupEntry, = mibBuilder.importSymbols(
+        'SNMP-VIEW-BASED-ACM-MIB', 'vacmSecurityToGroupEntry')
+
+    tblIdx = vacmSecurityToGroupEntry.getInstIdFromIndices(
+        securityModel, securityName)
+
     return vacmSecurityToGroupEntry, tblIdx
 
 
 def addVacmGroup(snmpEngine, groupName, securityModel, securityName):
     (vacmSecurityToGroupEntry,
      tblIdx) = __cookVacmGroupInfo(snmpEngine, securityModel, securityName)
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (vacmSecurityToGroupEntry.name + (5,) + tblIdx, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (vacmSecurityToGroupEntry.name + (1,) + tblIdx, securityModel),
         (vacmSecurityToGroupEntry.name + (2,) + tblIdx, securityName),
@@ -486,6 +548,7 @@ def delVacmGroup(snmpEngine, securityModel, securityName):
     vacmSecurityToGroupEntry, tblIdx = __cookVacmGroupInfo(
         snmpEngine, securityModel, securityName
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (vacmSecurityToGroupEntry.name + (5,) + tblIdx, 'destroy'),
         snmpEngine=snmpEngine
@@ -496,17 +559,19 @@ def __cookVacmAccessInfo(snmpEngine, groupName, contextName, securityModel,
                          securityLevel):
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
-    vacmAccessEntry, = mibBuilder.importSymbols('SNMP-VIEW-BASED-ACM-MIB', 'vacmAccessEntry')
-    tblIdx = vacmAccessEntry.getInstIdFromIndices(groupName, contextName,
-                                                  securityModel, securityLevel)
+    vacmAccessEntry, = mibBuilder.importSymbols(
+        'SNMP-VIEW-BASED-ACM-MIB', 'vacmAccessEntry')
+
+    tblIdx = vacmAccessEntry.getInstIdFromIndices(
+        groupName, contextName, securityModel, securityLevel)
+
     return vacmAccessEntry, tblIdx
 
 
 def addVacmAccess(snmpEngine, groupName, contextName, securityModel,
                   securityLevel, prefix, readView, writeView, notifyView):
-    vacmAccessEntry, tblIdx = __cookVacmAccessInfo(snmpEngine, groupName,
-                                                   contextName, securityModel,
-                                                   securityLevel)
+    vacmAccessEntry, tblIdx = __cookVacmAccessInfo(
+        snmpEngine, groupName, contextName, securityModel, securityLevel)
 
     addContext(snmpEngine, contextName)
 
@@ -514,6 +579,7 @@ def addVacmAccess(snmpEngine, groupName, contextName, securityModel,
         (vacmAccessEntry.name + (9,) + tblIdx, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (vacmAccessEntry.name + (1,) + tblIdx, contextName),
         (vacmAccessEntry.name + (2,) + tblIdx, securityModel),
@@ -529,9 +595,9 @@ def addVacmAccess(snmpEngine, groupName, contextName, securityModel,
 
 def delVacmAccess(snmpEngine, groupName, contextName, securityModel,
                   securityLevel):
-    vacmAccessEntry, tblIdx = __cookVacmAccessInfo(snmpEngine, groupName,
-                                                   contextName, securityModel,
-                                                   securityLevel)
+
+    vacmAccessEntry, tblIdx = __cookVacmAccessInfo(
+        snmpEngine, groupName, contextName, securityModel, securityLevel)
 
     delContext(snmpEngine, contextName)
 
@@ -545,19 +611,23 @@ def __cookVacmViewInfo(snmpEngine, viewName, subTree):
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
     vacmViewTreeFamilyEntry, = mibBuilder.importSymbols(
-        'SNMP-VIEW-BASED-ACM-MIB', 'vacmViewTreeFamilyEntry'
-    )
+        'SNMP-VIEW-BASED-ACM-MIB', 'vacmViewTreeFamilyEntry')
+
     tblIdx = vacmViewTreeFamilyEntry.getInstIdFromIndices(viewName, subTree)
+
     return vacmViewTreeFamilyEntry, tblIdx
 
 
 def addVacmView(snmpEngine, viewName, viewType, subTree, mask):
-    vacmViewTreeFamilyEntry, tblIdx = __cookVacmViewInfo(snmpEngine, viewName,
-                                                         subTree)
+
+    vacmViewTreeFamilyEntry, tblIdx = __cookVacmViewInfo(
+        snmpEngine, viewName, subTree)
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (vacmViewTreeFamilyEntry.name + (6,) + tblIdx, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (vacmViewTreeFamilyEntry.name + (1,) + tblIdx, viewName),
         (vacmViewTreeFamilyEntry.name + (2,) + tblIdx, subTree),
@@ -569,8 +639,9 @@ def addVacmView(snmpEngine, viewName, viewType, subTree, mask):
 
 
 def delVacmView(snmpEngine, viewName, subTree):
-    vacmViewTreeFamilyEntry, tblIdx = __cookVacmViewInfo(snmpEngine, viewName,
-                                                         subTree)
+    vacmViewTreeFamilyEntry, tblIdx = __cookVacmViewInfo(
+        snmpEngine, viewName, subTree)
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (vacmViewTreeFamilyEntry.name + (6,) + tblIdx, 'destroy'),
         snmpEngine=snmpEngine
@@ -583,8 +654,11 @@ def __cookVacmUserInfo(snmpEngine, securityModel, securityName, securityLevel):
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
     groupName = 'v-%s-%d' % (hash(securityName), securityModel)
+
     SnmpSecurityLevel, = mibBuilder.importSymbols('SNMP-FRAMEWORK-MIB', 'SnmpSecurityLevel')
+
     securityLevel = SnmpSecurityLevel(securityLevel)
+
     return (groupName, securityLevel,
             'r' + groupName, 'w' + groupName, 'n' + groupName)
 
@@ -592,16 +666,22 @@ def __cookVacmUserInfo(snmpEngine, securityModel, securityName, securityLevel):
 def addVacmUser(snmpEngine, securityModel, securityName, securityLevel,
                 readSubTree=(), writeSubTree=(), notifySubTree=(),
                 contextName=null):
+
     (groupName, securityLevel, readView, writeView,
-     notifyView) = __cookVacmUserInfo(snmpEngine, securityModel, securityName,
-                                      securityLevel)
+     notifyView) = __cookVacmUserInfo(
+        snmpEngine, securityModel, securityName, securityLevel)
+
     addVacmGroup(snmpEngine, groupName, securityModel, securityName)
+
     addVacmAccess(snmpEngine, groupName, contextName, securityModel,
                   securityLevel, 1, readView, writeView, notifyView)
+
     if readSubTree:
         addVacmView(snmpEngine, readView, "included", readSubTree, null)
+
     if writeSubTree:
         addVacmView(snmpEngine, writeView, "included", writeSubTree, null)
+
     if notifySubTree:
         addVacmView(snmpEngine, notifyView, "included", notifySubTree, null)
 
@@ -610,43 +690,48 @@ def delVacmUser(snmpEngine, securityModel, securityName, securityLevel,
                 readSubTree=(), writeSubTree=(), notifySubTree=(),
                 contextName=null):
     (groupName, securityLevel, readView, writeView,
-     notifyView) = __cookVacmUserInfo(snmpEngine, securityModel,
-                                      securityName, securityLevel)
+     notifyView) = __cookVacmUserInfo(
+        snmpEngine, securityModel, securityName, securityLevel)
+
     delVacmGroup(snmpEngine, securityModel, securityName)
+
     delVacmAccess(snmpEngine, groupName, contextName, securityModel, securityLevel)
+
     if readSubTree:
-        delVacmView(
-            snmpEngine, readView, readSubTree
-        )
+        delVacmView(snmpEngine, readView, readSubTree)
+
     if writeSubTree:
-        delVacmView(
-            snmpEngine, writeView, writeSubTree
-        )
+        delVacmView(snmpEngine, writeView, writeSubTree)
+
     if notifySubTree:
-        delVacmView(
-            snmpEngine, notifyView, notifySubTree
-        )
+        delVacmView(snmpEngine, notifyView, notifySubTree)
 
 # Notification target setup
 
 def __cookNotificationTargetInfo(snmpEngine, notificationName, paramsName,
                                  filterSubtree=None):
+
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
-    snmpNotifyEntry, = mibBuilder.importSymbols('SNMP-NOTIFICATION-MIB', 'snmpNotifyEntry')
+    snmpNotifyEntry, = mibBuilder.importSymbols(
+        'SNMP-NOTIFICATION-MIB', 'snmpNotifyEntry')
+
     tblIdx1 = snmpNotifyEntry.getInstIdFromIndices(notificationName)
 
