pep8 reformatted

22 files changed, 635 insertions, 281 deletions

diff --git a/pysnmp/proto/cache.py b/pysnmp/proto/cache.py
index eb3e3b69..a86b991c 100644
--- a/pysnmp/proto/cache.py
+++ b/pysnmp/proto/cache.py
@@ -6,6 +6,7 @@
 #
 from pysnmp.proto import error
 
+
 class Cache:
     def __init__(self):
         self.__cacheRepository = {}
@@ -26,7 +27,7 @@ class Cache:
         if index not in self.__cacheRepository:
             raise error.ProtocolError(
                 'Cache miss on update for %s' % kwargs
-                )
+            )
         self.__cacheRepository[index].update(kwargs)
 
     def expire(self, cbFun, cbCtx):
diff --git a/pysnmp/proto/errind.py b/pysnmp/proto/errind.py
index f11c1fa1..12402ea1 100644
--- a/pysnmp/proto/errind.py
+++ b/pysnmp/proto/errind.py
@@ -4,8 +4,11 @@
 # Copyright (c) 2005-2016, Ilya Etingof <ilya@glas.net>
 # License: http://pysnmp.sf.net/license.html
 #
+
+
 class ErrorIndication:
     """SNMPv3 error-indication values"""
+
     def __init__(self, descr=None):
         self.__value = self.__descr = self.__class__.__name__[0].lower() + self.__class__.__name__[1:]
         if descr:
@@ -32,190 +35,262 @@ class ErrorIndication:
     def __str__(self):
         return self.__descr
 
+
 # SNMP message processing errors
 
 class SerializationError(ErrorIndication):
     pass
 
+
 serializationError = SerializationError('SNMP message serialization error')
 
+
 class DeserializationError(ErrorIndication):
     pass
 
+
 deserializationError = DeserializationError('SNMP message deserialization error')
 
+
 class ParseError(DeserializationError):
     pass
 
+
 parseError = ParseError('SNMP message deserialization error')
 
+
 class UnsupportedMsgProcessingModel(ErrorIndication):
     pass
 
+
 unsupportedMsgProcessingModel = UnsupportedMsgProcessingModel('Unknown SNMP message processing model ID encountered')
 
+
 class UnknownPDUHandler(ErrorIndication):
     pass
 
+
 unknownPDUHandler = UnknownPDUHandler('Unhandled PDU type encountered')
 
+
 class UnsupportedPDUtype(ErrorIndication):
     pass
 
+
 unsupportedPDUtype = UnsupportedPDUtype('Unsupported SNMP PDU type encountered')
 
+
 class RequestTimedOut(ErrorIndication):
     pass
 
+
 requestTimedOut = RequestTimedOut('No SNMP response received before timeout')
 
+
 class EmptyResponse(ErrorIndication):
     pass
 
+
 emptyResponse = EmptyResponse('Empty SNMP response message')
 
+
 class NonReportable(ErrorIndication):
     pass
 
+
 nonReportable = NonReportable('Report PDU generation not attempted')
 
+
 class DataMismatch(ErrorIndication):
     pass
 
+
 dataMismatch = DataMismatch('SNMP request/response parameters mismatched')
 
+
 class EngineIDMismatch(ErrorIndication):
     pass
 
+
 engineIDMismatch = EngineIDMismatch('SNMP engine ID mismatch encountered')
 
+
 class UnknownEngineID(ErrorIndication):
     pass
 
+
 unknownEngineID = UnknownEngineID('Unknown SNMP engine ID encountered')
 
+
 class TooBig(ErrorIndication):
     pass
 
+
 tooBig = TooBig('SNMP message will be too big')
 
+
 class LoopTerminated(ErrorIndication):
     pass
 
+
 loopTerminated = LoopTerminated('Infinite SNMP entities talk terminated')
 
+
 class InvalidMsg(ErrorIndication):
     pass
 
+
 invalidMsg = InvalidMsg('Invalid SNMP message header parameters encountered')
 
+
 # SNMP security modules errors
 
 class UnknownCommunityName(ErrorIndication):
     pass
 
+
 unknownCommunityName = UnknownCommunityName('Unknown SNMP community name encountered')
 
+
 class NoEncryption(ErrorIndication):
     pass
 
+
 noEncryption = NoEncryption('No encryption services configured')
 
+
 class EncryptionError(ErrorIndication):
     pass
 
+
 encryptionError = EncryptionError('Ciphering services not available')
 
+
 class DecryptionError(ErrorIndication):
     pass
 
+
 decryptionError = DecryptionError('Ciphering services not available or ciphertext is broken')
 
+
 class NoAuthentication(ErrorIndication):
     pass
 
+
 noAuthentication = NoAuthentication('No authentication services configured')
 
+
 class AuthenticationError(ErrorIndication):
     pass
 
+
 authenticationError = AuthenticationError('Ciphering services not available or bad parameters')
 
+
 class AuthenticationFailure(ErrorIndication):
     pass
 
+
 authenticationFailure = AuthenticationFailure('Authenticator mismatched')
 
+
 class UnsupportedAuthProtocol(ErrorIndication):
     pass
 
+
 unsupportedAuthProtocol = UnsupportedAuthProtocol('Authentication protocol is not supprted')
 
+
 class UnsupportedPrivProtocol(ErrorIndication):
     pass
 
+
 unsupportedPrivProtocol = UnsupportedPrivProtocol('Privacy protocol is not supprted')
 
+
 class UnknownSecurityName(ErrorIndication):
     pass
 
+
 unknownSecurityName = UnknownSecurityName('Unknown SNMP security name encountered')
 
+
 class UnsupportedSecurityModel(ErrorIndication):
     pass
 
+
 unsupportedSecurityModel = UnsupportedSecurityModel('Unsupported SNMP security model')
 
+
 class UnsupportedSecurityLevel(ErrorIndication):
     pass
 
+
 unsupportedSecurityLevel = UnsupportedSecurityLevel('Unsupported SNMP security level')
 
+
 class NotInTimeWindow(ErrorIndication):
     pass
 
+
 notInTimeWindow = NotInTimeWindow('SNMP message timing parameters not in windows of trust')
 
+
 # SNMP access-control errors
 
 class NoSuchView(ErrorIndication):
     pass
 
+
 noSuchView = NoSuchView('No such MIB view currently exists')
 
+
 class NoAccessEntry(ErrorIndication):
     pass
 
+
 noAccessEntry = NoAccessEntry('Access to MIB node denined')
 
+
 class NoGroupName(ErrorIndication):
     pass
 
+
 noGroupName = NoGroupName('No such VACM group configured')
 
+
 class NoSuchContext(ErrorIndication):
     pass
 
+
 noSuchContext = NoSuchContext('SNMP context now found')
 
+
 class NotInView(ErrorIndication):
     pass
 
+
 notInView = NotInView('Requested OID is out of MIB view')
 
+
 class AccessAllowed(ErrorIndication):
     pass
 
+
 accessAllowed = AccessAllowed()
 
+
 class OtherError(ErrorIndication):
     pass
 
+
 otherError = OtherError('Unspecified SNMP engine error occurred')
 
+
 # SNMP Apps errors
 
 class OidNotIncreasing(ErrorIndication):
     pass
 
+
 oidNotIncreasing = OidNotIncreasing('OIDs are not increasing')
diff --git a/pysnmp/proto/error.py b/pysnmp/proto/error.py
index b83def84..5abcdabd 100644
--- a/pysnmp/proto/error.py
+++ b/pysnmp/proto/error.py
@@ -8,19 +8,23 @@ from pyasn1.error import PyAsn1Error
 from pysnmp.error import PySnmpError
 from pysnmp import debug
 
+
 class ProtocolError(PySnmpError, PyAsn1Error):
     pass
 
+
 # SNMP v3 exceptions
 
 class SnmpV3Error(ProtocolError):
     pass
 
+
 class StatusInformation(SnmpV3Error):
     def __init__(self, **kwargs):
         SnmpV3Error.__init__(self)
         self.__errorIndication = kwargs
-        debug.logger & (debug.flagDsp|debug.flagMP|debug.flagSM|debug.flagACL) and debug.logger('StatusInformation: %s' % kwargs)
+        debug.logger & (debug.flagDsp | debug.flagMP | debug.flagSM | debug.flagACL) and debug.logger(
+            'StatusInformation: %s' % kwargs)
 
     def __str__(self):
         return str(self.__errorIndication)
@@ -34,14 +38,18 @@ class StatusInformation(SnmpV3Error):
     def get(self, key, defVal=None):
         return self.__errorIndication.get(key, defVal)
 
+
 class CacheExpiredError(SnmpV3Error):
     pass
 
+
 class InternalError(SnmpV3Error):
     pass
 
+
 class MessageProcessingError(SnmpV3Error):
     pass
 
+
 class RequestTimeout(SnmpV3Error):
     pass
diff --git a/pysnmp/proto/rfc1155.py b/pysnmp/proto/rfc1155.py
index 88939307..fa7ab552 100644
--- a/pysnmp/proto/rfc1155.py
+++ b/pysnmp/proto/rfc1155.py
@@ -11,11 +11,12 @@ from pysnmp.proto import error
 __all__ = ['Opaque', 'NetworkAddress', 'ObjectName', 'TimeTicks',
            'Counter', 'Gauge', 'IpAddress']
 
+
 class IpAddress(univ.OctetString):
     tagSet = univ.OctetString.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x00)
     )
-    subtypeSpec = univ.OctetString.subtypeSpec+constraint.ValueSizeConstraint(
+    subtypeSpec = univ.OctetString.subtypeSpec + constraint.ValueSizeConstraint(
         4, 4
     )
 
@@ -24,7 +25,7 @@ class IpAddress(univ.OctetString):
             try:
                 value = [int(x) for x in value.split('.')]
             except:
-                raise error.ProtocolError('Bad IP address syntax %s' %  value)
+                raise error.ProtocolError('Bad IP address syntax %s' % value)
         if len(value) != 4:
             raise error.ProtocolError('Bad IP address syntax')
         return univ.OctetString.prettyIn(self, value)
@@ -35,44 +36,51 @@ class IpAddress(univ.OctetString):
         else:
             return ''
 
+
 class Counter(univ.Integer):
     tagSet = univ.Integer.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x01)
     )
-    subtypeSpec = univ.Integer.subtypeSpec+constraint.ValueRangeConstraint(
+    subtypeSpec = univ.Integer.subtypeSpec + constraint.ValueRangeConstraint(
         0, 4294967295
     )
 
+
 class NetworkAddress(univ.Choice):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('internet', IpAddress())
     )
 
+
 class Gauge(univ.Integer):
     tagSet = univ.Integer.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x02)
     )
-    subtypeSpec = univ.Integer.subtypeSpec+constraint.ValueRangeConstraint(
+    subtypeSpec = univ.Integer.subtypeSpec + constraint.ValueRangeConstraint(
         0, 4294967295
     )
 
+
 class TimeTicks(univ.Integer):
     tagSet = univ.Integer.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x03)
     )
-    subtypeSpec = univ.Integer.subtypeSpec+constraint.ValueRangeConstraint(
+    subtypeSpec = univ.Integer.subtypeSpec + constraint.ValueRangeConstraint(
         0, 4294967295
     )
 
+
 class Opaque(univ.OctetString):
     tagSet = univ.OctetString.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x04)
     )
 
+
 class ObjectName(univ.ObjectIdentifier):
     pass
 
-class TypeCoercionHackMixIn: # XXX
+
+class TypeCoercionHackMixIn:  # XXX
     # Reduce ASN1 type check to simple tag check as SMIv2 objects may
     # not be constraints-compatible with those used in SNMP PDU.
     def _verifyComponent(self, idx, value, **kwargs):
@@ -84,6 +92,7 @@ class TypeCoercionHackMixIn: # XXX
             if not t.getTagSet().isSuperTagSetOf(value.getTagSet()):
                 raise PyAsn1Error('Component type error %r vs %r' % (t, value))
 
+
 class SimpleSyntax(TypeCoercionHackMixIn, univ.Choice):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('number', univ.Integer()),
@@ -92,6 +101,7 @@ class SimpleSyntax(TypeCoercionHackMixIn, univ.Choice):
         namedtype.NamedType('empty', univ.Null())
     )
 
+
 class ApplicationSyntax(TypeCoercionHackMixIn, univ.Choice):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('address', NetworkAddress()),
@@ -101,6 +111,7 @@ class ApplicationSyntax(TypeCoercionHackMixIn, univ.Choice):
         namedtype.NamedType('arbitrary', Opaque())
     )
 
+
 class ObjectSyntax(univ.Choice):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('simple', SimpleSyntax()),
diff --git a/pysnmp/proto/rfc1157.py b/pysnmp/proto/rfc1157.py
index 97b4215a..0b04747c 100644
--- a/pysnmp/proto/rfc1157.py
+++ b/pysnmp/proto/rfc1157.py
@@ -10,15 +10,22 @@ from pysnmp.proto import rfc1155
 __all__ = ['GetNextRequestPDU', 'GetResponsePDU', 'SetRequestPDU',
            'TrapPDU', 'GetRequestPDU']
 
+
 class VarBind(univ.Sequence):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('name', rfc1155.ObjectName()),
         namedtype.NamedType('value', rfc1155.ObjectSyntax())
     )
+
+
 class VarBindList(univ.SequenceOf):
     componentType = VarBind()
 
-errorStatus = univ.Integer(namedValues=namedval.NamedValues(('noError', 0), ('tooBig', 1), ('noSuchName', 2), ('badValue', 3), ('readOnly', 4), ('genErr', 5)))
+
+errorStatus = univ.Integer(
+    namedValues=namedval.NamedValues(('noError', 0), ('tooBig', 1), ('noSuchName', 2),
+                                     ('badValue', 3), ('readOnly', 4), ('genErr', 5)))
+
 
 class _RequestBase(univ.Sequence):
     componentType = namedtype.NamedTypes(
@@ -28,24 +35,35 @@ class _RequestBase(univ.Sequence):
         namedtype.NamedType('variable-bindings', VarBindList())
     )
 
+
 class GetRequestPDU(_RequestBase):
     tagSet = _RequestBase.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, 0)
     )
+
+
 class GetNextRequestPDU(_RequestBase):
     tagSet = _RequestBase.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, 1)
     )
+
+
 class GetResponsePDU(_RequestBase):
     tagSet = _RequestBase.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, 2)
     )
+
+
 class SetRequestPDU(_RequestBase):
     tagSet = _RequestBase.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, 3)
     )
 
-genericTrap = univ.Integer().clone(namedValues=namedval.NamedValues(('coldStart', 0), ('warmStart', 1), ('linkDown', 2), ('linkUp', 3), ('authenticationFailure', 4), ('egpNeighborLoss', 5), ('enterpriseSpecific', 6)))
+
+genericTrap = univ.Integer().clone(
+    namedValues=namedval.NamedValues(('coldStart', 0), ('warmStart', 1), ('linkDown', 2), ('linkUp', 3),
+                                     ('authenticationFailure', 4), ('egpNeighborLoss', 5), ('enterpriseSpecific', 6)))
+
 
 class TrapPDU(univ.Sequence):
     tagSet = univ.Sequence.tagSet.tagImplicitly(
@@ -60,6 +78,7 @@ class TrapPDU(univ.Sequence):
         namedtype.NamedType('variable-bindings', VarBindList())
     )
 
+
 class PDUs(univ.Choice):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('get-request', GetRequestPDU()),
@@ -69,8 +88,10 @@ class PDUs(univ.Choice):
         namedtype.NamedType('trap', TrapPDU())
     )
 
+
 version = univ.Integer(namedValues=namedval.NamedValues(('version-1', 0)))
 
+
 class Message(univ.Sequence):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('version', version),
diff --git a/pysnmp/proto/rfc1901.py b/pysnmp/proto/rfc1901.py
index ca72301b..01272a91 100644
--- a/pysnmp/proto/rfc1901.py
+++ b/pysnmp/proto/rfc1901.py
@@ -9,6 +9,7 @@ from pysnmp.proto import rfc1905
 
 version = univ.Integer(namedValues=namedval.NamedValues(('version-2c', 1)))
 
+
 class Message(univ.Sequence):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('version', version),
diff --git a/pysnmp/proto/rfc1902.py b/pysnmp/proto/rfc1902.py
index 3b69218b..5f28f986 100644
--- a/pysnmp/proto/rfc1902.py
+++ b/pysnmp/proto/rfc1902.py
@@ -13,6 +13,7 @@ __all__ = ['Opaque', 'TimeTicks', 'Bits', 'Integer', 'OctetString',
            'IpAddress', 'Counter64', 'Unsigned32', 'Gauge32', 'Integer32',
            'ObjectIdentifier', 'Counter32']
 
+
 class Integer32(univ.Integer):
     """Creates an instance of SNMP Integer32 class.
 
