diff --git a/.pylintrc b/.pylintrc
index 39cf72c05..ec855adbc 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -70,7 +70,6 @@ enable=import-error,
        unused-wildcard-import,
        global-variable-not-assigned,
        undefined-loop-variable,
-       global-statement,
        global-at-module-level,
        bad-open-mode,
        redundant-unittest-assert,
diff --git a/lib/controller/checks.py b/lib/controller/checks.py
index 49a9f3c58..d3e7a0f88 100644
--- a/lib/controller/checks.py
+++ b/lib/controller/checks.py
@@ -561,7 +561,7 @@ def checkSqlInjection(place, parameter, value):
                                         candidates = trueSet - falseSet - errorSet
 
                                         if candidates:
-                                            candidates = sorted(candidates, key=lambda _: len(_))
+                                            candidates = sorted(candidates, key=len)
                                             for candidate in candidates:
                                                 if re.match(r"\A[\w.,! ]+\Z", candidate) and ' ' in candidate and candidate.strip() and len(candidate) > CANDIDATE_SENTENCE_MIN_LENGTH:
                                                     conf.string = candidate
@@ -595,7 +595,7 @@ def checkSqlInjection(place, parameter, value):
                                         candidates = filterNone(_.strip() if _.strip() in trueRawResponse and _.strip() not in falseRawResponse else None for _ in (trueSet - falseSet - errorSet))
 
                                         if candidates:
-                                            candidates = sorted(candidates, key=lambda _: len(_))
+                                            candidates = sorted(candidates, key=len)
                                             for candidate in candidates:
                                                 if re.match(r"\A\w+\Z", candidate):
                                                     break
@@ -609,7 +609,7 @@ def checkSqlInjection(place, parameter, value):
                                             candidates = filterNone(_.strip() if _.strip() in falseRawResponse and _.strip() not in trueRawResponse else None for _ in (falseSet - trueSet))
 
                                             if candidates:
-                                                candidates = sorted(candidates, key=lambda _: len(_))
+                                                candidates = sorted(candidates, key=len)
                                                 for candidate in candidates:
                                                     if re.match(r"\A\w+\Z", candidate):
                                                         break
diff --git a/lib/core/bigarray.py b/lib/core/bigarray.py
index 95c602711..a6f6ac24d 100644
--- a/lib/core/bigarray.py
+++ b/lib/core/bigarray.py
@@ -53,7 +53,7 @@ class BigArray(list):
     List-like class used for storing large amounts of data (disk cached)
     """
 
-    def __init__(self, items=[]):
+    def __init__(self, items=None):
         self.chunks = [[]]
         self.chunk_length = sys.maxsize
         self.cache = None
@@ -61,7 +61,7 @@ class BigArray(list):
         self._os_remove = os.remove
         self._size_counter = 0
 
-        for item in items:
+        for item in (items or []):
             self.append(item)
 
     def append(self, value):
@@ -139,12 +139,6 @@ class BigArray(list):
         self.__init__()
         self.chunks, self.filenames = state
 
-    def __getslice__(self, i, j):
-        i = max(0, len(self) + i if i < 0 else i)
-        j = min(len(self), len(self) + j if j < 0 else j)
-
-        return BigArray(self[_] for _ in xrange(i, j))
-
     def __getitem__(self, y):
         if y < 0:
             y += len(self)
diff --git a/lib/core/common.py b/lib/core/common.py
index ee753692d..e50c57d60 100644
--- a/lib/core/common.py
+++ b/lib/core/common.py
@@ -2328,22 +2328,21 @@ def initCommonOutputs():
     kb.commonOutputs = {}
     key = None
 
-    with openFile(paths.COMMON_OUTPUTS, 'r') as f:
-        for line in f:
-            if line.find('#') != -1:
-                line = line[:line.find('#')]
+    for line in openFile(paths.COMMON_OUTPUTS, 'r'):
+        if line.find('#') != -1:
+            line = line[:line.find('#')]
 
-            line = line.strip()
+        line = line.strip()
 
-            if len(line) > 1:
-                if line.startswith('[') and line.endswith(']'):
-                    key = line[1:-1]
-                elif key:
-                    if key not in kb.commonOutputs:
-                        kb.commonOutputs[key] = set()
+        if len(line) > 1:
+            if line.startswith('[') and line.endswith(']'):
+                key = line[1:-1]
+            elif key:
+                if key not in kb.commonOutputs:
+                    kb.commonOutputs[key] = set()
 
-                    if line not in kb.commonOutputs[key]:
-                        kb.commonOutputs[key].add(line)
+                if line not in kb.commonOutputs[key]:
+                    kb.commonOutputs[key].add(line)
 
 def getFileItems(filename, commentPrefix='#', unicoded=True, lowercase=False, unique=False):
     """
@@ -3921,7 +3920,7 @@ def normalizeUnicode(value, charset=string.printable[:string.printable.find(' ')
 
     # Reference: http://www.peterbe.com/plog/unicode-to-ascii
 
-    >>> normalizeUnicode(u'\u0161u\u0107uraj') == u'sucuraj'
+    >>> normalizeUnicode(u'\\u0161u\\u0107uraj') == u'sucuraj'
     True
     >>> normalizeUnicode(getUnicode(decodeHex("666f6f00626172"))) == u'foobar'
     True
@@ -4096,7 +4095,7 @@ def expandMnemonics(mnemonics, parser, args):
                 debugMsg = "mnemonic '%s' resolved to %s). " % (name, found)
                 logger.debug(debugMsg)
             else:
-                found = sorted(options.keys(), key=lambda x: len(x))[0]
+                found = sorted(options.keys(), key=len)[0]
                 warnMsg = "detected ambiguity (mnemonic '%s' can be resolved to any of: %s). " % (name, ", ".join("'%s'" % key for key in options))
                 warnMsg += "Resolved to shortest of those ('%s')" % found
                 logger.warn(warnMsg)
@@ -5043,7 +5042,6 @@ def parseRequestFile(reqFile, checkParams=True):
 def getSafeExString(ex, encoding=None):
     """
     Safe way how to get the proper exception represtation as a string
-    (Note: errors to be avoided: 1) "%s" % Exception(u'\u0161') and 2) "%s" % str(Exception(u'\u0161'))
 