-    snmpNotifyFilterProfileEntry, = mibBuilder.importSymbols('SNMP-NOTIFICATION-MIB',
-                                                             'snmpNotifyFilterProfileEntry')
+    snmpNotifyFilterProfileEntry, = mibBuilder.importSymbols(
+        'SNMP-NOTIFICATION-MIB', 'snmpNotifyFilterProfileEntry')
+
     tblIdx2 = snmpNotifyFilterProfileEntry.getInstIdFromIndices(paramsName)
 
     profileName = '%s-filter' % hash(notificationName)
 
     if filterSubtree:
-        snmpNotifyFilterEntry, = mibBuilder.importSymbols('SNMP-NOTIFICATION-MIB',
-                                                          'snmpNotifyFilterEntry')
-        tblIdx3 = snmpNotifyFilterEntry.getInstIdFromIndices(profileName,
-                                                             filterSubtree)
+        snmpNotifyFilterEntry, = mibBuilder.importSymbols(
+            'SNMP-NOTIFICATION-MIB', 'snmpNotifyFilterEntry')
+
+        tblIdx3 = snmpNotifyFilterEntry.getInstIdFromIndices(
+            profileName, filterSubtree)
+
     else:
         snmpNotifyFilterEntry = tblIdx3 = None
 
@@ -658,15 +743,17 @@ def __cookNotificationTargetInfo(snmpEngine, notificationName, paramsName,
 def addNotificationTarget(snmpEngine, notificationName, paramsName,
                           transportTag, notifyType=None, filterSubtree=None,
                           filterMask=None, filterType=None):
+
     (snmpNotifyEntry, tblIdx1, snmpNotifyFilterProfileEntry, tblIdx2,
      profileName, snmpNotifyFilterEntry,
-     tblIdx3) = __cookNotificationTargetInfo(snmpEngine, notificationName,
-                                             paramsName, filterSubtree)
+     tblIdx3) = __cookNotificationTargetInfo(
+        snmpEngine, notificationName, paramsName, filterSubtree)
 
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (snmpNotifyEntry.name + (5,) + tblIdx1, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (snmpNotifyEntry.name + (2,) + tblIdx1, transportTag),
         (snmpNotifyEntry.name + (3,) + tblIdx1, notifyType),
@@ -678,6 +765,7 @@ def addNotificationTarget(snmpEngine, notificationName, paramsName,
         (snmpNotifyFilterProfileEntry.name + (3,) + tblIdx2, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (snmpNotifyFilterProfileEntry.name + (1,) + tblIdx2, profileName),
         (snmpNotifyFilterProfileEntry.name + (3,) + tblIdx2, 'createAndGo'),
@@ -691,6 +779,7 @@ def addNotificationTarget(snmpEngine, notificationName, paramsName,
         (snmpNotifyFilterEntry.name + (5,) + tblIdx3, 'destroy'),
         snmpEngine=snmpEngine
     )
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (snmpNotifyFilterEntry.name + (1,) + tblIdx3, filterSubtree),
         (snmpNotifyFilterEntry.name + (2,) + tblIdx3, filterMask),
@@ -704,8 +793,8 @@ def delNotificationTarget(snmpEngine, notificationName, paramsName,
                           filterSubtree=None):
     (snmpNotifyEntry, tblIdx1, snmpNotifyFilterProfileEntry,
      tblIdx2, profileName, snmpNotifyFilterEntry,
-     tblIdx3) = __cookNotificationTargetInfo(snmpEngine, notificationName,
-                                             paramsName, filterSubtree)
+     tblIdx3) = __cookNotificationTargetInfo(
+        snmpEngine, notificationName, paramsName, filterSubtree)
 
     snmpEngine.msgAndPduDsp.mibInstrumController.writeMibObjects(
         (snmpNotifyEntry.name + (5,) + tblIdx1, 'destroy'),
diff --git a/pysnmp/entity/engine.py b/pysnmp/entity/engine.py
index 60b45b0c..d7f16ff8 100644
--- a/pysnmp/entity/engine.py
+++ b/pysnmp/entity/engine.py
@@ -65,8 +65,12 @@ class SnmpEngine(object):
 
         if msgAndPduDsp is None:
             self.msgAndPduDsp = MsgAndPduDispatcher()
+
         else:
             self.msgAndPduDsp = msgAndPduDsp
+
+        mibBuilder = self.msgAndPduDsp.mibInstrumController.mibBuilder
+
         self.messageProcessingSubsystems = {
             SnmpV1MessageProcessingModel.MESSAGE_PROCESSING_MODEL_ID:
                 SnmpV1MessageProcessingModel(),
@@ -75,11 +79,13 @@ class SnmpEngine(object):
             SnmpV3MessageProcessingModel.MESSAGE_PROCESSING_MODEL_ID:
                 SnmpV3MessageProcessingModel()
         }
+
         self.securityModels = {
             SnmpV1SecurityModel.SECURITY_MODEL_ID: SnmpV1SecurityModel(),
             SnmpV2cSecurityModel.SECURITY_MODEL_ID: SnmpV2cSecurityModel(),
             SnmpUSMSecurityModel.SECURITY_MODEL_ID: SnmpUSMSecurityModel()
         }
+
         self.accessControlModel = {
             void.Vacm.ACCESS_MODEL_ID: void.Vacm(),
             rfc3415.Vacm.ACCESS_MODEL_ID: rfc3415.Vacm()
@@ -88,48 +94,59 @@ class SnmpEngine(object):
         self.transportDispatcher = None
 
         if self.msgAndPduDsp.mibInstrumController is None:
-            raise error.PySnmpError(
-                'MIB instrumentation does not yet exist'
-            )
-        snmpEngineMaxMessageSize, = self.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
+            raise error.PySnmpError('MIB instrumentation does not yet exist')
+
+        snmpEngineMaxMessageSize, = mibBuilder.importSymbols(
             '__SNMP-FRAMEWORK-MIB', 'snmpEngineMaxMessageSize')
+
         snmpEngineMaxMessageSize.syntax = snmpEngineMaxMessageSize.syntax.clone(maxMessageSize)
-        snmpEngineBoots, = self.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB',
-                                                                                           'snmpEngineBoots')
+
+        snmpEngineBoots, = mibBuilder.importSymbols(
+            '__SNMP-FRAMEWORK-MIB', 'snmpEngineBoots')
+
         snmpEngineBoots.syntax += 1
-        origSnmpEngineID, = self.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB',
-                                                                                            'snmpEngineID')
+
+        origSnmpEngineID, = mibBuilder.importSymbols(
+            '__SNMP-FRAMEWORK-MIB', 'snmpEngineID')
 
         if snmpEngineID is None:
             self.snmpEngineID = origSnmpEngineID.syntax
+
         else:
             origSnmpEngineID.syntax = origSnmpEngineID.syntax.clone(snmpEngineID)
             self.snmpEngineID = origSnmpEngineID.syntax
 
             debug.logger & debug.FLAG_APP and debug.logger(
-                'SnmpEngine: using custom SNMP Engine ID: %s' % self.snmpEngineID.prettyPrint())
+                'SnmpEngine: using custom SNMP Engine '
+                'ID: %s' % self.snmpEngineID.prettyPrint())
 
             # Attempt to make some of snmp Engine settings persistent.
             # This should probably be generalized as a non-volatile MIB store.
 