@@ -55,7 +56,7 @@ class Integer32(univ.Integer):
         >>>
 
     """
-    subtypeSpec = univ.Integer.subtypeSpec+constraint.ValueRangeConstraint(
+    subtypeSpec = univ.Integer.subtypeSpec + constraint.ValueRangeConstraint(
         -2147483648, 2147483647
     )
 
@@ -63,8 +64,10 @@ class Integer32(univ.Integer):
     def withValues(cls, *values):
         """Creates a subclass with discreet values constraint.
         """
+
         class X(cls):
             subtypeSpec = cls.subtypeSpec + constraint.SingleValueConstraint(*values)
+
         X.__name__ = cls.__name__
         return X
 
@@ -72,11 +75,14 @@ class Integer32(univ.Integer):
     def withRange(cls, minimum, maximum):
         """Creates a subclass with value range constraint.
         """
+
         class X(cls):
             subtypeSpec = cls.subtypeSpec + constraint.ValueRangeConstraint(minimum, maximum)
+
         X.__name__ = cls.__name__
         return X
 
+
 class Integer(Integer32):
     """Creates an instance of SNMP INTEGER class.
 
@@ -120,16 +126,20 @@ class Integer(Integer32):
         >>>
 
     """
+
     @classmethod
     def withNamedValues(cls, **values):
         """Creates a subclass with discreet named values constraint.
         """
+
         class X(cls):
             namedValues = cls.namedValues + namedval.NamedValues(*values.items())
             subtypeSpec = cls.subtypeSpec + constraint.SingleValueConstraint(*values.values())
+
         X.__name__ = cls.__name__
         return X
 
+
 class OctetString(univ.OctetString):
     """Creates an instance of SNMP OCTET STRING class.
 
@@ -169,7 +179,7 @@ class OctetString(univ.OctetString):
         >>>
 
     """
-    subtypeSpec = univ.OctetString.subtypeSpec+constraint.ValueSizeConstraint(
+    subtypeSpec = univ.OctetString.subtypeSpec + constraint.ValueSizeConstraint(
         0, 65535
     )
 
@@ -205,8 +215,10 @@ class OctetString(univ.OctetString):
     def withSize(cls, minimum, maximum):
         """Creates a subclass with value size constraint.
         """
+
         class X(cls):
             subtypeSpec = cls.subtypeSpec + constraint.ValueSizeConstraint(minimum, maximum)
+
         X.__name__ = cls.__name__
         return X
 
@@ -222,6 +234,7 @@ class OctetString(univ.OctetString):
         else:
             return octets.octs2str(value)
 
+
 class ObjectIdentifier(univ.ObjectIdentifier):
     """Creates an instance of SNMP OBJECT IDENTIFIER class.
 
@@ -256,6 +269,7 @@ class ObjectIdentifier(univ.ObjectIdentifier):
 
     """
 
+
 class IpAddress(OctetString):
     """Creates an instance of SNMP IpAddress class.
 
@@ -289,7 +303,7 @@ class IpAddress(OctetString):
     tagSet = OctetString.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x00)
     )
-    subtypeSpec = OctetString.subtypeSpec+constraint.ValueSizeConstraint(
+    subtypeSpec = OctetString.subtypeSpec + constraint.ValueSizeConstraint(
         4, 4
     )
     fixedLength = 4
@@ -299,7 +313,7 @@ class IpAddress(OctetString):
             try:
                 value = [int(x) for x in value.split('.')]
             except:
-                raise error.ProtocolError('Bad IP address syntax %s' %  value)
+                raise error.ProtocolError('Bad IP address syntax %s' % value)
         value = OctetString.prettyIn(self, value)
         if len(value) != 4:
             raise error.ProtocolError('Bad IP address syntax')
@@ -313,6 +327,7 @@ class IpAddress(OctetString):
         else:
             return ''
 
+
 class Counter32(univ.Integer):
     """Creates an instance of SNMP Counter32 class.
 
@@ -347,10 +362,11 @@ class Counter32(univ.Integer):
     tagSet = univ.Integer.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x01)
     )
-    subtypeSpec = univ.Integer.subtypeSpec+constraint.ValueRangeConstraint(
+    subtypeSpec = univ.Integer.subtypeSpec + constraint.ValueRangeConstraint(
         0, 4294967295
     )
 
+
 class Gauge32(univ.Integer):
     """Creates an instance of SNMP Gauge32 class.
 
@@ -385,10 +401,11 @@ class Gauge32(univ.Integer):
     tagSet = univ.Integer.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x02)
     )
-    subtypeSpec = univ.Integer.subtypeSpec+constraint.ValueRangeConstraint(
+    subtypeSpec = univ.Integer.subtypeSpec + constraint.ValueRangeConstraint(
         0, 4294967295
     )
 
+
 class Unsigned32(univ.Integer):
     """Creates an instance of SNMP Unsigned32 class.
 
@@ -422,10 +439,11 @@ class Unsigned32(univ.Integer):
     tagSet = univ.Integer.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x02)
     )
-    subtypeSpec = univ.Integer.subtypeSpec+constraint.ValueRangeConstraint(
+    subtypeSpec = univ.Integer.subtypeSpec + constraint.ValueRangeConstraint(
         0, 4294967295
     )
 
+
 class TimeTicks(univ.Integer):
     """Creates an instance of SNMP TimeTicks class.
 
@@ -459,10 +477,11 @@ class TimeTicks(univ.Integer):
     tagSet = univ.Integer.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x03)
     )
-    subtypeSpec = univ.Integer.subtypeSpec+constraint.ValueRangeConstraint(
+    subtypeSpec = univ.Integer.subtypeSpec + constraint.ValueRangeConstraint(
         0, 4294967295
     )
 
+
 class Opaque(univ.OctetString):
     """Creates an instance of SNMP Opaque class.
 
@@ -507,6 +526,7 @@ class Opaque(univ.OctetString):
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x04)
     )
 
+
 class Counter64(univ.Integer):
     """Creates an instance of SNMP Counter64 class.
 
@@ -541,10 +561,11 @@ class Counter64(univ.Integer):
     tagSet = univ.Integer.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x06)
     )
-    subtypeSpec = univ.Integer.subtypeSpec+constraint.ValueRangeConstraint(
+    subtypeSpec = univ.Integer.subtypeSpec + constraint.ValueRangeConstraint(
         0, 18446744073709551615
     )
 
+
 class Bits(OctetString):
     """Creates an instance of SNMP BITS class.
 
@@ -595,6 +616,7 @@ class Bits(OctetString):
 
     """
     namedValues = namedval.NamedValues()
+
     def __init__(self, value=None, tagSet=None, subtypeSpec=None,
                  encoding=None, binValue=None, hexValue=None,
                  namedValues=None):
@@ -608,19 +630,19 @@ class Bits(OctetString):
 
     def prettyIn(self, bits):
         if not isinstance(bits, (tuple, list)):
-            return OctetString.prettyIn(self, bits) # raw bitstring
-        octets = []
-        for bit in bits: # tuple of named bits
+            return OctetString.prettyIn(self, bits)  # raw bitstring
+        _octets = []
+        for bit in bits:  # tuple of named bits
             v = self.__namedValues.getValue(bit)
             if v is None:
                 raise error.ProtocolError(
                     'Unknown named bit %s' % bit
-                    )
+                )
             d, m = divmod(v, 8)
-            if d >= len(octets):
-                octets.extend([0] * (d - len(octets) + 1))
-            octets[d] = octets[d] | 0x01 << (7-m)
-        return OctetString.prettyIn(self, octets)
+            if d >= len(_octets):
+                _octets.extend([0] * (d - len(_octets) + 1))
+            _octets[d] |= 0x01 << (7 - m)
+        return OctetString.prettyIn(self, _octets)
 
     def prettyOut(self, value):
         names = []
@@ -630,10 +652,10 @@ class Bits(OctetString):
             v = ints[i]
             j = 7
             while j >= 0:
-                if v & (0x01<<j):
-                    name = self.__namedValues.getName(i*8+7-j)
+                if v & (0x01 << j):
+                    name = self.__namedValues.getName(i * 8 + 7 - j)
                     if name is None:
-                        name = 'UnknownBit-%s' % (i*8+7-j,)
+                        name = 'UnknownBit-%s' % (i * 8 + 7 - j,)
                     names.append(name)
                 j -= 1
             i += 1
@@ -643,7 +665,7 @@ class Bits(OctetString):
               encoding=None, binValue=None, hexValue=None,
               namedValues=None):
         if value is None and tagSet is None and subtypeSpec is None \
-               and namedValues is None:
+                and namedValues is None:
             return self
         if value is None:
             value = self._value
@@ -681,8 +703,10 @@ class Bits(OctetString):
     def withNamedBits(cls, **values):
         """Creates a subclass with discreet named bits constraint.
         """
+
         class X(cls):
             namedValues = cls.namedValues + namedval.NamedValues(*values.items())
+
         X.__name__ = cls.__name__
         return X
 
@@ -690,6 +714,7 @@ class Bits(OctetString):
 class ObjectName(univ.ObjectIdentifier):
     pass
 
+
 class SimpleSyntax(rfc1155.TypeCoercionHackMixIn, univ.Choice):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('integer-value', Integer()),
@@ -697,6 +722,7 @@ class SimpleSyntax(rfc1155.TypeCoercionHackMixIn, univ.Choice):
         namedtype.NamedType('objectID-value', univ.ObjectIdentifier())
     )
 
+
 class ApplicationSyntax(rfc1155.TypeCoercionHackMixIn, univ.Choice):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('ipAddress-value', IpAddress()),
@@ -705,9 +731,10 @@ class ApplicationSyntax(rfc1155.TypeCoercionHackMixIn, univ.Choice):
         namedtype.NamedType('arbitrary-value', Opaque()),
         namedtype.NamedType('big-counter-value', Counter64()),
         # This conflicts with Counter32
-        #namedtype.NamedType('unsigned-integer-value', Unsigned32()),
+        # namedtype.NamedType('unsigned-integer-value', Unsigned32()),
         namedtype.NamedType('gauge32-value', Gauge32())
-    ) # BITS misplaced?
+    )  # BITS misplaced?
+
 
 class ObjectSyntax(univ.Choice):
     componentType = namedtype.NamedTypes(
diff --git a/pysnmp/proto/rfc1905.py b/pysnmp/proto/rfc1905.py
index 0b7136a8..d346e468 100644
--- a/pysnmp/proto/rfc1905.py
+++ b/pysnmp/proto/rfc1905.py
@@ -21,6 +21,7 @@ max_bindings = rfc1902.Integer(2147483647)
 UnSpecified = univ.Null
 unSpecified = UnSpecified()
 
+
 class NoSuchObject(univ.Null):
     tagSet = univ.Null.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0x00)
@@ -29,8 +30,10 @@ class NoSuchObject(univ.Null):
     def prettyPrint(self, scope=0):
         return 'No Such Object currently exists at this OID'
 
+
 noSuchObject = NoSuchObject()
 
+
 class NoSuchInstance(univ.Null):
     tagSet = univ.Null.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0x01)
@@ -38,8 +41,11 @@ class NoSuchInstance(univ.Null):
 
     def prettyPrint(self, scope=0):
         return 'No Such Instance currently exists at this OID'
+
+
 noSuchInstance = NoSuchInstance()
 
+
 class EndOfMibView(univ.Null):
     tagSet = univ.Null.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0x02)
@@ -48,8 +54,10 @@ class EndOfMibView(univ.Null):
     def prettyPrint(self, scope=0):
         return 'No more variables left in this MIB View'
 
+
 endOfMibView = EndOfMibView()
 
+
 # Made a separate class for better readability
 class _BindValue(univ.Choice):
     componentType = namedtype.NamedTypes(
@@ -60,32 +68,45 @@ class _BindValue(univ.Choice):
         namedtype.NamedType('endOfMibView', endOfMibView)
     )
 
+
 class VarBind(univ.Sequence):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('name', rfc1902.ObjectName()),
         namedtype.NamedType('', _BindValue())
     )
 
+
 class VarBindList(univ.SequenceOf):
     componentType = VarBind()
     subtypeSpec = univ.SequenceOf.subtypeSpec + constraint.ValueSizeConstraint(
         0, max_bindings
     )
 
-errorStatus = univ.Integer(namedValues=namedval.NamedValues(('noError', 0), ('tooBig', 1), ('noSuchName', 2), ('badValue', 3), ('readOnly', 4), ('genErr', 5), ('noAccess', 6), ('wrongType', 7), ('wrongLength', 8), ('wrongEncoding', 9), ('wrongValue', 10), ('noCreation', 11), ('inconsistentValue', 12), ('resourceUnavailable', 13), ('commitFailed', 14), ('undoFailed', 15), ('authorizationError', 16), ('notWritable', 17), ('inconsistentName', 18)))
+
+errorStatus = univ.Integer(
+    namedValues=namedval.NamedValues(('noError', 0), ('tooBig', 1), ('noSuchName', 2), ('badValue', 3), ('readOnly', 4),
+                                     ('genErr', 5), ('noAccess', 6), ('wrongType', 7), ('wrongLength', 8),
+                                     ('wrongEncoding', 9), ('wrongValue', 10), ('noCreation', 11),
+                                     ('inconsistentValue', 12), ('resourceUnavailable', 13), ('commitFailed', 14),
+                                     ('undoFailed', 15), ('authorizationError', 16), ('notWritable', 17),
+                                     ('inconsistentName', 18)))
+
 
 # Base class for a non-bulk PDU
 class PDU(univ.Sequence):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('request-id', rfc1902.Integer32()),
         namedtype.NamedType('error-status', errorStatus),
-        namedtype.NamedType('error-index', univ.Integer().subtype(subtypeSpec=constraint.ValueRangeConstraint(0, max_bindings))),
+        namedtype.NamedType('error-index',
+                            univ.Integer().subtype(subtypeSpec=constraint.ValueRangeConstraint(0, max_bindings))),
         namedtype.NamedType('variable-bindings', VarBindList())
     )
 