-            persistentPath = os.path.join(tempfile.gettempdir(), '__pysnmp', self.snmpEngineID.prettyPrint())
+            persistentPath = os.path.join(tempfile.gettempdir(), '__pysnmp',
+                                          self.snmpEngineID.prettyPrint())
 
-            debug.logger & debug.FLAG_APP and debug.logger('SnmpEngine: using persistent directory: %s' % persistentPath)
+            debug.logger & debug.FLAG_APP and debug.logger(
+                'SnmpEngine: using persistent directory: %s' % persistentPath)
 
             if not os.path.exists(persistentPath):
                 try:
                     os.makedirs(persistentPath)
+
                 except OSError:
                     return
 
             f = os.path.join(persistentPath, 'boots')
+
             try:
                 snmpEngineBoots.syntax = snmpEngineBoots.syntax.clone(open(f).read())
+
             except Exception:
                 pass
 
             try:
                 snmpEngineBoots.syntax += 1
+
             except Exception:
                 snmpEngineBoots.syntax = snmpEngineBoots.syntax.clone(1)
 
@@ -138,12 +155,15 @@ class SnmpEngine(object):
                 os.write(fd, str2octs(snmpEngineBoots.syntax.prettyPrint()))
                 os.close(fd)
                 shutil.move(fn, f)
+
             except Exception as exc:
                 debug.logger & debug.FLAG_APP and debug.logger(
                     'SnmpEngine: could not stored SNMP Engine Boots: %s' % exc)
+
             else:
                 debug.logger & debug.FLAG_APP and debug.logger(
-                    'SnmpEngine: stored SNMP Engine Boots: %s' % snmpEngineBoots.syntax.prettyPrint())
+                    'SnmpEngine: stored SNMP Engine Boots: '
+                    '%s' % snmpEngineBoots.syntax.prettyPrint())
 
     def __repr__(self):
         return '%s(snmpEngineID=%r)' % (self.__class__.__name__, self.snmpEngineID)
@@ -158,31 +178,28 @@ class SnmpEngine(object):
 
     def __receiveTimerTickCbFun(self, timeNow):
         self.msgAndPduDsp.receiveTimerTick(self, timeNow)
+
         for mpHandler in self.messageProcessingSubsystems.values():
             mpHandler.receiveTimerTick(self, timeNow)
+
         for smHandler in self.securityModels.values():
             smHandler.receiveTimerTick(self, timeNow)
 
     def registerTransportDispatcher(self, transportDispatcher, recvId=None):
-        if self.transportDispatcher is not None and \
-                self.transportDispatcher is not transportDispatcher:
-            raise error.PySnmpError(
-                'Transport dispatcher already registered'
-            )
-        transportDispatcher.registerRecvCbFun(
-            self.__receiveMessageCbFun, recvId
-        )
-        if self.transportDispatcher is None:
-            transportDispatcher.registerTimerCbFun(
-                self.__receiveTimerTickCbFun
-            )
+        if (self.transportDispatcher and
+                self.transportDispatcher is not transportDispatcher):
+            raise error.PySnmpError('Transport dispatcher already registered')
+
+        transportDispatcher.registerRecvCbFun(self.__receiveMessageCbFun, recvId)
+
+        if not self.transportDispatcher:
+            transportDispatcher.registerTimerCbFun(self.__receiveTimerTickCbFun)
             self.transportDispatcher = transportDispatcher
 
     def unregisterTransportDispatcher(self, recvId=None):
         if self.transportDispatcher is None:
-            raise error.PySnmpError(
-                'Transport dispatcher not registered'
-            )
+            raise error.PySnmpError('Transport dispatcher not registered')
+
         self.transportDispatcher.unregisterRecvCbFun(recvId)
         self.transportDispatcher.unregisterTimerCbFun()
         self.transportDispatcher = None
@@ -192,9 +209,7 @@ class SnmpEngine(object):
 
     # User app may attach opaque objects to SNMP Engine
     def setUserContext(self, **kwargs):
-        self.cache.update(
-            dict([('__%s' % k, kwargs[k]) for k in kwargs])
-        )
+        self.cache.update(dict([('__%s' % k, kwargs[k]) for k in kwargs]))
 
     def getUserContext(self, arg):
         return self.cache.get('__%s' % arg)
@@ -202,5 +217,6 @@ class SnmpEngine(object):
     def delUserContext(self, arg):
         try:
             del self.cache['__%s' % arg]
+
         except KeyError:
             pass
diff --git a/pysnmp/entity/observer.py b/pysnmp/entity/observer.py
index 3f7bd845..ddc959c3 100644
--- a/pysnmp/entity/observer.py
+++ b/pysnmp/entity/observer.py
@@ -31,21 +31,26 @@ class MetaObserver(object):
     def registerObserver(self, cbFun, *execpoints, **kwargs):
         if cbFun in self.__contexts:
             raise error.PySnmpError('duplicate observer %s' % cbFun)
+
         else:
             self.__contexts[cbFun] = kwargs.get('cbCtx')
+
         for execpoint in execpoints:
             if execpoint not in self.__observers:
                 self.__observers[execpoint] = []
+
             self.__observers[execpoint].append(cbFun)
 
     def unregisterObserver(self, cbFun=None):
         if cbFun is None:
             self.__observers.clear()
             self.__contexts.clear()
+
         else:
             for execpoint in dict(self.__observers):
                 if cbFun in self.__observers[execpoint]:
                     self.__observers[execpoint].remove(cbFun)
+
                 if not self.__observers[execpoint]:
                     del self.__observers[execpoint]
 
@@ -59,6 +64,7 @@ class MetaObserver(object):
         if execpoints:
             for execpoint in execpoints:
                 del self.__execpoints[execpoint]
+
         else:
             self.__execpoints.clear()
 
diff --git a/pysnmp/entity/rfc3413/cmdgen.py b/pysnmp/entity/rfc3413/cmdgen.py
index 6f13c265..17db6f33 100644
--- a/pysnmp/entity/rfc3413/cmdgen.py
+++ b/pysnmp/entity/rfc3413/cmdgen.py
@@ -49,7 +49,8 @@ class CommandGenerator(object):
         # 3.1.3
         if statusInformation:
             debug.logger & debug.FLAG_APP and debug.logger(
-                'processResponsePdu: sendPduHandle %s, statusInformation %s' % (sendPduHandle, statusInformation))
+                'processResponsePdu: sendPduHandle %s, statusInformation '
+                '%s' % (sendPduHandle, statusInformation))
 
             errorIndication = statusInformation['errorIndication']
 
@@ -60,16 +61,22 @@ class CommandGenerator(object):
                 origDiscoveryRetries = 0
                 origRetries += 1
 
-            if origRetries > origRetryCount or origDiscoveryRetries > self.__options.get('discoveryRetries', 4):
+            if (origRetries > origRetryCount or
+                    origDiscoveryRetries > self.__options.get('discoveryRetries', 4)):
+
                 debug.logger & debug.FLAG_APP and debug.logger(
-                    'processResponsePdu: sendPduHandle %s, retry count %d exceeded' % (sendPduHandle, origRetries))
-                cbFun(snmpEngine, origSendRequestHandle, errorIndication, None, cbCtx)
+                    'processResponsePdu: sendPduHandle %s, retry count %d '
+                    'exceeded' % (sendPduHandle, origRetries))
+
+                cbFun(snmpEngine, origSendRequestHandle,
+                      errorIndication, None, cbCtx)
                 return
 
             # User-side API assumes SMIv2
             if origMessageProcessingModel == 0:
                 reqPDU = rfc2576.v2ToV1(origPdu)
                 pduVersion = 0
+
             else:
                 reqPDU = origPdu
                 pduVersion = 1
@@ -92,16 +99,20 @@ class CommandGenerator(object):
                     origContextName, origPduVersion, origPdu, origTimeout,
                     origRetryCount, origRetries, origDiscoveryRetries
                 )
+
                 return
 
             except StatusInformation as exc:
                 statusInformation = exc
+
                 debug.logger & debug.FLAG_APP and debug.logger(
-                    'processResponsePdu: origSendRequestHandle %s, _sendPdu() failed with %r' % (
-                    sendPduHandle, statusInformation))
+                    'processResponsePdu: origSendRequestHandle %s, _sendPdu() '
+                    'failed with %r' % (sendPduHandle, statusInformation))
+
                 cbFun(snmpEngine, origSendRequestHandle,
                       statusInformation['errorIndication'],
                       None, cbCtx)
+
                 return
 
         if (origMessageProcessingModel != messageProcessingModel or
@@ -110,11 +121,14 @@ class CommandGenerator(object):
                 origContextEngineId and origContextEngineId != contextEngineId or
                 origContextName and origContextName != contextName or
                 origPduVersion != pduVersion):
+
             debug.logger & debug.FLAG_APP and debug.logger(
-                'processResponsePdu: sendPduHandle %s, request/response data mismatch' % sendPduHandle)
+                'processResponsePdu: sendPduHandle %s, request/response '
+                'data mismatch' % sendPduHandle)
 
             cbFun(snmpEngine, origSendRequestHandle,
                   'badResponse', None, cbCtx)
+
             return
 
         # User-side API assumes SMIv2
@@ -124,9 +138,12 @@ class CommandGenerator(object):
         # 3.1.2
         if v2c.apiPDU.getRequestID(PDU) != v2c.apiPDU.getRequestID(origPdu):
             debug.logger & debug.FLAG_APP and debug.logger(
-                'processResponsePdu: sendPduHandle %s, request-id/response-id mismatch' % sendPduHandle)
+                'processResponsePdu: sendPduHandle %s, request-id/response-id '
+                'mismatch' % sendPduHandle)
+
             cbFun(snmpEngine, origSendRequestHandle,
                   'badResponse', None, cbCtx)
+
             return
 
         cbFun(snmpEngine, origSendRequestHandle, None, PDU, cbCtx)
@@ -139,14 +156,18 @@ class CommandGenerator(object):
          securityLevel) = config.getTargetInfo(snmpEngine, targetName)
 
         # Convert timeout in seconds into timeout in timer ticks
-        timeoutInTicks = float(timeout) / 100 / snmpEngine.transportDispatcher.getTimerResolution()
+        timeoutInTicks = (float(timeout) / 100 /
+                          snmpEngine.transportDispatcher.getTimerResolution())
+
+        mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
-        SnmpEngineID, SnmpAdminString = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
+        SnmpEngineID, SnmpAdminString = mibBuilder.importSymbols(
             'SNMP-FRAMEWORK-MIB', 'SnmpEngineID', 'SnmpAdminString')
 
         # Cast possible strings into bytes
         if contextEngineId:
             contextEngineId = SnmpEngineID(contextEngineId)
+
         contextName = SnmpAdminString(contextName)
 
         origPDU = PDU
@@ -155,6 +176,7 @@ class CommandGenerator(object):
         if messageProcessingModel == 0:
             PDU = rfc2576.v2ToV1(PDU)
             pduVersion = 0
+
         else:
             pduVersion = 1
 
@@ -179,13 +201,14 @@ class CommandGenerator(object):
         )
 
         debug.logger & debug.FLAG_APP and debug.logger(
-            'sendPdu: sendPduHandle %s, timeout %d*10 ms/%d ticks, retry 0 of %d' % (
-                sendPduHandle, timeout, timeoutInTicks, retryCount))
+            'sendPdu: sendPduHandle %s, timeout %d*10 ms/%d ticks, retry '
+            '0 of %d' % (sendPduHandle, timeout, timeoutInTicks, retryCount))
 
         return sendRequestHandle
 
 
 class GetCommandGenerator(CommandGenerator):
+
     def processResponseVarBinds(self, snmpEngine, sendRequestHandle,
                                 errorIndication, PDU, cbCtx):
         cbFun, cbCtx = cbCtx
@@ -208,6 +231,7 @@ class GetCommandGenerator(CommandGenerator):
 
 
 class SetCommandGenerator(CommandGenerator):
+
     def processResponseVarBinds(self, snmpEngine, sendRequestHandle,
                                 errorIndication, PDU, cbCtx):
         cbFun, cbCtx = cbCtx
@@ -225,11 +249,12 @@ class SetCommandGenerator(CommandGenerator):
         v2c.apiPDU.setVarBinds(reqPDU, varBinds)
 
         return self.sendPdu(snmpEngine, targetName, contextEngineId,
-                            contextName, reqPDU,
-                            self.processResponseVarBinds, (cbFun, cbCtx))
+                            contextName, reqPDU, self.processResponseVarBinds,
+                            (cbFun, cbCtx))
 
 
 class NextCommandGeneratorSingleRun(CommandGenerator):
+
     def processResponseVarBinds(self, snmpEngine, sendRequestHandle,
                                 errorIndication, PDU, cbCtx):
         targetName, contextEngineId, contextName, reqPDU, cbFun, cbCtx = cbCtx
@@ -253,6 +278,7 @@ class NextCommandGeneratorSingleRun(CommandGenerator):
 
 
 class NextCommandGenerator(NextCommandGeneratorSingleRun):
+
     def processResponseVarBinds(self, snmpEngine, sendRequestHandle,
                                 errorIndication, PDU, cbCtx):
         targetName, contextEngineId, contextName, reqPDU, cbFun, cbCtx = cbCtx
@@ -266,8 +292,10 @@ class NextCommandGenerator(NextCommandGeneratorSingleRun):
 
         if v2c.apiPDU.getErrorStatus(PDU):
             errorIndication, varBinds = None, ()
+
         elif not varBindTable:
             errorIndication, varBinds = errind.emptyResponse, ()
+
         else:
             errorIndication, varBinds = v2c.apiPDU.getNextVarBinds(varBindTable[-1])
 
@@ -275,9 +303,11 @@ class NextCommandGenerator(NextCommandGeneratorSingleRun):
                      v2c.apiPDU.getErrorStatus(PDU),
                      v2c.apiPDU.getErrorIndex(PDU, muteErrors=True),
                      varBindTable, cbCtx):
+
             debug.logger & debug.FLAG_APP and debug.logger(
                 'processResponseVarBinds: sendRequestHandle %s, app says to stop walking' % sendRequestHandle)
-            return  # app says enough
+
+            return  # app says it's enough
 
         if not varBinds:
             return  # no more objects available
@@ -294,14 +324,18 @@ class NextCommandGenerator(NextCommandGeneratorSingleRun):
 
         except StatusInformation as exc:
             statusInformation = exc
+
             debug.logger & debug.FLAG_APP and debug.logger(
-                'sendVarBinds: sendPduHandle %s: sendPdu() failed with %r' % (sendRequestHandle, statusInformation))
+                'sendVarBinds: sendPduHandle %s: sendPdu() failed with '
+                '%r' % (sendRequestHandle, statusInformation))
+
             cbFun(snmpEngine, sendRequestHandle,
                   statusInformation['errorIndication'],
                   0, 0, (), cbCtx)
 
 
 class BulkCommandGeneratorSingleRun(CommandGenerator):
+
     def processResponseVarBinds(self, snmpEngine, sendRequestHandle,
                                 errorIndication, PDU, cbCtx):
         (targetName, nonRepeaters, maxRepetitions,
@@ -332,6 +366,7 @@ class BulkCommandGeneratorSingleRun(CommandGenerator):
 
 
 class BulkCommandGenerator(BulkCommandGeneratorSingleRun):
+
     def processResponseVarBinds(self, snmpEngine, sendRequestHandle,
                                 errorIndication, PDU, cbCtx):
         (targetName, nonRepeaters, maxRepetitions,
@@ -346,21 +381,27 @@ class BulkCommandGenerator(BulkCommandGeneratorSingleRun):
 
         if v2c.apiBulkPDU.getErrorStatus(PDU):
             errorIndication, varBinds = None, ()
+
         elif not varBindTable:
             errorIndication, varBinds = errind.emptyResponse, ()
+
         else:
             errorIndication, varBinds = v2c.apiBulkPDU.getNextVarBinds(varBindTable[-1])
             nonRepeaters = v2c.apiBulkPDU.getNonRepeaters(reqPDU)
+
             if nonRepeaters:
                 varBinds = v2c.apiBulkPDU.getVarBinds(reqPDU)[:int(nonRepeaters)] + varBinds[int(nonRepeaters):]
 
-        if not cbFun(snmpEngine, sendRequestHandle, errorIndication,
-                     v2c.apiBulkPDU.getErrorStatus(PDU),
-                     v2c.apiBulkPDU.getErrorIndex(PDU, muteErrors=True),
-                     varBindTable, cbCtx):
+        if not cbFun(
+                snmpEngine, sendRequestHandle, errorIndication,
+                v2c.apiBulkPDU.getErrorStatus(PDU),
+                v2c.apiBulkPDU.getErrorIndex(PDU, muteErrors=True),
+                varBindTable, cbCtx):
+
             debug.logger & debug.FLAG_APP and debug.logger(
                 'processResponseVarBinds: sendRequestHandle %s, app says to stop walking' % sendRequestHandle)
-            return  # app says enough
+
+            return  # app says it's enough
 
         if not varBinds:
             return  # no more objects available
@@ -369,16 +410,18 @@ class BulkCommandGenerator(BulkCommandGeneratorSingleRun):
         v2c.apiBulkPDU.setVarBinds(reqPDU, varBinds)
 