+
 nonRepeaters = univ.Integer().subtype(subtypeSpec=constraint.ValueRangeConstraint(0, max_bindings))
 maxRepetitions = univ.Integer().subtype(subtypeSpec=constraint.ValueRangeConstraint(0, max_bindings))
 
+
 # Base class for bulk PDU
 class BulkPDU(univ.Sequence):
     componentType = namedtype.NamedTypes(
@@ -95,46 +116,55 @@ class BulkPDU(univ.Sequence):
         namedtype.NamedType('variable-bindings', VarBindList())
     )
 
+
 class GetRequestPDU(PDU):
     tagSet = PDU.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, 0)
     )
 
+
 class GetNextRequestPDU(PDU):
     tagSet = PDU.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, 1)
     )
 
+
 class ResponsePDU(PDU):
     tagSet = PDU.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, 2)
     )
 
+
 class SetRequestPDU(PDU):
     tagSet = PDU.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, 3)
     )
 
+
 class GetBulkRequestPDU(BulkPDU):
     tagSet = PDU.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, 5)
     )
 
+
 class InformRequestPDU(PDU):
     tagSet = PDU.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, 6)
     )
 
+
 class SNMPv2TrapPDU(PDU):
     tagSet = PDU.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, 7)
     )
 
+
 class ReportPDU(PDU):
     tagSet = PDU.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, 8)
     )
 
+
 class PDUs(univ.Choice):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('get-request', GetRequestPDU()),
diff --git a/pysnmp/proto/rfc3412.py b/pysnmp/proto/rfc3412.py
index cfe01288..9feab6e3 100644
--- a/pysnmp/proto/rfc3412.py
+++ b/pysnmp/proto/rfc3412.py
@@ -8,14 +8,16 @@ import sys
 from pyasn1.compat.octets import null
 from pysnmp.smi import builder, instrum
 from pysnmp.proto import errind, error, cache
-from pysnmp.proto.api import verdec # XXX
+from pysnmp.proto.api import verdec  # XXX
 from pysnmp.error import PySnmpError
 from pysnmp import nextid, debug
 
+
 class MsgAndPduDispatcher:
     """SNMP engine PDU & message dispatcher. Exchanges SNMP PDU's with
        applications and serialized messages with transport level.
     """
+
     def __init__(self, mibInstrumController=None):
         if mibInstrumController is None:
             self.mibInstrumController = instrum.MibInstrumController(
@@ -68,7 +70,8 @@ class MsgAndPduDispatcher:
             # 4.3.4
             self.__appsRegistration[k] = processPdu
 
-        debug.logger & debug.flagDsp and debug.logger('registerContextEngineId: contextEngineId %r pduTypes %s' % (contextEngineId, pduTypes))
+        debug.logger & debug.flagDsp and debug.logger(
+            'registerContextEngineId: contextEngineId %r pduTypes %s' % (contextEngineId, pduTypes))
 
     # 4.4.1
     def unregisterContextEngineId(self, contextEngineId, pduTypes):
@@ -76,14 +79,16 @@ class MsgAndPduDispatcher:
         # 4.3.4
         if contextEngineId is None:
             # Default to local snmpEngineId
-            contextEngineId, = self.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')
+            contextEngineId, = self.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB',
+                                                                                  'snmpEngineID')
 
         for pduType in pduTypes:
             k = (contextEngineId, pduType)
             if k in self.__appsRegistration:
                 del self.__appsRegistration[k]
 
-        debug.logger & debug.flagDsp and debug.logger('unregisterContextEngineId: contextEngineId %r pduTypes %s' % (contextEngineId, pduTypes))
+        debug.logger & debug.flagDsp and debug.logger(
+            'unregisterContextEngineId: contextEngineId %r pduTypes %s' % (contextEngineId, pduTypes))
 
     def getRegisteredApp(self, contextEngineId, pduType):
         k = (contextEngineId, pduType)
@@ -91,7 +96,7 @@ class MsgAndPduDispatcher:
             return self.__appsRegistration[k]
         k = (null, pduType)
         if k in self.__appsRegistration:
-            return self.__appsRegistration[k] # wildcard
+            return self.__appsRegistration[k]  # wildcard
 
     # Dispatcher <-> application API
 
@@ -112,7 +117,8 @@ class MsgAndPduDispatcher:
                 errorIndication=errind.unsupportedMsgProcessingModel
             )
 
-        debug.logger & debug.flagDsp and debug.logger('sendPdu: securityName %s, PDU\n%s' % (securityName, PDU.prettyPrint()))
+        debug.logger & debug.flagDsp and debug.logger(
+            'sendPdu: securityName %s, PDU\n%s' % (securityName, PDU.prettyPrint()))
 
         # 4.1.1.3
         sendPduHandle = self.__sendPduHandle()
@@ -121,14 +127,16 @@ class MsgAndPduDispatcher:
                 sendPduHandle,
                 messageProcessingModel=messageProcessingModel,
                 sendPduHandle=sendPduHandle,
-                timeout=timeout+snmpEngine.transportDispatcher.getTimerTicks(),
+                timeout=timeout + snmpEngine.transportDispatcher.getTimerTicks(),
                 cbFun=cbFun,
                 cbCtx=cbCtx
             )
 
-            debug.logger & debug.flagDsp and debug.logger('sendPdu: current time %d ticks, one tick is %s seconds' % (snmpEngine.transportDispatcher.getTimerTicks(), snmpEngine.transportDispatcher.getTimerResolution()))
+            debug.logger & debug.flagDsp and debug.logger('sendPdu: current time %d ticks, one tick is %s seconds' % (
+                snmpEngine.transportDispatcher.getTimerTicks(), snmpEngine.transportDispatcher.getTimerResolution()))
 
-        debug.logger & debug.flagDsp and debug.logger('sendPdu: new sendPduHandle %s, timeout %s ticks, cbFun %s' % (sendPduHandle, timeout, cbFun))
+        debug.logger & debug.flagDsp and debug.logger(
+            'sendPdu: new sendPduHandle %s, timeout %s ticks, cbFun %s' % (sendPduHandle, timeout, cbFun))
 
         origTransportDomain = transportDomain
         origTransportAddress = transportAddress
@@ -138,11 +146,11 @@ class MsgAndPduDispatcher:
             (transportDomain,
              transportAddress,
              outgoingMessage) = mpHandler.prepareOutgoingMessage(
-                 snmpEngine, origTransportDomain, origTransportAddress,
-                 messageProcessingModel, securityModel, securityName,
-                 securityLevel, contextEngineId, contextName,
-                 pduVersion, PDU, expectResponse, sendPduHandle
-             )
+                snmpEngine, origTransportDomain, origTransportAddress,
+                messageProcessingModel, securityModel, securityName,
+                securityLevel, contextEngineId, contextName,
+                pduVersion, PDU, expectResponse, sendPduHandle
+            )
 
             debug.logger & debug.flagDsp and debug.logger('sendPdu: MP succeeded')
         except PySnmpError:
@@ -213,18 +221,19 @@ class MsgAndPduDispatcher:
                 errorIndication=errind.unsupportedMsgProcessingModel
             )
 
-        debug.logger & debug.flagDsp and debug.logger('returnResponsePdu: PDU %s' % (PDU and PDU.prettyPrint() or "<empty>",))
+        debug.logger & debug.flagDsp and debug.logger(
+            'returnResponsePdu: PDU %s' % (PDU and PDU.prettyPrint() or "<empty>",))
 
         # 4.1.2.2
         try:
             (transportDomain,
              transportAddress,
              outgoingMessage) = mpHandler.prepareResponseMessage(
-                 snmpEngine, messageProcessingModel, securityModel,
-                 securityName, securityLevel, contextEngineId, contextName,
-                 pduVersion, PDU, maxSizeResponseScopedPDU, stateReference,
-                 statusInformation
-             )
+                snmpEngine, messageProcessingModel, securityModel,
+                securityName, securityLevel, contextEngineId, contextName,
+                pduVersion, PDU, maxSizeResponseScopedPDU, stateReference,
+                statusInformation
+            )
 
             debug.logger & debug.flagDsp and debug.logger('returnResponsePdu: MP suceeded')
 
@@ -233,9 +242,10 @@ class MsgAndPduDispatcher:
             raise
 
         # Handle oversized messages XXX transport constrains?
-        snmpEngineMaxMessageSize, = self.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineMaxMessageSize')
+        snmpEngineMaxMessageSize, = self.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB',
+                                                                                       'snmpEngineMaxMessageSize')
         if snmpEngineMaxMessageSize.syntax and \
-               len(outgoingMessage) > snmpEngineMaxMessageSize.syntax:
+                len(outgoingMessage) > snmpEngineMaxMessageSize.syntax:
             snmpSilentDrops, = self.mibInstrumController.mibBuilder.importSymbols('__SNMPv2-MIB', 'snmpSilentDrops')
             snmpSilentDrops.syntax += 1
             raise error.StatusInformation(errorIndication=errind.tooBig)
@@ -271,15 +281,16 @@ class MsgAndPduDispatcher:
         # 4.2.1.1
         snmpInPkts, = self.mibInstrumController.mibBuilder.importSymbols(
             '__SNMPv2-MIB', 'snmpInPkts'
-            )
+        )
         snmpInPkts.syntax += 1
 
         # 4.2.1.2
         try:
-            restOfWholeMsg = null # XXX fix decoder non-recursive return
+            restOfWholeMsg = null  # XXX fix decoder non-recursive return
             msgVersion = verdec.decodeMessageVersion(wholeMsg)
         except error.ProtocolError:
-            snmpInASNParseErrs, = self.mibInstrumController.mibBuilder.importSymbols('__SNMPv2-MIB', 'snmpInASNParseErrs')
+            snmpInASNParseErrs, = self.mibInstrumController.mibBuilder.importSymbols('__SNMPv2-MIB',
+                                                                                     'snmpInASNParseErrs')
             snmpInASNParseErrs.syntax += 1
             return null  # n.b the whole buffer gets dropped
 
@@ -304,8 +315,8 @@ class MsgAndPduDispatcher:
              pduVersion, PDU, pduType, sendPduHandle,
              maxSizeResponseScopedPDU, statusInformation,
              stateReference) = mpHandler.prepareDataElements(
-                 snmpEngine, transportDomain, transportAddress, wholeMsg
-             )
+                snmpEngine, transportDomain, transportAddress, wholeMsg
+            )
 
             debug.logger & debug.flagDsp and debug.logger('receiveMessage: MP succeded')
 
@@ -314,7 +325,8 @@ class MsgAndPduDispatcher:
             if 'sendPduHandle' in statusInformation:
                 # Dropped REPORT -- re-run pending reqs queue as some
                 # of them may be waiting for this REPORT
-                debug.logger & debug.flagDsp and debug.logger('receiveMessage: MP failed, statusInformation %s, forcing a retry' % statusInformation)
+                debug.logger & debug.flagDsp and debug.logger(
+                    'receiveMessage: MP failed, statusInformation %s, forcing a retry' % statusInformation)
                 self.__expireRequest(
                     statusInformation['sendPduHandle'],
                     self.__cache.pop(statusInformation['sendPduHandle']),
@@ -336,7 +348,8 @@ class MsgAndPduDispatcher:
             # 4.2.2.1.2
             if processPdu is None:
                 # 4.2.2.1.2.a
-                snmpUnknownPDUHandlers, = self.mibInstrumController.mibBuilder.importSymbols('__SNMP-MPD-MIB', 'snmpUnknownPDUHandlers')
+                snmpUnknownPDUHandlers, = self.mibInstrumController.mibBuilder.importSymbols('__SNMP-MPD-MIB',
+                                                                                             'snmpUnknownPDUHandlers')
                 snmpUnknownPDUHandlers.syntax += 1
 
                 # 4.2.2.1.2.b
@@ -354,15 +367,16 @@ class MsgAndPduDispatcher:
                     (destTransportDomain,
                      destTransportAddress,
                      outgoingMessage) = mpHandler.prepareResponseMessage(
-                         snmpEngine, messageProcessingModel,
-                         securityModel, securityName, securityLevel,
-                         contextEngineId, contextName, pduVersion,
-                         PDU, maxSizeResponseScopedPDU, stateReference,
-                         statusInformation
-                     )
+                        snmpEngine, messageProcessingModel,
+                        securityModel, securityName, securityLevel,
+                        contextEngineId, contextName, pduVersion,
+                        PDU, maxSizeResponseScopedPDU, stateReference,
+                        statusInformation
+                    )
 
                 except error.StatusInformation:
-                    debug.logger & debug.flagDsp and debug.logger('receiveMessage: report failed, statusInformation %s' % sys.exc_info()[1])
+                    debug.logger & debug.flagDsp and debug.logger(
+                        'receiveMessage: report failed, statusInformation %s' % sys.exc_info()[1])
                     return restOfWholeMsg
 
                 # 4.2.2.1.2.c
@@ -372,7 +386,7 @@ class MsgAndPduDispatcher:
                         destTransportAddress
                     )
 
-                except PySnmpError: # XXX
+                except PySnmpError:  # XXX
                     pass
 
                 debug.logger & debug.flagDsp and debug.logger('receiveMessage: reporting succeeded')
@@ -424,11 +438,13 @@ class MsgAndPduDispatcher:
 
             # 4.2.2.2.2
             if cachedParams is None:
-                snmpUnknownPDUHandlers, = self.mibInstrumController.mibBuilder.importSymbols('__SNMP-MPD-MIB', 'snmpUnknownPDUHandlers')
+                snmpUnknownPDUHandlers, = self.mibInstrumController.mibBuilder.importSymbols('__SNMP-MPD-MIB',
+                                                                                             'snmpUnknownPDUHandlers')
                 snmpUnknownPDUHandlers.syntax += 1
                 return restOfWholeMsg
 
-            debug.logger & debug.flagDsp and debug.logger('receiveMessage: cache read by sendPduHandle %s' % sendPduHandle)
+            debug.logger & debug.flagDsp and debug.logger(
+                'receiveMessage: cache read by sendPduHandle %s' % sendPduHandle)
 
             # 4.2.2.2.3
             # no-op ? XXX
@@ -476,6 +492,7 @@ class MsgAndPduDispatcher:
 
     # Cache expiration stuff
 
+    # noinspection PyUnusedLocal
     def __expireRequest(self, cacheKey, cachedParams, snmpEngine,
                         statusInformation=None):
         timeNow = snmpEngine.transportDispatcher.getTimerTicks()
@@ -504,5 +521,6 @@ class MsgAndPduDispatcher:
                            cachedParams['cbCtx'])
         return True
 
+    # noinspection PyUnusedLocal
     def receiveTimerTick(self, snmpEngine, timeNow):
         self.__cache.expire(self.__expireRequest, snmpEngine)
diff --git a/pysnmp/proto/secmod/base.py b/pysnmp/proto/secmod/base.py
index 2e4d73ed..af5ddb23 100644
--- a/pysnmp/proto/secmod/base.py
+++ b/pysnmp/proto/secmod/base.py
@@ -7,8 +7,10 @@
 from pysnmp.proto.secmod import cache
 from pysnmp.proto import error
 