         try:
-            self.sendPdu(snmpEngine, targetName, contextEngineId,
-                         contextName, reqPDU,
-                         self.processResponseVarBinds,
-                         (targetName, nonRepeaters, maxRepetitions,
-                          contextEngineId, contextName, reqPDU, cbFun, cbCtx))
+            self.sendPdu(
+                snmpEngine, targetName, contextEngineId, contextName, reqPDU,
+                self.processResponseVarBinds,
+                (targetName, nonRepeaters, maxRepetitions,
+                    contextEngineId, contextName, reqPDU, cbFun, cbCtx))
 
         except StatusInformation as exc:
             statusInformation = exc
+
             debug.logger & debug.FLAG_APP and debug.logger(
-                'processResponseVarBinds: sendPduHandle %s: _sendPdu() failed with %r' % (
-                    sendRequestHandle, statusInformation))
+                'processResponseVarBinds: sendPduHandle %s: _sendPdu() failed '
+                'with %r' % (sendRequestHandle, statusInformation))
+
             cbFun(snmpEngine, sendRequestHandle,
                   statusInformation['errorIndication'], 0, 0, (), cbCtx)
diff --git a/pysnmp/entity/rfc3413/cmdrsp.py b/pysnmp/entity/rfc3413/cmdrsp.py
index 7910b86b..56eaaaf3 100644
--- a/pysnmp/entity/rfc3413/cmdrsp.py
+++ b/pysnmp/entity/rfc3413/cmdrsp.py
@@ -79,9 +79,8 @@ class CommandResponderBase(object):
         v2c.apiPDU.setVarBinds(PDU, varBinds)
 
         debug.logger & debug.FLAG_APP and debug.logger(
-            'sendVarBinds: stateReference %s, errorStatus %s, errorIndex %s, varBinds %s' % (
-            stateReference, errorStatus, errorIndex, varBinds)
-        )
+            'sendVarBinds: stateReference %s, errorStatus %s, errorIndex %s, '
+            'varBinds %s' % (stateReference, errorStatus, errorIndex, varBinds))
 
         self.sendPdu(snmpEngine, stateReference, PDU)
 
@@ -121,9 +120,12 @@ class CommandResponderBase(object):
 
         except error.StatusInformation as exc:
             debug.logger & debug.FLAG_APP and debug.logger(
-                'sendPdu: stateReference %s, statusInformation %s' % (stateReference, exc))
-            snmpSilentDrops, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMPv2-MIB',
-                                                                                                     'snmpSilentDrops')
+                'sendPdu: stateReference %s, statusInformation '
+                '%s' % (stateReference, exc))
+
+            snmpSilentDrops, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
+                '__SNMPv2-MIB', 'snmpSilentDrops')
+
             snmpSilentDrops.syntax += 1
 
     _getRequestType = rfc1905.GetRequestPDU.tagSet
@@ -172,6 +174,7 @@ class CommandResponderBase(object):
     def _storeAccessContext(snmpEngine):
         """Copy received message metadata while it lasts"""
         execCtx = snmpEngine.observer.getExecutionContext('rfc3412.receiveMessage:request')
+
         return {
             'securityModel': execCtx['securityModel'],
             'securityName': execCtx['securityName'],
@@ -205,14 +208,19 @@ class CommandResponderBase(object):
         # Map ACM errors onto SMI ones
         except error.StatusInformation as exc:
             statusInformation = exc
+
             debug.logger & debug.FLAG_APP and debug.logger(
-                '__verifyAccess: name %s, statusInformation %s' % (name, statusInformation))
+                '__verifyAccess: name %s, statusInformation '
+                '%s' % (name, statusInformation))
+
             errorIndication = statusInformation['errorIndication']
+
             # 3.2.5...
             if (errorIndication == errind.noSuchView or
                     errorIndication == errind.noAccessEntry or
                     errorIndication == errind.noGroupName):
-                raise pysnmp.smi.error.AuthorizationError(name=name, idx=context.get('idx'))
+                raise pysnmp.smi.error.AuthorizationError(
+                    name=name, idx=context.get('idx'))
 
             elif errorIndication == errind.otherError:
                 raise pysnmp.smi.error.GenError(name=name, idx=context.get('idx'))
@@ -221,16 +229,18 @@ class CommandResponderBase(object):
                 snmpUnknownContexts, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
                     '__SNMP-TARGET-MIB', 'snmpUnknownContexts')
                 snmpUnknownContexts.syntax += 1
+
                 # Request REPORT generation
-                raise pysnmp.smi.error.GenError(name=name, idx=context.get('idx'),
-                                                oid=snmpUnknownContexts.name,
-                                                val=snmpUnknownContexts.syntax)
+                raise pysnmp.smi.error.GenError(
+                    name=name, idx=context.get('idx'), oid=snmpUnknownContexts.name,
+                    val=snmpUnknownContexts.syntax)
 
             elif errorIndication == errind.notInView:
                 return True
 
             else:
                 raise error.ProtocolError('Unknown ACM error %s' % errorIndication)
+
         else:
             # rfc2576: 4.1.2.1
             if (securityModel == 1 and val is not None and
@@ -273,7 +283,6 @@ class CommandResponderBase(object):
         return errorIndication, errorStatus, errorIndex, varBinds
 
     def completeMgmtOperation(self, varBinds, **context):
-
         (errorIndication,
          errorStatus, errorIndex,
          varBinds) = self._mapSmiErrors(varBinds, **context)
@@ -330,11 +339,6 @@ class NextCommandResponder(CommandResponderBase):
     def _getManagedObjectsInstances(self, varBinds, **context):
         """Iterate over Managed Objects fulfilling SNMP query.
 
-        Parameters
-        ----------
-        varBinds
-        context
-
         Returns
         -------
         :py:class:`list` - List of Managed Objects Instances to respond with or
@@ -396,7 +400,7 @@ class NextCommandResponder(CommandResponderBase):
 
 class BulkCommandResponder(NextCommandResponder):
     SUPPORTED_PDU_TYPES = (rfc1905.GetBulkRequestPDU.tagSet,)
-    maxVarBinds = 64
+    MAX_VAR_BINDS = 64
 
     def _completeNonRepeaters(self, varBinds, **context):
         mgmtFun = context['mgmtFun']
@@ -470,7 +474,7 @@ class BulkCommandResponder(NextCommandResponder):
         R = max(len(varBinds) - N, 0)
 
         if R:
-            M = min(M, self.maxVarBinds // R)
+            M = min(M, self.MAX_VAR_BINDS // R)
 
         debug.logger & debug.FLAG_APP and debug.logger(
             'initiateMgmtOperation: N %d, M %d, R %d' % (N, M, R))
diff --git a/pysnmp/entity/rfc3413/config.py b/pysnmp/entity/rfc3413/config.py
index c58c74ba..162b70a0 100644
--- a/pysnmp/entity/rfc3413/config.py
+++ b/pysnmp/entity/rfc3413/config.py
@@ -36,7 +36,8 @@ def getTargetAddr(snmpEngine, snmpTargetAddrName):
             'snmpTargetAddrTAddress', 'snmpTargetAddrTimeout',
             'snmpTargetAddrRetryCount', 'snmpTargetAddrParams'
         )
-        snmpSourceAddrTAddress, = mibBuilder.importSymbols('PYSNMP-SOURCE-MIB', 'snmpSourceAddrTAddress')
+        snmpSourceAddrTAddress, = mibBuilder.importSymbols(
+            'PYSNMP-SOURCE-MIB', 'snmpSourceAddrTAddress')
 
         tblIdx = snmpTargetAddrEntry.getInstIdFromIndices(snmpTargetAddrName)
 
@@ -44,38 +45,46 @@ def getTargetAddr(snmpEngine, snmpTargetAddrName):
             snmpTargetAddrTDomain = snmpTargetAddrTDomain.getNode(
                 snmpTargetAddrTDomain.name + tblIdx
             ).syntax
+
             snmpTargetAddrTAddress = snmpTargetAddrTAddress.getNode(
                 snmpTargetAddrTAddress.name + tblIdx
             ).syntax
+
             snmpTargetAddrTimeout = snmpTargetAddrTimeout.getNode(
                 snmpTargetAddrTimeout.name + tblIdx
             ).syntax
+
             snmpTargetAddrRetryCount = snmpTargetAddrRetryCount.getNode(
                 snmpTargetAddrRetryCount.name + tblIdx
             ).syntax
+
             snmpTargetAddrParams = snmpTargetAddrParams.getNode(
                 snmpTargetAddrParams.name + tblIdx
             ).syntax
+
             snmpSourceAddrTAddress = snmpSourceAddrTAddress.getNode(
                 snmpSourceAddrTAddress.name + tblIdx
             ).syntax
+
         except NoSuchInstanceError:
             raise SmiError('Target %s not configured to LCD' % snmpTargetAddrName)
 
         transport = snmpEngine.transportDispatcher.getTransport(snmpTargetAddrTDomain)
 
         if snmpTargetAddrTDomain[:len(config.SNMP_UDP_DOMAIN)] == config.SNMP_UDP_DOMAIN:
-            SnmpUDPAddress, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMPv2-TM',
-                                                                                                    'SnmpUDPAddress')
+            SnmpUDPAddress, = mibBuilder.importSymbols('SNMPv2-TM', 'SnmpUDPAddress')
+
             snmpTargetAddrTAddress = transport.ADDRESS_TYPE(
                 SnmpUDPAddress(snmpTargetAddrTAddress)
             ).setLocalAddress(SnmpUDPAddress(snmpSourceAddrTAddress))
+
         elif snmpTargetAddrTDomain[:len(config.SNMP_UDP6_DOMAIN)] == config.SNMP_UDP6_DOMAIN:
-            TransportAddressIPv6, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
-                'TRANSPORT-ADDRESS-MIB', 'TransportAddressIPv6')
+            TransportAddressIPv6, = mibBuilder.importSymbols('TRANSPORT-ADDRESS-MIB', 'TransportAddressIPv6')
+
             snmpTargetAddrTAddress = transport.ADDRESS_TYPE(
                 TransportAddressIPv6(snmpTargetAddrTAddress)
             ).setLocalAddress(TransportAddressIPv6(snmpSourceAddrTAddress))
+
         elif snmpTargetAddrTDomain[:len(config.snmpLocalDomain)] == config.snmpLocalDomain:
             snmpTargetAddrTAddress = transport.ADDRESS_TYPE(
                 snmpTargetAddrTAddress
@@ -126,15 +135,19 @@ def getTargetParams(snmpEngine, paramsName):
             snmpTargetParamsMPModel = snmpTargetParamsMPModel.getNode(
                 snmpTargetParamsMPModel.name + tblIdx
             ).syntax
+
             snmpTargetParamsSecurityModel = snmpTargetParamsSecurityModel.getNode(
                 snmpTargetParamsSecurityModel.name + tblIdx
             ).syntax
+
             snmpTargetParamsSecurityName = snmpTargetParamsSecurityName.getNode(
                 snmpTargetParamsSecurityName.name + tblIdx
             ).syntax
+
             snmpTargetParamsSecurityLevel = snmpTargetParamsSecurityLevel.getNode(
                 snmpTargetParamsSecurityLevel.name + tblIdx
             ).syntax
+
         except NoSuchInstanceError:
             raise SmiError('Parameters %s not configured at LCD' % paramsName)
 
@@ -159,8 +172,8 @@ def getTargetInfo(snmpEngine, snmpTargetAddrName):
     (snmpTargetParamsMPModel,
      snmpTargetParamsSecurityModel,
      snmpTargetParamsSecurityName,
-     snmpTargetParamsSecurityLevel) = getTargetParams(snmpEngine,
-                                                      snmpTargetAddrParams)
+     snmpTargetParamsSecurityLevel) = getTargetParams(
+        snmpEngine, snmpTargetAddrParams)
 
     return (snmpTargetAddrTDomain, snmpTargetAddrTAddress,
             snmpTargetAddrTimeout, snmpTargetAddrRetryCount,
@@ -171,8 +184,8 @@ def getTargetInfo(snmpEngine, snmpTargetAddrName):
 def getNotificationInfo(snmpEngine, notificationTarget):
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
-    snmpNotifyEntry, = mibBuilder.importSymbols('SNMP-NOTIFICATION-MIB',
-                                                'snmpNotifyEntry')
+    snmpNotifyEntry, = mibBuilder.importSymbols(
+        'SNMP-NOTIFICATION-MIB', 'snmpNotifyEntry')
 
     cache = snmpEngine.getUserContext('getNotificationInfo')
     if cache is None:
@@ -185,10 +198,8 @@ def getNotificationInfo(snmpEngine, notificationTarget):
     targetToNotifyMap = cache['targetToNotifyMap']
 
     if notificationTarget not in targetToNotifyMap:
-        (snmpNotifyTag,
-         snmpNotifyType) = mibBuilder.importSymbols('SNMP-NOTIFICATION-MIB',
-                                                    'snmpNotifyTag',
-                                                    'snmpNotifyType')
+        snmpNotifyTag, snmpNotifyType = mibBuilder.importSymbols(
+            'SNMP-NOTIFICATION-MIB', 'snmpNotifyTag', 'snmpNotifyType')
 
         tblIdx = snmpNotifyEntry.getInstIdFromIndices(notificationTarget)
 
@@ -196,6 +207,7 @@ def getNotificationInfo(snmpEngine, notificationTarget):
             snmpNotifyTag = snmpNotifyTag.getNode(
                 snmpNotifyTag.name + tblIdx
             ).syntax
+
             snmpNotifyType = snmpNotifyType.getNode(
                 snmpNotifyType.name + tblIdx
             ).syntax
@@ -216,8 +228,8 @@ def getNotificationInfo(snmpEngine, notificationTarget):
 def getTargetNames(snmpEngine, tag):
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
-    snmpTargetAddrEntry, = mibBuilder.importSymbols('SNMP-TARGET-MIB',
-                                                    'snmpTargetAddrEntry')
+    snmpTargetAddrEntry, = mibBuilder.importSymbols(
+        'SNMP-TARGET-MIB', 'snmpTargetAddrEntry')
 
     cache = snmpEngine.getUserContext('getTargetNames')
     if cache is None:
@@ -226,6 +238,7 @@ def getTargetNames(snmpEngine, tag):
 
     if cache['id'] == snmpTargetAddrEntry.branchVersionId:
         tagToTargetsMap = cache['tagToTargetsMap']
+
     else:
         cache['tagToTargetsMap'] = {}
 
@@ -236,10 +249,13 @@ def getTargetNames(snmpEngine, tag):
             'SNMP-TARGET-MIB', 'SnmpTagValue', 'snmpTargetAddrName',
             'snmpTargetAddrTagList'
         )
+
         mibNode = snmpTargetAddrTagList
+
         while True:
             try:
                 mibNode = snmpTargetAddrTagList.getNextNode(mibNode.name)
+
             except NoSuchInstanceError:
                 break
 
@@ -249,8 +265,10 @@ def getTargetNames(snmpEngine, tag):
 
             for _tag in mibNode.syntax.asOctets().split():
                 _tag = SnmpTagValue(_tag)
+
                 if _tag not in tagToTargetsMap:
                     tagToTargetsMap[_tag] = []
+
                 tagToTargetsMap[_tag].append(_snmpTargetAddrName)
 
         cache['id'] = snmpTargetAddrEntry.branchVersionId
diff --git a/pysnmp/entity/rfc3413/context.py b/pysnmp/entity/rfc3413/context.py
index 9a99f284..8c759075 100644
--- a/pysnmp/entity/rfc3413/context.py
+++ b/pysnmp/entity/rfc3413/context.py
@@ -13,14 +13,20 @@ from pysnmp import error
 
 class SnmpContext(object):
     def __init__(self, snmpEngine, contextEngineId=None):
-        snmpEngineId, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB',
-                                                                                              'snmpEngineID')
+        mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
+
+        snmpEngineId, = mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')
+
         if contextEngineId is None:
             # Default to local snmpEngineId
             self.contextEngineId = snmpEngineId.syntax
+
         else:
             self.contextEngineId = snmpEngineId.syntax.clone(contextEngineId)
-        debug.logger & debug.FLAG_INS and debug.logger('SnmpContext: contextEngineId \"%r\"' % (self.contextEngineId,))
+
+        debug.logger & debug.FLAG_INS and debug.logger(
+            'SnmpContext: contextEngineId %r' % (self.contextEngineId,))
+
         self.contextNames = {
             null: snmpEngine.msgAndPduDsp.mibInstrumController  # Default name
         }
@@ -29,30 +35,35 @@ class SnmpContext(object):
         contextName = univ.OctetString(contextName).asOctets()
         if contextName in self.contextNames:
             raise error.PySnmpError(
-                'Duplicate contextName %s' % contextName
-            )
+                'Duplicate contextName %s' % contextName)
+
         debug.logger & debug.FLAG_INS and debug.logger(
             'registerContextName: registered contextName %r, mibInstrum %r' % (contextName, mibInstrum))
+
         if mibInstrum is None:
             self.contextNames[contextName] = self.contextNames[null]
+
         else:
             self.contextNames[contextName] = mibInstrum
 