+
 class AbstractSecurityModel:
     securityModelID = None
+
     def __init__(self):
         self._cache = cache.Cache()
 
diff --git a/pysnmp/proto/secmod/cache.py b/pysnmp/proto/secmod/cache.py
index b9e11821..7e6fa6df 100644
--- a/pysnmp/proto/secmod/cache.py
+++ b/pysnmp/proto/secmod/cache.py
@@ -7,8 +7,10 @@
 from pysnmp import nextid
 from pysnmp.proto import error
 
+
 class Cache:
     __stateReference = nextid.Integer(0xffffff)
+
     def __init__(self):
         self.__cacheEntries = {}
 
diff --git a/pysnmp/proto/secmod/rfc2576.py b/pysnmp/proto/secmod/rfc2576.py
index 906852fc..da5a68a8 100644
--- a/pysnmp/proto/secmod/rfc2576.py
+++ b/pysnmp/proto/secmod/rfc2576.py
@@ -13,8 +13,10 @@ from pysnmp.smi.error import NoSuchInstanceError
 from pysnmp.proto import errind, error
 from pysnmp import debug
 
+
 class SnmpV1SecurityModel(base.AbstractSecurityModel):
     securityModelID = 1
+
     # According to rfc2576, community name <-> contextEngineId/contextName
     # mapping is up to MP module for notifications but belongs to secmod
     # responsibility for other PDU types. Since I do not yet understand
@@ -26,9 +28,11 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
         base.AbstractSecurityModel.__init__(self)
 
     def _sec2com(self, snmpEngine, securityName, contextEngineId, contextName):
-        snmpTargetParamsSecurityName, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-TARGET-MIB', 'snmpTargetParamsSecurityName')
+        snmpTargetParamsSecurityName, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
+            'SNMP-TARGET-MIB', 'snmpTargetParamsSecurityName')
         if self.__paramsBranchId != snmpTargetParamsSecurityName.branchVersionId:
-            snmpTargetParamsSecurityModel, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-TARGET-MIB', 'snmpTargetParamsSecurityModel')
+            snmpTargetParamsSecurityModel, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
+                'SNMP-TARGET-MIB', 'snmpTargetParamsSecurityModel')
 
             self.__nameToModelMap = {}
 
@@ -55,14 +59,15 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
             # invalidate next map as it include this one
             self.__securityBranchId = -1
 
-        snmpCommunityName, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-COMMUNITY-MIB', 'snmpCommunityName')
+        snmpCommunityName, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-COMMUNITY-MIB',
+                                                                                                   'snmpCommunityName')
         if self.__securityBranchId != snmpCommunityName.branchVersionId:
             (snmpCommunitySecurityName,
              snmpCommunityContextEngineId,
              snmpCommunityContextName) = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
-                 'SNMP-COMMUNITY-MIB', 'snmpCommunitySecurityName',
-                 'snmpCommunityContextEngineID', 'snmpCommunityContextName'
-             )
+                'SNMP-COMMUNITY-MIB', 'snmpCommunitySecurityName',
+                'snmpCommunityContextEngineID', 'snmpCommunityContextName'
+            )
 
             self.__securityMap = {}
 
@@ -78,7 +83,8 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
 
                 _securityName = snmpCommunitySecurityName.getNode(snmpCommunitySecurityName.name + instId).syntax
 
-                _contextEngineId = snmpCommunityContextEngineId.getNode(snmpCommunityContextEngineId.name + instId).syntax
+                _contextEngineId = snmpCommunityContextEngineId.getNode(
+                    snmpCommunityContextEngineId.name + instId).syntax
 
                 _contextName = snmpCommunityContextName.getNode(snmpCommunityContextName.name + instId).syntax
 
@@ -88,7 +94,9 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
 
             self.__securityBranchId = snmpCommunityName.branchVersionId
 
-            debug.logger & debug.flagSM and debug.logger('_sec2com: built securityName to communityName map, version %s: %s' % (self.__securityBranchId, self.__securityMap))
+            debug.logger & debug.flagSM and debug.logger(
+                '_sec2com: built securityName to communityName map, version %s: %s' % (
+                    self.__securityBranchId, self.__securityMap))
 
         try:
             return self.__securityMap[(securityName,
@@ -101,13 +109,14 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
             )
 
     def _com2sec(self, snmpEngine, communityName, transportInformation):
-        snmpTargetAddrTAddress, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-TARGET-MIB', 'snmpTargetAddrTAddress')
+        snmpTargetAddrTAddress, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
+            'SNMP-TARGET-MIB', 'snmpTargetAddrTAddress')
         if self.__transportBranchId != snmpTargetAddrTAddress.branchVersionId:
             (SnmpTagValue, snmpTargetAddrTDomain,
              snmpTargetAddrTagList) = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
-                 'SNMP-TARGET-MIB', 'SnmpTagValue', 'snmpTargetAddrTDomain',
-                 'snmpTargetAddrTagList'
-              )
+                'SNMP-TARGET-MIB', 'SnmpTagValue', 'snmpTargetAddrTDomain',
+                'snmpTargetAddrTagList'
+            )
 
             self.__emptyTag = SnmpTagValue('')
 
@@ -126,10 +135,12 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
                 targetAddrTDomain = tuple(targetAddrTDomain)
 
                 if targetAddrTDomain[:len(udp.snmpUDPDomain)] == udp.snmpUDPDomain:
-                    SnmpUDPAddress, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMPv2-TM', 'SnmpUDPAddress')
+                    SnmpUDPAddress, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMPv2-TM',
+                                                                                                            'SnmpUDPAddress')
                     targetAddrTAddress = tuple(SnmpUDPAddress(targetAddrTAddress))
                 elif targetAddrTDomain[:len(udp6.snmpUDP6Domain)] == udp6.snmpUDP6Domain:
-                    TransportAddressIPv6, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('TRANSPORT-ADDRESS-MIB', 'TransportAddressIPv6')
+                    TransportAddressIPv6, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
+                        'TRANSPORT-ADDRESS-MIB', 'TransportAddressIPv6')
                     targetAddrTAddress = tuple(TransportAddressIPv6(targetAddrTAddress))
                 elif targetAddrTDomain[:len(unix.snmpLocalDomain)] == unix.snmpLocalDomain:
                     targetAddrTAddress = str(targetAddrTAddress)
@@ -147,11 +158,14 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
 
             self.__transportBranchId = snmpTargetAddrTAddress.branchVersionId
 
-            debug.logger & debug.flagSM and debug.logger('_com2sec: built transport-to-tag map version %s: %s' % (self.__transportBranchId, self.__transportToTagMap))
+            debug.logger & debug.flagSM and debug.logger('_com2sec: built transport-to-tag map version %s: %s' % (
+                self.__transportBranchId, self.__transportToTagMap))
 
-        snmpTargetParamsSecurityName, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-TARGET-MIB', 'snmpTargetParamsSecurityName')
+        snmpTargetParamsSecurityName, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
+            'SNMP-TARGET-MIB', 'snmpTargetParamsSecurityName')
         if self.__paramsBranchId != snmpTargetParamsSecurityName.branchVersionId:
-            snmpTargetParamsSecurityModel, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-TARGET-MIB', 'snmpTargetParamsSecurityModel')
+            snmpTargetParamsSecurityModel, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
+                'SNMP-TARGET-MIB', 'snmpTargetParamsSecurityModel')
 
             self.__nameToModelMap = {}
 
@@ -178,17 +192,20 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
             # invalidate next map as it include this one
             self.__communityBranchId = -1
 
-            debug.logger & debug.flagSM and debug.logger('_com2sec: built securityName to securityModel map, version %s: %s' % (self.__paramsBranchId, self.__nameToModelMap))
+            debug.logger & debug.flagSM and debug.logger(
+                '_com2sec: built securityName to securityModel map, version %s: %s' % (
+                    self.__paramsBranchId, self.__nameToModelMap))
 
-        snmpCommunityName, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-COMMUNITY-MIB', 'snmpCommunityName')
+        snmpCommunityName, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-COMMUNITY-MIB',
+                                                                                                   'snmpCommunityName')
         if self.__communityBranchId != snmpCommunityName.branchVersionId:
             (snmpCommunitySecurityName, snmpCommunityContextEngineId,
              snmpCommunityContextName,
              snmpCommunityTransportTag) = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
-                 'SNMP-COMMUNITY-MIB', 'snmpCommunitySecurityName',
-                 'snmpCommunityContextEngineID', 'snmpCommunityContextName',
-                 'snmpCommunityTransportTag'
-             )
+                'SNMP-COMMUNITY-MIB', 'snmpCommunitySecurityName',
+                'snmpCommunityContextEngineID', 'snmpCommunityContextName',
+                'snmpCommunityTransportTag'
+            )
 
             self.__communityToTagMap = {}
             self.__tagAndCommunityToSecurityMap = {}
@@ -205,7 +222,8 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
 
                 securityName = snmpCommunitySecurityName.getNode(snmpCommunitySecurityName.name + instId).syntax
 
-                contextEngineId = snmpCommunityContextEngineId.getNode(snmpCommunityContextEngineId.name + instId).syntax
+                contextEngineId = snmpCommunityContextEngineId.getNode(
+                    snmpCommunityContextEngineId.name + instId).syntax
 
                 contextName = snmpCommunityContextName.getNode(snmpCommunityContextName.name + instId).syntax
 
@@ -227,13 +245,18 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
 
             self.__communityBranchId = snmpCommunityName.branchVersionId
 
-            debug.logger & debug.flagSM and debug.logger('_com2sec: built communityName to tag map (securityModel %s), version %s: %s' % (self.securityModelID, self.__communityBranchId, self.__communityToTagMap))
+            debug.logger & debug.flagSM and debug.logger(
+                '_com2sec: built communityName to tag map (securityModel %s), version %s: %s' % (
+                    self.securityModelID, self.__communityBranchId, self.__communityToTagMap))
 
-            debug.logger & debug.flagSM and debug.logger('_com2sec: built tag & community to securityName map (securityModel %s), version %s: %s' % (self.securityModelID, self.__communityBranchId, self.__tagAndCommunityToSecurityMap))
+            debug.logger & debug.flagSM and debug.logger(
+                '_com2sec: built tag & community to securityName map (securityModel %s), version %s: %s' % (
+                    self.securityModelID, self.__communityBranchId, self.__tagAndCommunityToSecurityMap))
 
         if communityName in self.__communityToTagMap:
             if transportInformation in self.__transportToTagMap:
-                tags = self.__transportToTagMap[transportInformation].intersection(self.__communityToTagMap[communityName])
+                tags = self.__transportToTagMap[transportInformation].intersection(
+                    self.__communityToTagMap[communityName])
             elif self.__emptyTag in self.__communityToTagMap[communityName]:
                 tags = [self.__emptyTag]
             else:
@@ -247,9 +270,14 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
             # 5.2.1 (row selection in snmpCommunityTable)
             # Picks first match but favors entries already in targets table
             if candidateSecurityNames:
-                candidateSecurityNames.sort(key=lambda x, m=self.__nameToModelMap, v=self.securityModelID: (not int(x[0] in m and v in m[x[0]]), str(x[0])))
+                candidateSecurityNames.sort(
+                    key=lambda x, m=self.__nameToModelMap, v=self.securityModelID: (
+                        not int(x[0] in m and v in m[x[0]]), str(x[0]))
+                )
                 chosenSecurityName = candidateSecurityNames[0]  # min()
-                debug.logger & debug.flagSM and debug.logger('_com2sec: securityName candidates for communityName \'%s\' are %s; choosing securityName \'%s\'' % (communityName, candidateSecurityNames, chosenSecurityName[0]))
+                debug.logger & debug.flagSM and debug.logger(
+                    '_com2sec: securityName candidates for communityName \'%s\' are %s; choosing securityName \'%s\'' % (
+                        communityName, candidateSecurityNames, chosenSecurityName[0]))
                 return chosenSecurityName
 
         raise error.StatusInformation(errorIndication=errind.unknownCommunityName)
@@ -265,7 +293,9 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
         communityName = self._sec2com(snmpEngine, securityName,
                                       contextEngineId, contextName)
 
-        debug.logger & debug.flagSM and debug.logger('generateRequestMsg: using community %r for securityModel %r, securityName %r, contextEngineId %r contextName %r' % (communityName, securityModel, securityName, contextEngineId, contextName))
+        debug.logger & debug.flagSM and debug.logger(
+            'generateRequestMsg: using community %r for securityModel %r, securityName %r, contextEngineId %r contextName %r' % (
+                communityName, securityModel, securityName, contextEngineId, contextName))
 
         securityParameters = communityName
 
@@ -281,7 +311,8 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
             return securityParameters, encoder.encode(msg)
 
         except PyAsn1Error:
-            debug.logger & debug.flagMP and debug.logger('generateRequestMsg: serialization failure: %s' % sys.exc_info()[1])
+            debug.logger & debug.flagMP and debug.logger(
+                'generateRequestMsg: serialization failure: %s' % sys.exc_info()[1])
             raise error.StatusInformation(errorIndication=errind.serializationError)
 
     def generateResponseMsg(self, snmpEngine, messageProcessingModel,
@@ -294,7 +325,9 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
         cachedSecurityData = self._cache.pop(securityStateReference)
         communityName = cachedSecurityData['communityName']
 
-        debug.logger & debug.flagSM and debug.logger('generateResponseMsg: recovered community %r by securityStateReference %s' % (communityName, securityStateReference))
+        debug.logger & debug.flagSM and debug.logger(
+            'generateResponseMsg: recovered community %r by securityStateReference %s' % (
+                communityName, securityStateReference))
 
         msg.setComponentByPosition(1, communityName)
         msg.setComponentByPosition(2)
@@ -308,7 +341,8 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
             return communityName, encoder.encode(msg)
 
         except PyAsn1Error:
-            debug.logger & debug.flagMP and debug.logger('generateResponseMsg: serialization failure: %s' % sys.exc_info()[1])
+            debug.logger & debug.flagMP and debug.logger(
+                'generateResponseMsg: serialization failure: %s' % sys.exc_info()[1])
             raise error.StatusInformation(errorIndication=errind.serializationError)
 
     def processIncomingMsg(self, snmpEngine, messageProcessingModel,
@@ -334,11 +368,13 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
             )
 
         except error.StatusInformation:
-            snmpInBadCommunityNames, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMPv2-MIB', 'snmpInBadCommunityNames')
+            snmpInBadCommunityNames, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
+                '__SNMPv2-MIB', 'snmpInBadCommunityNames')
             snmpInBadCommunityNames.syntax += 1
             raise error.StatusInformation(errorIndication=errind.unknownCommunityName)
 
-        snmpEngineID, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')
+        snmpEngineID, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB',
+                                                                                              'snmpEngineID')
 
         securityEngineID = snmpEngineID.syntax
 
@@ -355,7 +391,9 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
             snmpEngine, 'rfc2576.processIncomingMsg'
         )
 
-        debug.logger & debug.flagSM and debug.logger('processIncomingMsg: looked up securityName %r securityModel %r contextEngineId %r contextName %r by communityName %r AND transportInformation %r' % (securityName, self.securityModelID, contextEngineId, contextName, communityName, transportInformation))
+        debug.logger & debug.flagSM and debug.logger(
+            'processIncomingMsg: looked up securityName %r securityModel %r contextEngineId %r contextName %r by communityName %r AND transportInformation %r' % (
+                securityName, self.securityModelID, contextEngineId, contextName, communityName, transportInformation))
 
         stateReference = self._cache.push(communityName=communityName)
 
@@ -364,11 +402,14 @@ class SnmpV1SecurityModel(base.AbstractSecurityModel):
         maxSizeResponseScopedPDU = maxMessageSize - 128
         securityStateReference = stateReference
 
-        debug.logger & debug.flagSM and debug.logger('processIncomingMsg: generated maxSizeResponseScopedPDU %s securityStateReference %s' % (maxSizeResponseScopedPDU, securityStateReference))
+        debug.logger & debug.flagSM and debug.logger(
+            'processIncomingMsg: generated maxSizeResponseScopedPDU %s securityStateReference %s' % (
+                maxSizeResponseScopedPDU, securityStateReference))
 
         return (securityEngineID, securityName, scopedPDU,
                 maxSizeResponseScopedPDU, securityStateReference)
 
+
 class SnmpV2cSecurityModel(SnmpV1SecurityModel):
     securityModelID = 2
 
diff --git a/pysnmp/proto/secmod/rfc3414/__init__.py b/pysnmp/proto/secmod/rfc3414/__init__.py
index 59df8fb2..75d3de1c 100644
--- a/pysnmp/proto/secmod/rfc3414/__init__.py
+++ b/pysnmp/proto/secmod/rfc3414/__init__.py
@@ -1,3 +1,9 @@
+#
+# This file is part of pysnmp software.
+#
+# Copyright (c) 2005-2016, Ilya Etingof <ilya@glas.net>
+# License: http://pysnmp.sf.net/license.html
+#
 from pysnmp.proto.secmod.rfc3414 import service
 
 SnmpUSMSecurityModel = service.SnmpUSMSecurityModel
diff --git a/pysnmp/proto/secmod/rfc3414/auth/hmacmd5.py b/pysnmp/proto/secmod/rfc3414/auth/hmacmd5.py
index edd6d916..38f34483 100644
--- a/pysnmp/proto/secmod/rfc3414/auth/hmacmd5.py
+++ b/pysnmp/proto/secmod/rfc3414/auth/hmacmd5.py
@@ -8,21 +8,23 @@ try:
     from hashlib import md5
 except ImportError:
     import md5
+
     md5 = md5.new
 from pyasn1.type import univ
 from pysnmp.proto.secmod.rfc3414.auth import base
 from pysnmp.proto.secmod.rfc3414 import localkey
 from pysnmp.proto import errind, error
 
-_twelveZeros = univ.OctetString((0,)*12).asOctets()
-_fortyEightZeros = (0,)*48
+_twelveZeros = univ.OctetString((0,) * 12).asOctets()
+_fortyEightZeros = (0,) * 48
+
 
 # rfc3414: 6.2.4
 
 class HmacMd5(base.AbstractAuthenticationService):
     serviceID = (1, 3, 6, 1, 6, 3, 10, 1, 1, 2)  # usmHMACMD5AuthProtocol
-    __ipad = [0x36]*64
-    __opad = [0x5C]*64
+    __ipad = [0x36] * 64
+    __opad = [0x5C] * 64
 
     def hashPassphrase(self, authKey):
         return localkey.hashPassphraseMD5(authKey)
@@ -40,7 +42,7 @@ class HmacMd5(base.AbstractAuthenticationService):
         if l == -1:
             raise error.ProtocolError('Cant locate digest placeholder')
         wholeHead = wholeMsg[:l]
-        wholeTail = wholeMsg[l+12:]
+        wholeTail = wholeMsg[l + 12:]
 
         # 6.3.1.1
 
@@ -51,21 +53,23 @@ class HmacMd5(base.AbstractAuthenticationService):
 
         # 6.3.1.2c
         k1 = univ.OctetString(
-            map(lambda x, y: x^y, extendedAuthKey, self.__ipad)
+            map(lambda x, y: x ^ y, extendedAuthKey, self.__ipad)
         )
 
         # 6.3.1.2d --> noop
 
         # 6.3.1.2e
         k2 = univ.OctetString(
-            map(lambda x, y: x^y, extendedAuthKey, self.__opad)
+            map(lambda x, y: x ^ y, extendedAuthKey, self.__opad)
         )
 
         # 6.3.1.3
-        d1 = md5(k1.asOctets()+wholeMsg).digest()
+        # noinspection PyDeprecation,PyCallingNonCallable
+        d1 = md5(k1.asOctets() + wholeMsg).digest()
 
         # 6.3.1.4
-        d2 = md5(k2.asOctets()+d1).digest()
+        # noinspection PyDeprecation,PyCallingNonCallable
+        d2 = md5(k2.asOctets() + d1).digest()
         mac = d2[:12]
 
         # 6.3.1.5 & 6
@@ -84,7 +88,7 @@ class HmacMd5(base.AbstractAuthenticationService):
         if l == -1:
             raise error.ProtocolError('Cant locate digest in wholeMsg')
         wholeHead = wholeMsg[:l]
-        wholeTail = wholeMsg[l+12:]
+        wholeTail = wholeMsg[l + 12:]
         authenticatedWholeMsg = wholeHead + _twelveZeros + wholeTail
 
         # 6.3.2.4a
@@ -94,21 +98,23 @@ class HmacMd5(base.AbstractAuthenticationService):
 
         # 6.3.2.4c
         k1 = univ.OctetString(
-            map(lambda x, y: x^y, extendedAuthKey, self.__ipad)
+            map(lambda x, y: x ^ y, extendedAuthKey, self.__ipad)
         )
 
         # 6.3.2.4d --> noop
 
         # 6.3.2.4e
         k2 = univ.OctetString(
-            map(lambda x, y: x^y, extendedAuthKey, self.__opad)
+            map(lambda x, y: x ^ y, extendedAuthKey, self.__opad)
         )
 
         # 6.3.2.5a
-        d1 = md5(k1.asOctets()+authenticatedWholeMsg).digest()
+        # noinspection PyDeprecation,PyCallingNonCallable
+        d1 = md5(k1.asOctets() + authenticatedWholeMsg).digest()
 
         # 6.3.2.5b
-        d2 = md5(k2.asOctets()+d1).digest()
+        # noinspection PyDeprecation,PyCallingNonCallable
+        d2 = md5(k2.asOctets() + d1).digest()
 
         # 6.3.2.5c
         mac = d2[:12]
diff --git a/pysnmp/proto/secmod/rfc3414/auth/hmacsha.py b/pysnmp/proto/secmod/rfc3414/auth/hmacsha.py
index 95c7af8d..ef365f1f 100644
--- a/pysnmp/proto/secmod/rfc3414/auth/hmacsha.py
+++ b/pysnmp/proto/secmod/rfc3414/auth/hmacsha.py
@@ -8,21 +8,23 @@ try:
     from hashlib import sha1
 except ImportError:
     import sha
+
     sha1 = sha.new
 from pyasn1.type import univ
 from pysnmp.proto.secmod.rfc3414.auth import base
 from pysnmp.proto.secmod.rfc3414 import localkey
 from pysnmp.proto import errind, error
 
-_twelveZeros = univ.OctetString((0,)*12).asOctets()
-_fortyFourZeros = (0,)*44
+_twelveZeros = univ.OctetString((0,) * 12).asOctets()
+_fortyFourZeros = (0,) * 44
+
 
 # 7.2.4
 
 class HmacSha(base.AbstractAuthenticationService):
     serviceID = (1, 3, 6, 1, 6, 3, 10, 1, 1, 3)  # usmHMACSHAAuthProtocol
-    __ipad = [0x36]*64
-    __opad = [0x5C]*64
+    __ipad = [0x36] * 64
+    __opad = [0x5C] * 64
 
     def hashPassphrase(self, authKey):
         return localkey.hashPassphraseSHA(authKey)
@@ -41,7 +43,7 @@ class HmacSha(base.AbstractAuthenticationService):
         if l == -1:
             raise error.ProtocolError('Cant locate digest placeholder')
         wholeHead = wholeMsg[:l]
-        wholeTail = wholeMsg[l+12:]
+        wholeTail = wholeMsg[l + 12:]
 
         # 7.3.1.2a
         extendedAuthKey = authKey.asNumbers() + _fortyFourZeros
@@ -50,21 +52,21 @@ class HmacSha(base.AbstractAuthenticationService):
 
         # 7.3.1.2c
         k1 = univ.OctetString(
-            map(lambda x, y: x^y, extendedAuthKey, self.__ipad)
+            map(lambda x, y: x ^ y, extendedAuthKey, self.__ipad)
         )
 
         # 7.3.1.2d -- noop
 
         # 7.3.1.2e
         k2 = univ.OctetString(
-            map(lambda x, y: x^y, extendedAuthKey, self.__opad)
+            map(lambda x, y: x ^ y, extendedAuthKey, self.__opad)
         )
 
         # 7.3.1.3
-        d1 = sha1(k1.asOctets()+wholeMsg).digest()
+        d1 = sha1(k1.asOctets() + wholeMsg).digest()
 
         # 7.3.1.4
-        d2 = sha1(k2.asOctets()+d1).digest()
+        d2 = sha1(k2.asOctets() + d1).digest()
         mac = d2[:12]
 
         # 7.3.1.5 & 6
@@ -83,7 +85,7 @@ class HmacSha(base.AbstractAuthenticationService):
         if l == -1:
             raise error.ProtocolError('Cant locate digest in wholeMsg')
         wholeHead = wholeMsg[:l]
-        wholeTail = wholeMsg[l+12:]
+        wholeTail = wholeMsg[l + 12:]
         authenticatedWholeMsg = wholeHead + _twelveZeros + wholeTail
 
         # 7.3.2.4a
@@ -93,21 +95,21 @@ class HmacSha(base.AbstractAuthenticationService):
 
         # 7.3.2.4c
         k1 = univ.OctetString(
-            map(lambda x, y: x^y, extendedAuthKey, self.__ipad)
+            map(lambda x, y: x ^ y, extendedAuthKey, self.__ipad)
         )
 
         # 7.3.2.4d --> noop
 
         # 7.3.2.4e
         k2 = univ.OctetString(
-            map(lambda x, y: x^y, extendedAuthKey, self.__opad)
+            map(lambda x, y: x ^ y, extendedAuthKey, self.__opad)
         )
 
         # 7.3.2.5a
-        d1 = sha1(k1.asOctets()+authenticatedWholeMsg).digest()
+        d1 = sha1(k1.asOctets() + authenticatedWholeMsg).digest()
 
         # 7.3.2.5b
-        d2 = sha1(k2.asOctets()+d1).digest()
+        d2 = sha1(k2.asOctets() + d1).digest()
 
         # 7.3.2.5c
         mac = d2[:12]
diff --git a/pysnmp/proto/secmod/rfc3414/auth/noauth.py b/pysnmp/proto/secmod/rfc3414/auth/noauth.py
index 721a2456..0a89391b 100644
--- a/pysnmp/proto/secmod/rfc3414/auth/noauth.py
+++ b/pysnmp/proto/secmod/rfc3414/auth/noauth.py
@@ -7,6 +7,7 @@
 from pysnmp.proto.secmod.rfc3414.auth import base
 from pysnmp.proto import errind, error
 
+
 class NoAuth(base.AbstractAuthenticationService):
     serviceID = (1, 3, 6, 1, 6, 3, 10, 1, 1, 1)  # usmNoAuthProtocol
 
diff --git a/pysnmp/proto/secmod/rfc3414/localkey.py b/pysnmp/proto/secmod/rfc3414/localkey.py
index bb05d47c..e9b642c3 100644
--- a/pysnmp/proto/secmod/rfc3414/localkey.py
+++ b/pysnmp/proto/secmod/rfc3414/localkey.py
@@ -7,16 +7,21 @@
 try:
     from hashlib import md5, sha1
 except ImportError:
-    import md5, sha
+    import md5
+    import sha
+
     md5 = md5.new
     sha1 = sha.new
 from pyasn1.type import univ
 
+
 # RFC3414: A.2.1
 def hashPassphraseMD5(passphrase):
     passphrase = univ.OctetString(passphrase).asOctets()
+    # noinspection PyDeprecation,PyCallingNonCallable
     md = md5()
-    ringBuffer = passphrase * (passphrase and (64//len(passphrase)+1) or 1)
+    ringBuffer = passphrase * (passphrase and (64 // len(passphrase) + 1) or 1)
+    # noinspection PyTypeChecker
     ringBufferLen = len(ringBuffer)
     count = 0
     mark = 0
@@ -27,24 +32,29 @@ def hashPassphraseMD5(passphrase):
             mark = e
         else:
             md.update(
-                ringBuffer[mark:ringBufferLen] + ringBuffer[0:e-ringBufferLen]
+                ringBuffer[mark:ringBufferLen] + ringBuffer[0:e - ringBufferLen]
             )
-            mark = e-ringBufferLen
+            mark = e - ringBufferLen
         count += 1
     return md.digest()
 
+
 def localizeKeyMD5(passKey, snmpEngineId):
     passKey = univ.OctetString(passKey).asOctets()
-    return md5(passKey + snmpEngineId.asOctets()+ passKey).digest()
+    # noinspection PyDeprecation,PyCallingNonCallable
+    return md5(passKey + snmpEngineId.asOctets() + passKey).digest()
+
 
 def passwordToKeyMD5(passphrase, snmpEngineId):
     return localizeKeyMD5(hashPassphraseMD5(passphrase), snmpEngineId)
 
+
 # RFC3414: A.2.2
 def hashPassphraseSHA(passphrase):
     passphrase = univ.OctetString(passphrase).asOctets()
     md = sha1()
-    ringBuffer = passphrase * (64//len(passphrase)+1)
+    ringBuffer = passphrase * (64 // len(passphrase) + 1)
+    # noinspection PyTypeChecker
     ringBufferLen = len(ringBuffer)
     count = 0
     mark = 0
@@ -55,15 +65,17 @@ def hashPassphraseSHA(passphrase):
             mark = e
         else:
             md.update(
-                ringBuffer[mark:ringBufferLen] + ringBuffer[0:e-ringBufferLen]
+                ringBuffer[mark:ringBufferLen] + ringBuffer[0:e - ringBufferLen]
             )
-            mark = e-ringBufferLen
+            mark = e - ringBufferLen
         count += 1
     return md.digest()
 
+
 def localizeKeySHA(passKey, snmpEngineId):
     passKey = univ.OctetString(passKey).asOctets()
-    return sha1(passKey + snmpEngineId.asOctets()+ passKey).digest()
+    return sha1(passKey + snmpEngineId.asOctets() + passKey).digest()
+
 
 def passwordToKeySHA(passphrase, snmpEngineId):
     return localizeKeySHA(hashPassphraseSHA(passphrase), snmpEngineId)
diff --git a/pysnmp/proto/secmod/rfc3414/priv/base.py b/pysnmp/proto/secmod/rfc3414/priv/base.py
index a9685d6d..224e19aa 100644
--- a/pysnmp/proto/secmod/rfc3414/priv/base.py
+++ b/pysnmp/proto/secmod/rfc3414/priv/base.py
@@ -6,6 +6,7 @@
 #
 from pysnmp.proto import error
 
+
 class AbstractEncryptionService:
     serviceID = None
 
diff --git a/pysnmp/proto/secmod/rfc3414/priv/des.py b/pysnmp/proto/secmod/rfc3414/priv/des.py
index e011fd66..16b882bd 100644
--- a/pysnmp/proto/secmod/rfc3414/priv/des.py
+++ b/pysnmp/proto/secmod/rfc3414/priv/des.py
@@ -19,12 +19,13 @@ except ImportError:
 
 random.seed()
 