     def unregisterContextName(self, contextName):
         contextName = univ.OctetString(contextName).asOctets()
+
         if contextName in self.contextNames:
             debug.logger & debug.FLAG_INS and debug.logger(
                 'unregisterContextName: unregistered contextName %r' % contextName)
+
             del self.contextNames[contextName]
 
     def getMibInstrum(self, contextName=null):
         contextName = univ.OctetString(contextName).asOctets()
         if contextName not in self.contextNames:
             debug.logger & debug.FLAG_INS and debug.logger('getMibInstrum: contextName %r not registered' % contextName)
-            raise error.PySnmpError(
-                'Missing contextName %s' % contextName
-            )
+
+            raise error.PySnmpError('Missing contextName %s' % contextName)
+
         else:
             debug.logger & debug.FLAG_INS and debug.logger(
                 'getMibInstrum: contextName %r, mibInstum %r' % (contextName, self.contextNames[contextName]))
+
             return self.contextNames[contextName]
diff --git a/pysnmp/entity/rfc3413/ntforg.py b/pysnmp/entity/rfc3413/ntforg.py
index e73dbf19..fc1e8c0a 100644
--- a/pysnmp/entity/rfc3413/ntforg.py
+++ b/pysnmp/entity/rfc3413/ntforg.py
@@ -29,6 +29,7 @@ class NotificationOriginator(object):
                            securityModel, securityName, securityLevel,
                            contextEngineId, contextName, pduVersion,
                            PDU, statusInformation, sendPduHandle, cbInfo):
+
         sendRequestHandle, cbFun, cbCtx = cbInfo
 
         # 3.3.6d
@@ -39,38 +40,48 @@ class NotificationOriginator(object):
          origMessageProcessingModel, origSecurityModel,
          origSecurityName, origSecurityLevel, origContextEngineId,
          origContextName, origPdu, origTimeout,
-         origRetryCount, origRetries, origDiscoveryRetries) = self.__pendingReqs.pop(sendPduHandle)
+         origRetryCount, origRetries,
+         origDiscoveryRetries) = self.__pendingReqs.pop(sendPduHandle)
 
         snmpEngine.transportDispatcher.jobFinished(id(self))
 
         if statusInformation:
             debug.logger & debug.FLAG_APP and debug.logger(
-                'processResponsePdu: sendRequestHandle %s, sendPduHandle %s statusInformation %s' % (
-                    sendRequestHandle, sendPduHandle, statusInformation))
+                'processResponsePdu: sendRequestHandle %s, sendPduHandle %s '
+                'statusInformation %s' % (sendRequestHandle, sendPduHandle,
+                                          statusInformation))
 
             errorIndication = statusInformation['errorIndication']
 
             if errorIndication in (errind.notInTimeWindow, errind.unknownEngineID):
                 origDiscoveryRetries += 1
                 origRetries = 0
+
             else:
                 origDiscoveryRetries = 0
                 origRetries += 1
 
-            if origRetries > origRetryCount or origDiscoveryRetries > self.__options.get('discoveryRetries', 4):
+            if (origRetries > origRetryCount or
+                    origDiscoveryRetries > self.__options.get('discoveryRetries', 4)):
+
                 debug.logger & debug.FLAG_APP and debug.logger(
-                    'processResponsePdu: sendRequestHandle %s, sendPduHandle %s retry count %d exceeded' % (
+                    'processResponsePdu: sendRequestHandle %s, sendPduHandle %s '
+                    'retry count %d exceeded' % (
                         sendRequestHandle, sendPduHandle, origRetries))
+
                 cbFun(snmpEngine, sendRequestHandle, errorIndication, None, cbCtx)
+
                 return
 
             # Convert timeout in seconds into timeout in timer ticks
-            timeoutInTicks = float(origTimeout) / 100 / snmpEngine.transportDispatcher.getTimerResolution()
+            timeoutInTicks = (float(origTimeout) / 100 /
+                              snmpEngine.transportDispatcher.getTimerResolution())
 
             # User-side API assumes SMIv2
             if messageProcessingModel == 0:
                 reqPDU = rfc2576.v2ToV1(origPdu)
                 pduVersion = 0
+
             else:
                 reqPDU = origPdu
                 pduVersion = 1
@@ -85,20 +96,26 @@ class NotificationOriginator(object):
                     reqPDU, True, timeoutInTicks, self.processResponsePdu,
                     (sendRequestHandle, cbFun, cbCtx)
                 )
+
             except error.StatusInformation as exc:
                 statusInformation = exc
+
                 debug.logger & debug.FLAG_APP and debug.logger(
-                    'processResponsePdu: sendRequestHandle %s: sendPdu() failed with %r ' % (
-                        sendRequestHandle, statusInformation))
+                    'processResponsePdu: sendRequestHandle %s: sendPdu() '
+                    'failed with %r ' % (sendRequestHandle, statusInformation))
+
                 cbFun(snmpEngine, sendRequestHandle,
                       statusInformation['errorIndication'], None, cbCtx)
+
                 return
 
             snmpEngine.transportDispatcher.jobStarted(id(self))
 
             debug.logger & debug.FLAG_APP and debug.logger(
-                'processResponsePdu: sendRequestHandle %s, sendPduHandle %s, timeout %d, retry %d of %d' % (
-                    sendRequestHandle, sendPduHandle, origTimeout, origRetries, origRetryCount))
+                'processResponsePdu: sendRequestHandle %s, sendPduHandle %s, '
+                'timeout %d, retry %d of %d' % (
+                    sendRequestHandle, sendPduHandle, origTimeout, origRetries,
+                    origRetryCount))
 
             # 3.3.6b
             self.__pendingReqs[sendPduHandle] = (
@@ -108,6 +125,7 @@ class NotificationOriginator(object):
                 origContextEngineId, origContextName, origPdu,
                 origTimeout, origRetryCount, origRetries, origDiscoveryRetries
             )
+
             return
 
         # 3.3.6c
@@ -129,6 +147,7 @@ class NotificationOriginator(object):
         if messageProcessingModel == 0:
             reqPDU = rfc2576.v2ToV1(pdu)
             pduVersion = 0
+
         else:
             reqPDU = pdu
             pduVersion = 1
@@ -136,7 +155,8 @@ class NotificationOriginator(object):
         # 3.3.5
         if reqPDU.tagSet in rfc3411.CONFIRMED_CLASS_PDUS:
             # Convert timeout in seconds into timeout in timer ticks
-            timeoutInTicks = float(timeout) / 100 / snmpEngine.transportDispatcher.getTimerResolution()
+            timeoutInTicks = (float(timeout) / 100 /
+                              snmpEngine.transportDispatcher.getTimerResolution())
 
             sendRequestHandle = getNextHandle()
 
@@ -158,7 +178,9 @@ class NotificationOriginator(object):
                 securityModel, securityName, securityLevel, contextEngineId,
                 contextName, pdu, timeout, retryCount, 0, 0
             )
+
             snmpEngine.transportDispatcher.jobStarted(id(self))
+
         else:
             snmpEngine.msgAndPduDsp.sendPdu(
                 snmpEngine, transportDomain, transportAddress,
@@ -180,14 +202,18 @@ class NotificationOriginator(object):
         self.__pendingNotifications[notificationHandle].remove(sendRequestHandle)
 
         debug.logger & debug.FLAG_APP and debug.logger(
-            'processResponseVarBinds: notificationHandle %s, sendRequestHandle %s, errorIndication %s, pending requests %s' % (
-                notificationHandle, sendRequestHandle, errorIndication, self.__pendingNotifications[notificationHandle]))
+            'processResponseVarBinds: notificationHandle %s, sendRequestHandle %s, '
+            'errorIndication %s, pending requests %s' % (
+                notificationHandle, sendRequestHandle, errorIndication,
+                self.__pendingNotifications[notificationHandle]))
 
         if not self.__pendingNotifications[notificationHandle]:
             debug.logger & debug.FLAG_APP and debug.logger(
-                'processResponseVarBinds: notificationHandle %s, sendRequestHandle %s -- completed' % (
-                    notificationHandle, sendRequestHandle))
+                'processResponseVarBinds: notificationHandle %s, sendRequestHandle %s '
+                '-- completed' % (notificationHandle, sendRequestHandle))
+
             del self.__pendingNotifications[notificationHandle]
+
             cbFun(snmpEngine, sendRequestHandle, errorIndication,
                   pdu and v2c.apiPDU.getErrorStatus(pdu) or 0,
                   pdu and v2c.apiPDU.getErrorIndex(pdu, muteErrors=True) or 0,
@@ -198,11 +224,14 @@ class NotificationOriginator(object):
     # Higher-level API to Notification Originator. Supports multiple
     # targets, automatic var-binding formation and is fully LCD-driven.
     #
+
     def sendVarBinds(self, snmpEngine, notificationTarget, contextEngineId,
                      contextName, varBinds=(), cbFun=None, cbCtx=None):
         debug.logger & debug.FLAG_APP and debug.logger(
-            'sendVarBinds: notificationTarget %s, contextEngineId %s, contextName "%s", varBinds %s' % (
-                notificationTarget, contextEngineId or '<default>', contextName, varBinds))
+            'sendVarBinds: notificationTarget %s, contextEngineId %s, '
+            'contextName "%s", varBinds %s' % (
+                notificationTarget, contextEngineId or '<default>',
+                contextName, varBinds))
 
         mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
 
@@ -251,6 +280,7 @@ class NotificationOriginator(object):
                 del varBinds[idx + 2]
                 if varBinds[1][0] == snmpTrapOID:
                     varBinds[1] = varBind
+
                 else:
                     varBinds.insert(1, varBind)
                 break
@@ -261,12 +291,14 @@ class NotificationOriginator(object):
 
         sendRequestHandle = -1
 
-        debug.logger & debug.FLAG_APP and debug.logger('sendVarBinds: final varBinds %s' % (varBinds,))
+        debug.logger & debug.FLAG_APP and debug.logger(
+            'sendVarBinds: final varBinds %s' % (varBinds,))
 
         for targetAddrName in config.getTargetNames(snmpEngine, notifyTag):
             (transportDomain, transportAddress, timeout,
              retryCount, params) = config.getTargetAddr(snmpEngine,
                                                         targetAddrName)
+
             (messageProcessingModel, securityModel, securityName,
              securityLevel) = config.getTargetParams(snmpEngine, params)
 
@@ -278,13 +310,16 @@ class NotificationOriginator(object):
             #              filterType) = config.getNotifyFilter(filterProfileName)
 
             debug.logger & debug.FLAG_APP and debug.logger(
-                'sendVarBinds: notificationHandle %s, notifyTag %s yields: transportDomain %s, transportAddress %r, securityModel %s, securityName %s, securityLevel %s' % (
-                    notificationHandle, notifyTag, transportDomain, transportAddress, securityModel,
-                    securityName, securityLevel))
+                'sendVarBinds: notificationHandle %s, notifyTag %s yields: '
+                'transportDomain %s, transportAddress %r, securityModel %s, '
+                'securityName %s, securityLevel %s' % (
+                    notificationHandle, notifyTag, transportDomain, transportAddress,
+                    securityModel, securityName, securityLevel))
 
             for varName, varVal in varBinds:
                 if varName in (sysUpTime, snmpTrapOID):
                     continue
+
                 try:
                     snmpEngine.accessControlModel[self.ACM_ID].isAccessAllowed(
                         snmpEngine, securityModel, securityName,
@@ -292,19 +327,22 @@ class NotificationOriginator(object):
                     )
 
                     debug.logger & debug.FLAG_APP and debug.logger(
-                        'sendVarBinds: ACL succeeded for OID %s securityName %s' % (varName, securityName))
+                        'sendVarBinds: ACL succeeded for OID %s securityName %s' % (
+                            varName, securityName))
 
                 except error.StatusInformation:
                     debug.logger & debug.FLAG_APP and debug.logger(
-                        'sendVarBinds: ACL denied access for OID %s securityName %s, droppping notification' % (
-                            varName, securityName))
+                        'sendVarBinds: ACL denied access for OID %s securityName %s,'
+                        'dropping notification' % (varName, securityName))
                     return
 
             # 3.3.4
             if notifyType == 1:
                 pdu = v2c.SNMPv2TrapPDU()
+
             elif notifyType == 2:
                 pdu = v2c.InformRequestPDU()
+
             else:
                 raise error.ProtocolError('Unknown notify-type %r', notifyType)
 
@@ -321,22 +359,27 @@ class NotificationOriginator(object):
 
             except error.StatusInformation as exc:
                 statusInformation = exc
+
                 debug.logger & debug.FLAG_APP and debug.logger(
-                    'sendVarBinds: sendRequestHandle %s: sendPdu() failed with %r' % (
-                        sendRequestHandle, statusInformation))
-                if notificationHandle not in self.__pendingNotifications or \
-                        not self.__pendingNotifications[notificationHandle]:
+                    'sendVarBinds: sendRequestHandle %s: sendPdu() failed '
+                    'with %r' % (sendRequestHandle, statusInformation))
+
+                if (notificationHandle not in self.__pendingNotifications or
+                        not self.__pendingNotifications[notificationHandle]):
+
                     if notificationHandle in self.__pendingNotifications:
                         del self.__pendingNotifications[notificationHandle]
+
                     if cbFun:
                         cbFun(snmpEngine, notificationHandle,
                               statusInformation['errorIndication'], 0, 0, (),
                               cbCtx)
+
                 return notificationHandle
 
             debug.logger & debug.FLAG_APP and debug.logger(
-                'sendVarBinds: notificationHandle %s, sendRequestHandle %s, timeout %d' % (
-                    notificationHandle, sendRequestHandle, timeout))
+                'sendVarBinds: notificationHandle %s, sendRequestHandle %s, '
+                'timeout %d' % (notificationHandle, sendRequestHandle, timeout))
 
             if notifyType == 2:
                 if notificationHandle not in self.__pendingNotifications:
@@ -344,8 +387,8 @@ class NotificationOriginator(object):
                 self.__pendingNotifications[notificationHandle].add(sendRequestHandle)
 
         debug.logger & debug.FLAG_APP and debug.logger(
-            'sendVarBinds: notificationHandle %s, sendRequestHandle %s, notification(s) sent' % (
-                notificationHandle, sendRequestHandle))
+            'sendVarBinds: notificationHandle %s, sendRequestHandle %s, '
+            'notification(s) sent' % (notificationHandle, sendRequestHandle))
 
         return notificationHandle
 
diff --git a/pysnmp/entity/rfc3413/ntfrcv.py b/pysnmp/entity/rfc3413/ntfrcv.py
index a4754be2..53cc7ac3 100644
--- a/pysnmp/entity/rfc3413/ntfrcv.py
+++ b/pysnmp/entity/rfc3413/ntfrcv.py
@@ -31,7 +31,8 @@ class NotificationReceiver(object):
         def storeSnmpTrapCommunity(snmpEngine, execpoint, variables, cbCtx):
             self.__snmpTrapCommunity = variables.get('communityName', '')
 
-        snmpEngine.observer.registerObserver(storeSnmpTrapCommunity, 'rfc2576.processIncomingMsg')
+        snmpEngine.observer.registerObserver(
+            storeSnmpTrapCommunity, 'rfc2576.processIncomingMsg')
 
     def close(self, snmpEngine):
         snmpEngine.msgAndPduDsp.unregisterContextEngineId(
@@ -48,6 +49,7 @@ class NotificationReceiver(object):
         if messageProcessingModel == 0:
             origPdu = PDU
             PDU = rfc2576.v1ToV2(PDU, snmpTrapCommunity=self.__snmpTrapCommunity)
+
         else:
             origPdu = None
 
@@ -89,12 +91,17 @@ class NotificationReceiver(object):
             except error.StatusInformation as exc:
                 debug.logger & debug.FLAG_APP and debug.logger(
                     'processPdu: stateReference %s, statusInformation %s' % (stateReference, exc))
-                snmpSilentDrops, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMPv2-MIB',
-                                                                                                         'snmpSilentDrops')
+
+                mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
+
+                snmpSilentDrops, = mibBuilder.importSymbols(
+                    '__SNMPv2-MIB', 'snmpSilentDrops')
+
                 snmpSilentDrops.syntax += 1
 
         elif PDU.tagSet in rfc3411.UNCONFIRMED_CLASS_PDUS:
             pass
+
         else:
             raise error.ProtocolError('Unexpected PDU class %s' % PDU.tagSet)