+
 # 8.2.4
 
 class Des(base.AbstractEncryptionService):
-    serviceID = (1, 3, 6, 1, 6, 3, 10, 1, 2, 2) # usmDESPrivProtocol
+    serviceID = (1, 3, 6, 1, 6, 3, 10, 1, 2, 2)  # usmDESPrivProtocol
     if version_info < (2, 3):
-        _localInt = int(random.random()*0xffffffff)
+        _localInt = int(random.random() * 0xffffffff)
     else:
         _localInt = random.randrange(0, 0xffffffff)
 
@@ -47,7 +48,7 @@ class Des(base.AbstractEncryptionService):
             raise error.ProtocolError(
                 'Unknown auth protocol %s' % (authProtocol,)
             )
-        return localPrivKey[:32] # key+IV
+        return localPrivKey[:32]  # key+IV
 
     # 8.1.1.1
     def __getEncryptionKey(self, privKey, snmpEngineBoots):
@@ -56,14 +57,14 @@ class Des(base.AbstractEncryptionService):
 
         securityEngineBoots = int(snmpEngineBoots)
 
-        salt = [securityEngineBoots>>24&0xff,
-                securityEngineBoots>>16&0xff,
-                securityEngineBoots>>8&0xff,
-                securityEngineBoots&0xff,
-                self._localInt>>24&0xff,
-                self._localInt>>16&0xff,
-                self._localInt>>8&0xff,
-                self._localInt&0xff]
+        salt = [securityEngineBoots >> 24 & 0xff,
+                securityEngineBoots >> 16 & 0xff,
+                securityEngineBoots >> 8 & 0xff,
+                securityEngineBoots & 0xff,
+                self._localInt >> 24 & 0xff,
+                self._localInt >> 16 & 0xff,
+                self._localInt >> 8 & 0xff,
+                self._localInt & 0xff]
         if self._localInt == 0xffffffff:
             self._localInt = 0
         else:
@@ -71,11 +72,12 @@ class Des(base.AbstractEncryptionService):
 
         return (desKey.asOctets(),
                 univ.OctetString(salt).asOctets(),
-                univ.OctetString(map(lambda x, y: x^y, salt, preIV.asNumbers())).asOctets())
+                univ.OctetString(map(lambda x, y: x ^ y, salt, preIV.asNumbers())).asOctets())
 
-    def __getDecryptionKey(self, privKey, salt):
+    @staticmethod
+    def __getDecryptionKey(privKey, salt):
         return (privKey[:8].asOctets(),
-                univ.OctetString(map(lambda x, y: x^y, salt.asNumbers(), privKey[8:16].asNumbers())).asOctets())
+                univ.OctetString(map(lambda x, y: x ^ y, salt.asNumbers(), privKey[8:16].asNumbers())).asOctets())
 
     # 8.2.4.1
     def encryptData(self, encryptKey, privParameters, dataToEncrypt):
diff --git a/pysnmp/proto/secmod/rfc3414/priv/nopriv.py b/pysnmp/proto/secmod/rfc3414/priv/nopriv.py
index a1491aef..1d4499b3 100644
--- a/pysnmp/proto/secmod/rfc3414/priv/nopriv.py
+++ b/pysnmp/proto/secmod/rfc3414/priv/nopriv.py
@@ -7,8 +7,10 @@
 from pysnmp.proto.secmod.rfc3414.priv import base
 from pysnmp.proto import errind, error
 
+
 class NoPriv(base.AbstractEncryptionService):
-    serviceID = (1, 3, 6, 1, 6, 3, 10, 1, 2, 1) # usmNoPrivProtocol
+    serviceID = (1, 3, 6, 1, 6, 3, 10, 1, 2, 1)  # usmNoPrivProtocol
+
     def hashPassphrase(self, authProtocol, privKey):
         return
 
diff --git a/pysnmp/proto/secmod/rfc3414/service.py b/pysnmp/proto/secmod/rfc3414/service.py
index 9976a06a..7bcf551c 100644
--- a/pysnmp/proto/secmod/rfc3414/service.py
+++ b/pysnmp/proto/secmod/rfc3414/service.py
@@ -4,7 +4,8 @@
 # Copyright (c) 2005-2016, Ilya Etingof <ilya@glas.net>
 # License: http://pysnmp.sf.net/license.html
 #
-import time, sys
+import time
+import sys
 from pysnmp.proto.secmod.base import AbstractSecurityModel
 from pysnmp.proto.secmod.rfc3414.auth import hmacmd5, hmacsha, noauth
 from pysnmp.proto.secmod.rfc3414.priv import des, nopriv
@@ -18,18 +19,23 @@ from pyasn1.codec.ber import encoder, decoder, eoo
 from pyasn1.error import PyAsn1Error
 from pyasn1.compat.octets import null
 
+
 # USM security params
 
 class UsmSecurityParameters(rfc1155.TypeCoercionHackMixIn, univ.Sequence):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('msgAuthoritativeEngineId', univ.OctetString()),
-        namedtype.NamedType('msgAuthoritativeEngineBoots', univ.Integer().subtype(subtypeSpec=constraint.ValueRangeConstraint(0, 2147483647))),
-        namedtype.NamedType('msgAuthoritativeEngineTime', univ.Integer().subtype(subtypeSpec=constraint.ValueRangeConstraint(0, 2147483647))),
-        namedtype.NamedType('msgUserName', univ.OctetString().subtype(subtypeSpec=constraint.ValueSizeConstraint(0, 32))),
+        namedtype.NamedType('msgAuthoritativeEngineBoots',
+                            univ.Integer().subtype(subtypeSpec=constraint.ValueRangeConstraint(0, 2147483647))),
+        namedtype.NamedType('msgAuthoritativeEngineTime',
+                            univ.Integer().subtype(subtypeSpec=constraint.ValueRangeConstraint(0, 2147483647))),
+        namedtype.NamedType('msgUserName',
+                            univ.OctetString().subtype(subtypeSpec=constraint.ValueSizeConstraint(0, 32))),
         namedtype.NamedType('msgAuthenticationParameters', univ.OctetString()),
         namedtype.NamedType('msgPrivacyParameters', univ.OctetString())
     )
 
+
 class SnmpUSMSecurityModel(AbstractSecurityModel):
     securityModelID = 3
     authServices = {hmacmd5.HmacMd5.serviceID: hmacmd5.HmacMd5(),
@@ -41,6 +47,7 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                     aes192.Aes192.serviceID: aes192.Aes192(),
                     aes256.Aes256.serviceID: aes256.Aes256(),
                     nopriv.NoPriv.serviceID: nopriv.NoPriv()}
+
     def __init__(self):
         AbstractSecurityModel.__init__(self)
         self.__securityParametersSpec = UsmSecurityParameters()
@@ -50,9 +57,12 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
         self.__paramsBranchId = -1
 
     def __sec2usr(self, snmpEngine, securityName, securityEngineID=None):
-        usmUserEngineID, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-USER-BASED-SM-MIB', 'usmUserEngineID')
+        mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
+        usmUserEngineID, = mibBuilder.importSymbols('SNMP-USER-BASED-SM-MIB',
+                                                    'usmUserEngineID')
         if self.__paramsBranchId != usmUserEngineID.branchVersionId:
-            usmUserName, usmUserSecurityName = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-USER-BASED-SM-MIB', 'usmUserName', 'usmUserSecurityName')
+            usmUserName, usmUserSecurityName = mibBuilder.importSymbols(
+                'SNMP-USER-BASED-SM-MIB', 'usmUserName', 'usmUserSecurityName')
 
             self.__securityToUserMap = {}
 
@@ -64,7 +74,9 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
 
                 except NoSuchInstanceError:
                     self.__paramsBranchId = usmUserEngineID.branchVersionId
-                    debug.logger & debug.flagSM and debug.logger('_sec2usr: built snmpEngineId + securityName to userName map, version %s: %r' % (self.__paramsBranchId, self.__securityToUserMap))
+                    debug.logger & debug.flagSM and debug.logger(
+                        '_sec2usr: built snmpEngineId + securityName to userName map, version %s: %r' % (
+                            self.__paramsBranchId, self.__securityToUserMap))
                     break
 
                 instId = nextMibNode.name[len(usmUserSecurityName.name):]
@@ -80,20 +92,24 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                     self.__securityToUserMap[k] = __userName
 
         if securityEngineID is None:
-            snmpEngineID, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')
+            snmpEngineID, = mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')
             securityEngineID = snmpEngineID.syntax
 
         try:
             userName = self.__securityToUserMap[(securityEngineID, securityName)]
         except KeyError:
-            debug.logger & debug.flagSM and debug.logger('_sec2usr: no entry exists for snmpEngineId %r, securityName %r' % (securityEngineID, securityName))
+            debug.logger & debug.flagSM and debug.logger(
+                '_sec2usr: no entry exists for snmpEngineId %r, securityName %r' % (securityEngineID, securityName))
             raise NoSuchInstanceError()  # emulate MIB lookup
 
-        debug.logger & debug.flagSM and debug.logger('_sec2usr: using userName %r for snmpEngineId %r, securityName %r' % (userName, securityEngineID, securityName))
+        debug.logger & debug.flagSM and debug.logger(
+            '_sec2usr: using userName %r for snmpEngineId %r, securityName %r' % (
+                userName, securityEngineID, securityName))
 
         return userName
 
-    def __getUserInfo(self, mibInstrumController, securityEngineID, userName):
+    @staticmethod
+    def __getUserInfo(mibInstrumController, securityEngineID, userName):
         usmUserEntry, = mibInstrumController.mibBuilder.importSymbols(
             'SNMP-USER-BASED-SM-MIB', 'usmUserEntry'
         )
@@ -198,7 +214,9 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                                        securityModel, securityEngineID,
                                        securityName, securityLevel,
                                        scopedPDU, securityStateReference):
-        snmpEngineID = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')[0].syntax
+        mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
+        snmpEngineID = mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')[0].syntax
+
         # 3.1.1
         if securityStateReference is not None:
             # 3.1.1a
@@ -232,14 +250,14 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                 (usmUserName, usmUserSecurityName, usmUserAuthProtocol,
                  usmUserAuthKeyLocalized, usmUserPrivProtocol,
                  usmUserPrivKeyLocalized) = self.__getUserInfo(
-                     snmpEngine.msgAndPduDsp.mibInstrumController,
-                     securityEngineID,
-                     self.__sec2usr(snmpEngine, securityName, securityEngineID)
-                 )
+                    snmpEngine.msgAndPduDsp.mibInstrumController,
+                    securityEngineID,
+                    self.__sec2usr(snmpEngine, securityName, securityEngineID)
+                )
                 debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: read user info')
 
             except NoSuchInstanceError:
-                pysnmpUsmDiscovery, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__PYSNMP-USM-MIB', 'pysnmpUsmDiscovery')
+                pysnmpUsmDiscovery, = mibBuilder.importSymbols('__PYSNMP-USM-MIB', 'pysnmpUsmDiscovery')
                 reportUnknownName = not pysnmpUsmDiscovery.syntax
                 if not reportUnknownName:
                     try:
@@ -247,10 +265,10 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                          usmUserAuthProtocol, usmUserAuthKeyLocalized,
                          usmUserPrivProtocol,
                          usmUserPrivKeyLocalized) = self.__cloneUserInfo(
-                             snmpEngine.msgAndPduDsp.mibInstrumController,
-                             securityEngineID,
-                             self.__sec2usr(snmpEngine, securityName)
-                         )
+                            snmpEngine.msgAndPduDsp.mibInstrumController,
+                            securityEngineID,
+                            self.__sec2usr(snmpEngine, securityName)
+                        )
 
                     except NoSuchInstanceError:
                         reportUnknownName = True
@@ -263,8 +281,9 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                 debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: clone user info')
 
             except PyAsn1Error:
-                debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: %s' % (sys.exc_info()[1],))
-                snmpInGenErrs, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMPv2-MIB', 'snmpInGenErrs')
+                debug.logger & debug.flagSM and debug.logger(
+                    '__generateRequestOrResponseMsg: %s' % (sys.exc_info()[1],))
+                snmpInGenErrs, = mibBuilder.importSymbols('__SNMPv2-MIB', 'snmpInGenErrs')
                 snmpInGenErrs.syntax += 1
                 raise error.StatusInformation(
                     errorIndication=errind.invalidMsg
@@ -277,14 +296,17 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
             usmUserAuthKeyLocalized = usmUserPrivKeyLocalized = None
             debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: use empty USM data')
 
-        debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: local usmUserName %r usmUserSecurityName %r usmUserAuthProtocol %s usmUserPrivProtocol %s securityEngineID %r securityName %r' % (usmUserName, usmUserSecurityName, usmUserAuthProtocol, usmUserPrivProtocol, securityEngineID, securityName))
+        # noinspection PyUnboundLocalVariable
+        debug.logger & debug.flagSM and debug.logger(
+            '__generateRequestOrResponseMsg: local usmUserName %r usmUserSecurityName %r usmUserAuthProtocol %s usmUserPrivProtocol %s securityEngineID %r securityName %r' % (
+                usmUserName, usmUserSecurityName, usmUserAuthProtocol, usmUserPrivProtocol, securityEngineID, securityName))
 
         msg = globalData
 
         # 3.1.2
         if securityLevel == 3:
             if usmUserAuthProtocol == noauth.NoAuth.serviceID or \
-               usmUserPrivProtocol == nopriv.NoPriv.serviceID:
+                    usmUserPrivProtocol == nopriv.NoPriv.serviceID:
                 raise error.StatusInformation(
                     errorIndication=errind.unsupportedSecurityLevel
                 )
@@ -308,24 +330,30 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
             if securityEngineID in self.__timeline:
                 (snmpEngineBoots, snmpEngineTime, latestReceivedEngineTime,
                  latestUpdateTimestamp) = self.__timeline[securityEngineID]
-                debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: read snmpEngineBoots, snmpEngineTime from timeline')
+                debug.logger & debug.flagSM and debug.logger(
+                    '__generateRequestOrResponseMsg: read snmpEngineBoots, snmpEngineTime from timeline')
             else:
                 # 2.3 XXX is this correct?
                 snmpEngineBoots = snmpEngineTime = 0
-                debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: no timeline for securityEngineID %r' % (securityEngineID,))
+                debug.logger & debug.flagSM and debug.logger(
+                    '__generateRequestOrResponseMsg: no timeline for securityEngineID %r' % (securityEngineID,))
         # 3.1.6.b
         elif securityStateReference is not None:  # XXX Report?
             (snmpEngineBoots,
-             snmpEngineTime) = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineBoots', 'snmpEngineTime')
+             snmpEngineTime) = mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineBoots', 'snmpEngineTime')
             snmpEngineBoots = snmpEngineBoots.syntax
             snmpEngineTime = snmpEngineTime.syntax.clone()
-            debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: read snmpEngineBoots, snmpEngineTime from LCD')
+            debug.logger & debug.flagSM and debug.logger(
+                '__generateRequestOrResponseMsg: read snmpEngineBoots, snmpEngineTime from LCD')
         # 3.1.6.c
         else:
             snmpEngineBoots = snmpEngineTime = 0
-            debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: assuming zero snmpEngineBoots, snmpEngineTime')
+            debug.logger & debug.flagSM and debug.logger(
+                '__generateRequestOrResponseMsg: assuming zero snmpEngineBoots, snmpEngineTime')
 
-        debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: use snmpEngineBoots %s snmpEngineTime %s for securityEngineID %r' % (snmpEngineBoots, snmpEngineTime, securityEngineID))
+        debug.logger & debug.flagSM and debug.logger(
+            '__generateRequestOrResponseMsg: use snmpEngineBoots %s snmpEngineTime %s for securityEngineID %r' % (
+                snmpEngineBoots, snmpEngineTime, securityEngineID))
 
         # 3.1.4a
         if securityLevel == 3:
@@ -336,24 +364,28 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                     errorIndication=errind.encryptionError
                 )
 
-            debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: scopedPDU %s' % scopedPDU.prettyPrint())
+            debug.logger & debug.flagSM and debug.logger(
+                '__generateRequestOrResponseMsg: scopedPDU %s' % scopedPDU.prettyPrint())
 
             try:
                 dataToEncrypt = encoder.encode(scopedPDU)
 
             except PyAsn1Error:
-                debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: scopedPDU serialization error: %s' % sys.exc_info()[1])
+                debug.logger & debug.flagSM and debug.logger(
+                    '__generateRequestOrResponseMsg: scopedPDU serialization error: %s' % sys.exc_info()[1])
                 raise error.StatusInformation(
                     errorIndication=errind.serializationError
                 )
 
-            debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: scopedPDU encoded into %s' % debug.hexdump(dataToEncrypt))
+            debug.logger & debug.flagSM and debug.logger(
+                '__generateRequestOrResponseMsg: scopedPDU encoded into %s' % debug.hexdump(dataToEncrypt))
 
+            # noinspection PyUnboundLocalVariable
             (encryptedData,
              privParameters) = privHandler.encryptData(
-                 usmUserPrivKeyLocalized,
-                 (snmpEngineBoots, snmpEngineTime, None), dataToEncrypt
-             )
+                usmUserPrivKeyLocalized,
+                (snmpEngineBoots, snmpEngineTime, None), dataToEncrypt
+            )
 
             securityParameters.setComponentByPosition(
                 5, privParameters, verifyConstraints=False
@@ -362,7 +394,8 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                 1, encryptedData, verifyConstraints=False
             )
 
-            debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: scopedPDU ciphered into %s' % debug.hexdump(encryptedData))
+            debug.logger & debug.flagSM and debug.logger(
+                '__generateRequestOrResponseMsg: scopedPDU ciphered into %s' % debug.hexdump(encryptedData))
 
         # 3.1.4b
         elif securityLevel == 1 or securityLevel == 2:
@@ -400,28 +433,33 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                 4, '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
             )
 
-            debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: %s' % (securityParameters.prettyPrint(),))
+            debug.logger & debug.flagSM and debug.logger(
+                '__generateRequestOrResponseMsg: %s' % (securityParameters.prettyPrint(),))
 
             try:
                 msg.setComponentByPosition(2, encoder.encode(securityParameters), verifyConstraints=False)
 
             except PyAsn1Error:
-                debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: securityParameters serialization error: %s' % sys.exc_info()[1])
+                debug.logger & debug.flagSM and debug.logger(
+                    '__generateRequestOrResponseMsg: securityParameters serialization error: %s' % sys.exc_info()[1])
                 raise error.StatusInformation(
                     errorIndication=errind.serializationError
                 )
 
-            debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: auth outgoing msg: %s' % msg.prettyPrint())
+            debug.logger & debug.flagSM and debug.logger(
+                '__generateRequestOrResponseMsg: auth outgoing msg: %s' % msg.prettyPrint())
 
             try:
                 wholeMsg = encoder.encode(msg)
 
             except PyAsn1Error:
-                debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: msg serialization error: %s' % sys.exc_info()[1])
+                debug.logger & debug.flagSM and debug.logger(
+                    '__generateRequestOrResponseMsg: msg serialization error: %s' % sys.exc_info()[1])
                 raise error.StatusInformation(
                     errorIndication=errind.serializationError
                 )
 
+            # noinspection PyUnboundLocalVariable
             authenticatedWholeMsg = authHandler.authenticateOutgoingMsg(
                 usmUserAuthKeyLocalized, wholeMsg
             )
@@ -432,31 +470,36 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                 4, '', verifyConstraints=False
             )
 
-            debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: %s' % (securityParameters.prettyPrint(),))
+            debug.logger & debug.flagSM and debug.logger(
+                '__generateRequestOrResponseMsg: %s' % (securityParameters.prettyPrint(),))
 
             try:
                 msg.setComponentByPosition(2, encoder.encode(securityParameters), verifyConstraints=False)
 
             except PyAsn1Error:
-                debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: secutiryParameters serialization error: %s' % sys.exc_info()[1])
+                debug.logger & debug.flagSM and debug.logger(
+                    '__generateRequestOrResponseMsg: secutiryParameters serialization error: %s' % sys.exc_info()[1])
                 raise error.StatusInformation(
                     errorIndication=errind.serializationError
                 )
 
             try:
-                debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: plain outgoing msg: %s' % msg.prettyPrint())
+                debug.logger & debug.flagSM and debug.logger(
+                    '__generateRequestOrResponseMsg: plain outgoing msg: %s' % msg.prettyPrint())
                 authenticatedWholeMsg = encoder.encode(msg)
 
             except PyAsn1Error:
-                debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: msg serialization error: %s' % sys.exc_info()[1])
+                debug.logger & debug.flagSM and debug.logger(
+                    '__generateRequestOrResponseMsg: msg serialization error: %s' % sys.exc_info()[1])
                 raise error.StatusInformation(
                     errorIndication=errind.serializationError
                 )
 
-        debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: %s outgoing msg: %s' % (securityLevel > 1 and "authenticated" or "plain", debug.hexdump(authenticatedWholeMsg)))
+        debug.logger & debug.flagSM and debug.logger('__generateRequestOrResponseMsg: %s outgoing msg: %s' % (
+            securityLevel > 1 and "authenticated" or "plain", debug.hexdump(authenticatedWholeMsg)))
 
         # 3.1.9
-        return (msg.getComponentByPosition(2), authenticatedWholeMsg)
+        return msg.getComponentByPosition(2), authenticatedWholeMsg
 
     def generateRequestMsg(self, snmpEngine, messageProcessingModel,
                            globalData, maxMessageSize, securityModel,
@@ -487,12 +530,15 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
     def processIncomingMsg(self, snmpEngine, messageProcessingModel,
                            maxMessageSize, securityParameters,
                            securityModel, securityLevel, wholeMsg, msg):
+        mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
+
         # 3.2.9 -- moved up here to be able to report
         # maxSizeResponseScopedPDU on error
         # (48 - maximum SNMPv3 header length)
         maxSizeResponseScopedPDU = int(maxMessageSize) - len(securityParameters) - 48
 
-        debug.logger & debug.flagSM and debug.logger('processIncomingMsg: securityParameters %s' % debug.hexdump(securityParameters))
+        debug.logger & debug.flagSM and debug.logger(
+            'processIncomingMsg: securityParameters %s' % debug.hexdump(securityParameters))
 
         # 3.2.1
         try:
@@ -502,7 +548,7 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
 
         except PyAsn1Error:
             debug.logger & debug.flagSM and debug.logger('processIncomingMsg: %s' % (sys.exc_info()[1],))
-            snmpInASNParseErrs, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMPv2-MIB', 'snmpInASNParseErrs')
+            snmpInASNParseErrs, = mibBuilder.importSymbols('__SNMPv2-MIB', 'snmpInASNParseErrs')
             snmpInASNParseErrs.syntax += 1
             raise error.StatusInformation(errorIndication=errind.parseError)
 
@@ -517,15 +563,17 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
             msgUserName=securityParameters.getComponentByPosition(3)
         )
 
-        debug.logger & debug.flagSM and debug.logger('processIncomingMsg: cache write securityStateReference %s by msgUserName %s' % (securityStateReference, securityParameters.getComponentByPosition(3)))
+        debug.logger & debug.flagSM and debug.logger(
+            'processIncomingMsg: cache write securityStateReference %s by msgUserName %s' % (
+                securityStateReference, securityParameters.getComponentByPosition(3)))
 
         scopedPduData = msg.getComponentByPosition(3)
 
         # Used for error reporting
-        contextEngineId = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')[0].syntax
+        contextEngineId = mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')[0].syntax
         contextName = null
 
-        snmpEngineID = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')[0].syntax
+        snmpEngineID = mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')[0].syntax
 
         # 3.2.3
         if msgAuthoritativeEngineId != snmpEngineID and \
@@ -533,20 +581,27 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
             if msgAuthoritativeEngineId and \
                     4 < len(msgAuthoritativeEngineId) < 33:
                 # 3.2.3a - cloned user when request was sent
-                debug.logger & debug.flagSM and debug.logger('processIncomingMsg: unsynchronized securityEngineID %r' % (msgAuthoritativeEngineId,))
+                debug.logger & debug.flagSM and debug.logger(
+                    'processIncomingMsg: unsynchronized securityEngineID %r' % (msgAuthoritativeEngineId,))
             else:
                 # 3.2.3b
-                debug.logger & debug.flagSM and debug.logger('processIncomingMsg: peer requested snmpEngineID discovery')
-                usmStatsUnknownEngineIDs, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-USER-BASED-SM-MIB', 'usmStatsUnknownEngineIDs')
+                debug.logger & debug.flagSM and debug.logger(
+                    'processIncomingMsg: peer requested snmpEngineID discovery')
+                usmStatsUnknownEngineIDs, = mibBuilder.importSymbols(
+                    '__SNMP-USER-BASED-SM-MIB', 'usmStatsUnknownEngineIDs')
                 usmStatsUnknownEngineIDs.syntax += 1
-                debug.logger & debug.flagSM and debug.logger('processIncomingMsg: null or malformed msgAuthoritativeEngineId')
-                pysnmpUsmDiscoverable, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__PYSNMP-USM-MIB', 'pysnmpUsmDiscoverable')
+                debug.logger & debug.flagSM and debug.logger(
+                    'processIncomingMsg: null or malformed msgAuthoritativeEngineId')
+                pysnmpUsmDiscoverable, = mibBuilder.importSymbols(
+                    '__PYSNMP-USM-MIB', 'pysnmpUsmDiscoverable')
                 if pysnmpUsmDiscoverable.syntax:
-                    debug.logger & debug.flagSM and debug.logger('processIncomingMsg: starting snmpEngineID discovery procedure')
+                    debug.logger & debug.flagSM and debug.logger(
+                        'processIncomingMsg: starting snmpEngineID discovery procedure')
 
                     # Report original contextName
                     if scopedPduData.getName() != 'plaintext':
-                        debug.logger & debug.flagSM and debug.logger('processIncomingMsg: scopedPduData not plaintext %s' % scopedPduData.prettyPrint())
+                        debug.logger & debug.flagSM and debug.logger(
+                            'processIncomingMsg: scopedPduData not plaintext %s' % scopedPduData.prettyPrint())
                         raise error.StatusInformation(
                             errorIndication=errind.unknownEngineID
                         )
@@ -576,7 +631,9 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
 
         msgUserName = securityParameters.getComponentByPosition(3)
 
-        debug.logger & debug.flagSM and debug.logger('processIncomingMsg: read from securityParams msgAuthoritativeEngineId %r msgUserName %r' % (msgAuthoritativeEngineId, msgUserName))
+        debug.logger & debug.flagSM and debug.logger(
+            'processIncomingMsg: read from securityParams msgAuthoritativeEngineId %r msgUserName %r' % (
+                msgAuthoritativeEngineId, msgUserName))
 
         if msgUserName:
             # 3.2.4
@@ -584,14 +641,17 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                 (usmUserName, usmUserSecurityName, usmUserAuthProtocol,
                  usmUserAuthKeyLocalized, usmUserPrivProtocol,
                  usmUserPrivKeyLocalized) = self.__getUserInfo(
-                     snmpEngine.msgAndPduDsp.mibInstrumController,
-                     msgAuthoritativeEngineId, msgUserName
-                 )
+                    snmpEngine.msgAndPduDsp.mibInstrumController,
+                    msgAuthoritativeEngineId, msgUserName
+                )
                 debug.logger & debug.flagSM and debug.logger('processIncomingMsg: read user info from LCD')
 
             except NoSuchInstanceError:
-                debug.logger & debug.flagSM and debug.logger('processIncomingMsg: unknown securityEngineID %r msgUserName %r' % (msgAuthoritativeEngineId, msgUserName))
-                usmStatsUnknownUserNames, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-USER-BASED-SM-MIB', 'usmStatsUnknownUserNames')
+                debug.logger & debug.flagSM and debug.logger(
+                    'processIncomingMsg: unknown securityEngineID %r msgUserName %r' % (
+                        msgAuthoritativeEngineId, msgUserName))
+                usmStatsUnknownUserNames, = mibBuilder.importSymbols(
+                    '__SNMP-USER-BASED-SM-MIB', 'usmStatsUnknownUserNames')
                 usmStatsUnknownUserNames.syntax += 1
                 raise error.StatusInformation(
                     errorIndication=errind.unknownSecurityName,
@@ -606,7 +666,7 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
 
             except PyAsn1Error:
                 debug.logger & debug.flagSM and debug.logger('processIncomingMsg: %s' % (sys.exc_info()[1],))
-                snmpInGenErrs, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMPv2-MIB', 'snmpInGenErrs')
+                snmpInGenErrs, = mibBuilder.importSymbols('__SNMPv2-MIB', 'snmpInGenErrs')
                 snmpInGenErrs.syntax += 1
                 raise error.StatusInformation(errorIndication=errind.invalidMsg)
         else:
@@ -616,7 +676,9 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
             usmUserPrivProtocol = nopriv.NoPriv.serviceID
             usmUserAuthKeyLocalized = usmUserPrivKeyLocalized = None
 
-        debug.logger & debug.flagSM and debug.logger('processIncomingMsg: now have usmUserName %r usmUserSecurityName %r usmUserAuthProtocol %r usmUserPrivProtocol %r for msgUserName %r' % (usmUserName, usmUserSecurityName, usmUserAuthProtocol, usmUserPrivProtocol, msgUserName))
+        debug.logger & debug.flagSM and debug.logger(
+            'processIncomingMsg: now have usmUserName %r usmUserSecurityName %r usmUserAuthProtocol %r usmUserPrivProtocol %r for msgUserName %r' % (
+                usmUserName, usmUserSecurityName, usmUserAuthProtocol, usmUserPrivProtocol, msgUserName))
 
         # 3.2.11 (moved up here to let Reports be authenticated & encrypted)
         self._cache.pop(securityStateReference)
@@ -647,7 +709,7 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
         snmpEngine.observer.clearExecutionContext(
             snmpEngine, 'rfc3414.processIncomingMsg'
         )
-            
+
         # 3.2.5
         if msgAuthoritativeEngineId == snmpEngineID:
             # Authoritative SNMP engine: make sure securityLevel is sufficient
@@ -671,9 +733,12 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                 if usmUserPrivProtocol != nopriv.NoPriv.serviceID:
                     badSecIndication = 'noAuthNoPriv wanted while priv expected'
             if badSecIndication:
-                usmStatsUnsupportedSecLevels, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-USER-BASED-SM-MIB', 'usmStatsUnsupportedSecLevels')
+                usmStatsUnsupportedSecLevels, = mibBuilder.importSymbols(
+                    '__SNMP-USER-BASED-SM-MIB', 'usmStatsUnsupportedSecLevels')
                 usmStatsUnsupportedSecLevels.syntax += 1
-                debug.logger & debug.flagSM and debug.logger('processIncomingMsg: reporting inappropriate security level for user %s: %s' % (msgUserName, badSecIndication))
+                debug.logger & debug.flagSM and debug.logger(
+                    'processIncomingMsg: reporting inappropriate security level for user %s: %s' % (
+                        msgUserName, badSecIndication))
                 raise error.StatusInformation(
                     errorIndication=errind.unsupportedSecurityLevel,
                     oid=usmStatsUnsupportedSecLevels.name,
@@ -695,14 +760,15 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                 )
 
             try:
-                authenticatedWholeMsg = authHandler.authenticateIncomingMsg(
+                authHandler.authenticateIncomingMsg(
                     usmUserAuthKeyLocalized,
                     securityParameters.getComponentByPosition(4),
                     wholeMsg
                 )
 
             except error.StatusInformation:
-                usmStatsWrongDigests, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-USER-BASED-SM-MIB', 'usmStatsWrongDigests')
+                usmStatsWrongDigests, = mibBuilder.importSymbols(
+                    '__SNMP-USER-BASED-SM-MIB', 'usmStatsWrongDigests')
                 usmStatsWrongDigests.syntax += 1
                 raise error.StatusInformation(
                     errorIndication=errind.authenticationFailure,
@@ -730,38 +796,45 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                 self.__timelineExpQueue[expireAt] = []
             self.__timelineExpQueue[expireAt].append(msgAuthoritativeEngineId)
 
-            debug.logger & debug.flagSM and debug.logger('processIncomingMsg: store timeline for securityEngineID %r' % (msgAuthoritativeEngineId,))
+            debug.logger & debug.flagSM and debug.logger(
+                'processIncomingMsg: store timeline for securityEngineID %r' % (msgAuthoritativeEngineId,))
 
         # 3.2.7
         if securityLevel == 3 or securityLevel == 2:
             if msgAuthoritativeEngineId == snmpEngineID:
                 # Authoritative SNMP engine: use local notion (SF bug #1649032)
-                (snmpEngineBoots, snmpEngineTime) = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineBoots', 'snmpEngineTime')
+                (snmpEngineBoots,
+                 snmpEngineTime) = mibBuilder.importSymbols(
+                    '__SNMP-FRAMEWORK-MIB', 'snmpEngineBoots', 'snmpEngineTime')
                 snmpEngineBoots = snmpEngineBoots.syntax
                 snmpEngineTime = snmpEngineTime.syntax.clone()
                 idleTime = 0
-                debug.logger & debug.flagSM and debug.logger('processIncomingMsg: read snmpEngineBoots (%s), snmpEngineTime (%s) from LCD' % (snmpEngineBoots, snmpEngineTime))
+                debug.logger & debug.flagSM and debug.logger(
+                    'processIncomingMsg: read snmpEngineBoots (%s), snmpEngineTime (%s) from LCD' % (
+                        snmpEngineBoots, snmpEngineTime))
             else:
                 # Non-authoritative SNMP engine: use cached estimates
                 if msgAuthoritativeEngineId in self.__timeline:
                     (snmpEngineBoots, snmpEngineTime,
                      latestReceivedEngineTime,
                      latestUpdateTimestamp) = self.__timeline[
-                         msgAuthoritativeEngineId
-                     ]
+                        msgAuthoritativeEngineId
+                    ]
                     # time passed since last talk with this SNMP engine
-                    idleTime = int(time.time())-latestUpdateTimestamp
-                    debug.logger & debug.flagSM and debug.logger('processIncomingMsg: read timeline snmpEngineBoots %s snmpEngineTime %s for msgAuthoritativeEngineId %r, idle time %s secs' % (snmpEngineBoots, snmpEngineTime, msgAuthoritativeEngineId, idleTime))
+                    idleTime = int(time.time()) - latestUpdateTimestamp
+                    debug.logger & debug.flagSM and debug.logger(
+                        'processIncomingMsg: read timeline snmpEngineBoots %s snmpEngineTime %s for msgAuthoritativeEngineId %r, idle time %s secs' % (
+                            snmpEngineBoots, snmpEngineTime, msgAuthoritativeEngineId, idleTime))
                 else:
                     raise error.ProtocolError('Peer SNMP engine info missing')
 
             # 3.2.7a
             if msgAuthoritativeEngineId == snmpEngineID:
                 if snmpEngineBoots == 2147483647 or \
-                   snmpEngineBoots != msgAuthoritativeEngineBoots or \
-                   abs(idleTime + int(snmpEngineTime) - \
-                       int(msgAuthoritativeEngineTime)) > 150:
-                    usmStatsNotInTimeWindows, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-USER-BASED-SM-MIB', 'usmStatsNotInTimeWindows')
+                        snmpEngineBoots != msgAuthoritativeEngineBoots or \
+                        abs(idleTime + int(snmpEngineTime) - int(msgAuthoritativeEngineTime)) > 150:
+                    usmStatsNotInTimeWindows, = mibBuilder.importSymbols(
+                        '__SNMP-USER-BASED-SM-MIB', 'usmStatsNotInTimeWindows')
                     usmStatsNotInTimeWindows.syntax += 1
                     raise error.StatusInformation(
                         errorIndication=errind.notInTimeWindow,
@@ -776,9 +849,10 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
             # 3.2.7b
             else:
                 # 3.2.7b.1
+                # noinspection PyUnboundLocalVariable
                 if msgAuthoritativeEngineBoots > snmpEngineBoots or \
-                       msgAuthoritativeEngineBoots == snmpEngineBoots and \
-                       msgAuthoritativeEngineTime > latestReceivedEngineTime:
+                        msgAuthoritativeEngineBoots == snmpEngineBoots and \
+                        msgAuthoritativeEngineTime > latestReceivedEngineTime:
                     self.__timeline[msgAuthoritativeEngineId] = (
                         msgAuthoritativeEngineBoots,
                         msgAuthoritativeEngineTime,
@@ -790,14 +864,15 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                         self.__timelineExpQueue[expireAt] = []
                     self.__timelineExpQueue[expireAt].append(msgAuthoritativeEngineId)
 
-                    debug.logger & debug.flagSM and debug.logger('processIncomingMsg: stored timeline msgAuthoritativeEngineBoots %s msgAuthoritativeEngineTime %s for msgAuthoritativeEngineId %r' % (msgAuthoritativeEngineBoots, msgAuthoritativeEngineTime, msgAuthoritativeEngineId))
+                    debug.logger & debug.flagSM and debug.logger(
+                        'processIncomingMsg: stored timeline msgAuthoritativeEngineBoots %s msgAuthoritativeEngineTime %s for msgAuthoritativeEngineId %r' % (
+                            msgAuthoritativeEngineBoots, msgAuthoritativeEngineTime, msgAuthoritativeEngineId))
 
                 # 3.2.7b.2
                 if snmpEngineBoots == 2147483647 or \
-                       msgAuthoritativeEngineBoots < snmpEngineBoots or \
-                       msgAuthoritativeEngineBoots == snmpEngineBoots and \
-                   abs(idleTime + int(snmpEngineTime) - \
-                       int(msgAuthoritativeEngineTime)) > 150:
+                        msgAuthoritativeEngineBoots < snmpEngineBoots or \
+                        msgAuthoritativeEngineBoots == snmpEngineBoots and \
+                        abs(idleTime + int(snmpEngineTime) - int(msgAuthoritativeEngineTime)) > 150:
                     raise error.StatusInformation(
                         errorIndication=errind.notInTimeWindow
                     )
@@ -811,7 +886,7 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                     errorIndication=errind.decryptionError
                 )
             encryptedPDU = scopedPduData.getComponentByPosition(1)
-            if encryptedPDU is None: # no ciphertext
+            if encryptedPDU is None:  # no ciphertext
                 raise error.StatusInformation(
                     errorIndication=errind.decryptionError
                 )
@@ -824,10 +899,12 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                      securityParameters.getComponentByPosition(5)),
                     encryptedPDU
                 )
-                debug.logger & debug.flagSM and debug.logger('processIncomingMsg: PDU deciphered into %s' % debug.hexdump(decryptedData))
+                debug.logger & debug.flagSM and debug.logger(
+                    'processIncomingMsg: PDU deciphered into %s' % debug.hexdump(decryptedData))
 
             except error.StatusInformation:
-                usmStatsDecryptionErrors, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-USER-BASED-SM-MIB', 'usmStatsDecryptionErrors')
+                usmStatsDecryptionErrors, = mibBuilder.importSymbols(
+                    '__SNMP-USER-BASED-SM-MIB', 'usmStatsDecryptionErrors')
                 usmStatsDecryptionErrors.syntax += 1
                 raise error.StatusInformation(
                     errorIndication=errind.decryptionError,
@@ -845,7 +922,8 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                                                  asn1Spec=scopedPduSpec)
 
             except PyAsn1Error:
-                debug.logger & debug.flagSM and debug.logger('processIncomingMsg: scopedPDU decoder failed %s' % sys.exc_info()[0])
+                debug.logger & debug.flagSM and debug.logger(
+                    'processIncomingMsg: scopedPDU decoder failed %s' % sys.exc_info()[0])
                 raise error.StatusInformation(
                     errorIndication=errind.decryptionError
                 )
@@ -862,16 +940,20 @@ class SnmpUSMSecurityModel(AbstractSecurityModel):
                     errorIndication=errind.decryptionError
                 )
 
-        debug.logger & debug.flagSM and debug.logger('processIncomingMsg: scopedPDU decoded %s' % scopedPDU.prettyPrint())
+        debug.logger & debug.flagSM and debug.logger(
+            'processIncomingMsg: scopedPDU decoded %s' % scopedPDU.prettyPrint())
 
         # 3.2.10
         securityName = usmUserSecurityName
 
-        debug.logger & debug.flagSM and debug.logger('processIncomingMsg: cached msgUserName %s info by securityStateReference %s' % (msgUserName, securityStateReference))
+        debug.logger & debug.flagSM and debug.logger(
+            'processIncomingMsg: cached msgUserName %s info by securityStateReference %s' % (
+                msgUserName, securityStateReference))
 
         # Delayed to include details
         if not msgUserName and not msgAuthoritativeEngineId:
-            usmStatsUnknownUserNames, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-USER-BASED-SM-MIB', 'usmStatsUnknownUserNames')
+            usmStatsUnknownUserNames, = mibBuilder.importSymbols(
+                '__SNMP-USER-BASED-SM-MIB', 'usmStatsUnknownUserNames')
             usmStatsUnknownUserNames.syntax += 1
             raise error.StatusInformation(
                 errorIndication=errind.unknownSecurityName,
diff --git a/pysnmp/proto/secmod/rfc3826/priv/aes.py b/pysnmp/proto/secmod/rfc3826/priv/aes.py
index ef22f470..e6541881 100644
--- a/pysnmp/proto/secmod/rfc3826/priv/aes.py
+++ b/pysnmp/proto/secmod/rfc3826/priv/aes.py
@@ -18,31 +18,34 @@ except ImportError:
 
 random.seed()
 
+
 # RFC3826
 
 #
 
 class Aes(base.AbstractEncryptionService):
-    serviceID = (1, 3, 6, 1, 6, 3, 10, 1, 2, 4) # usmAesCfb128Protocol
+    serviceID = (1, 3, 6, 1, 6, 3, 10, 1, 2, 4)  # usmAesCfb128Protocol
     keySize = 16
     _localInt = random.randrange(0, 0xffffffffffffffff)
+
     # 3.1.2.1
     def __getEncryptionKey(self, privKey, snmpEngineBoots, snmpEngineTime):
-        salt = [self._localInt>>56&0xff,
-                self._localInt>>48&0xff,
-                self._localInt>>40&0xff,
-                self._localInt>>32&0xff,
-                self._localInt>>24&0xff,
-                self._localInt>>16&0xff,
-                self._localInt>>8&0xff,
-                self._localInt&0xff]
+        salt = [self._localInt >> 56 & 0xff,
+                self._localInt >> 48 & 0xff,
+                self._localInt >> 40 & 0xff,
+                self._localInt >> 32 & 0xff,
+                self._localInt >> 24 & 0xff,
+                self._localInt >> 16 & 0xff,
+                self._localInt >> 8 & 0xff,
+                self._localInt & 0xff]
 
         if self._localInt == 0xffffffffffffffff:
             self._localInt = 0
         else:
             self._localInt += 1
 
-        return self.__getDecryptionKey(privKey, snmpEngineBoots, snmpEngineTime, salt) + (univ.OctetString(salt).asOctets(),)
+        return self.__getDecryptionKey(privKey, snmpEngineBoots, snmpEngineTime, salt) + (
+        univ.OctetString(salt).asOctets(),)
 
     def __getDecryptionKey(self, privKey, snmpEngineBoots,
                            snmpEngineTime, salt):
@@ -50,14 +53,14 @@ class Aes(base.AbstractEncryptionService):
             int(snmpEngineBoots), int(snmpEngineTime), salt
         )
 
-        iv = [snmpEngineBoots>>24&0xff,
-              snmpEngineBoots>>16&0xff,
-              snmpEngineBoots>>8&0xff,
-              snmpEngineBoots&0xff,
-              snmpEngineTime>>24&0xff,
-              snmpEngineTime>>16&0xff,
-              snmpEngineTime>>8&0xff,
-              snmpEngineTime&0xff] + salt
+        iv = [snmpEngineBoots >> 24 & 0xff,
+              snmpEngineBoots >> 16 & 0xff,
+              snmpEngineBoots >> 8 & 0xff,
+              snmpEngineBoots & 0xff,
+              snmpEngineTime >> 24 & 0xff,
+              snmpEngineTime >> 16 & 0xff,
+              snmpEngineTime >> 8 & 0xff,
+              snmpEngineTime & 0xff] + salt
 
         return privKey[:self.keySize].asOctets(), univ.OctetString(iv).asOctets()
 
@@ -100,7 +103,7 @@ class Aes(base.AbstractEncryptionService):
         aesObj = AES.new(aesKey, AES.MODE_CFB, iv, segment_size=128)
 
         # PyCrypto seems to require padding
-        dataToEncrypt = dataToEncrypt + univ.OctetString((0,) * (16-len(dataToEncrypt)%16)).asOctets()
+        dataToEncrypt = dataToEncrypt + univ.OctetString((0,) * (16 - len(dataToEncrypt) % 16)).asOctets()
 
         ciphertext = aesObj.encrypt(dataToEncrypt)
 
@@ -130,7 +133,7 @@ class Aes(base.AbstractEncryptionService):
         aesObj = AES.new(aesKey, AES.MODE_CFB, iv, segment_size=128)
 
         # PyCrypto seems to require padding
-        encryptedData = encryptedData + univ.OctetString((0,) * (16-len(encryptedData)%16)).asOctets()
+        encryptedData = encryptedData + univ.OctetString((0,) * (16 - len(encryptedData) % 16)).asOctets()
 
         # 3.3.2.4-6
         return aesObj.decrypt(encryptedData.asOctets())