     >>> getSafeExString(SqlmapBaseException('foobar')) == 'foobar'
     True
diff --git a/lib/core/datatype.py b/lib/core/datatype.py
index 0fc30d817..860347a49 100644
--- a/lib/core/datatype.py
+++ b/lib/core/datatype.py
@@ -184,15 +184,15 @@ class OrderedSet(collections.MutableSet):
     def __contains__(self, key):
         return key in self.map
 
-    def add(self, key):
-        if key not in self.map:
+    def add(self, value):
+        if value not in self.map:
             end = self.end
             curr = end[1]
-            curr[2] = end[1] = self.map[key] = [key, curr, end]
+            curr[2] = end[1] = self.map[value] = [value, curr, end]
 
-    def discard(self, key):
-        if key in self.map:
-            key, prev, next = self.map.pop(key)
+    def discard(self, value):
+        if value in self.map:
+            value, prev, next = self.map.pop(value)
             prev[2] = next
             next[1] = prev
 
diff --git a/lib/core/dump.py b/lib/core/dump.py
index 0a1b3979e..6c6580075 100644
--- a/lib/core/dump.py
+++ b/lib/core/dump.py
@@ -468,8 +468,7 @@ class Dump(object):
                                 shutil.copyfile(dumpFileName, candidate)
                             except IOError:
                                 pass
-                            finally:
-                                break
+                            break
                         else:
                             count += 1
 
diff --git a/lib/core/option.py b/lib/core/option.py
index 4b0087a6a..9fef8f3e6 100644
--- a/lib/core/option.py
+++ b/lib/core/option.py
@@ -838,6 +838,7 @@ def _setPreprocessFunctions():
     if conf.preprocess:
         for script in re.split(PARAMETER_SPLITTING_REGEX, conf.preprocess):
             found = False
+            function = None
 
             script = safeFilepathEncode(script.strip())
 
diff --git a/lib/core/replication.py b/lib/core/replication.py
index 837839289..e68710618 100644
--- a/lib/core/replication.py
+++ b/lib/core/replication.py
@@ -79,9 +79,9 @@ class Replication(object):
                 errMsg = "wrong number of columns used in replicating insert"
                 raise SqlmapValueException(errMsg)
 
-        def execute(self, sql, parameters=[]):
+        def execute(self, sql, parameters=None):
             try:
-                self.parent.cursor.execute(sql, parameters)
+                self.parent.cursor.execute(sql, parameters or [])
             except sqlite3.OperationalError as ex:
                 errMsg = "problem occurred ('%s') while accessing sqlite database " % getSafeExString(ex, UNICODE_ENCODING)
                 errMsg += "located at '%s'. Please make sure that " % self.parent.dbpath
diff --git a/lib/core/settings.py b/lib/core/settings.py
index 34351bc41..988c37df5 100644
--- a/lib/core/settings.py
+++ b/lib/core/settings.py
@@ -18,7 +18,7 @@ from lib.core.enums import OS
 from thirdparty.six import unichr as _unichr
 
 # sqlmap version (<major>.<minor>.<month>.<monthly commit>)
-VERSION = "1.3.5.154"
+VERSION = "1.3.5.155"
 TYPE = "dev" if VERSION.count('.') > 2 and VERSION.split('.')[-1] != '0' else "stable"
 TYPE_COLORS = {"dev": 33, "stable": 90, "pip": 34}
 VERSION_STRING = "sqlmap/%s#%s" % ('.'.join(VERSION.split('.')[:-1]) if VERSION.count('.') > 2 and VERSION.split('.')[-1] == '0' else VERSION, TYPE)
diff --git a/lib/parse/banner.py b/lib/parse/banner.py
index 77ae798f6..6d5a60f29 100644
--- a/lib/parse/banner.py
+++ b/lib/parse/banner.py
@@ -53,11 +53,11 @@ class MSSQLBannerHandler(ContentHandler):
         elif name == "servicepack":
             self._inServicePack = True
 
-    def characters(self, data):
+    def characters(self, content):
         if self._inVersion:
-            self._version += sanitizeStr(data)
+            self._version += sanitizeStr(content)
         elif self._inServicePack:
-            self._servicePack += sanitizeStr(data)
+            self._servicePack += sanitizeStr(content)
 
     def endElement(self, name):
         if name == "signature":
diff --git a/lib/utils/getch.py b/lib/utils/getch.py
index 733fdf570..f3b16f9e5 100644
--- a/lib/utils/getch.py
+++ b/lib/utils/getch.py
@@ -57,10 +57,10 @@ class _GetchMacCarbon(object):
     """
     def __init__(self):
         import Carbon
-        Carbon.Evt  # see if it has this (in Unix, it doesn't)
+
+        _ = Carbon.Evt  # see if it has this (in Unix, it doesn't)
 
     def __call__(self):
-        import Carbon
         if Carbon.Evt.EventAvail(0x0008)[0] == 0:  # 0x0008 is the keyDownMask
             return ''
         else:
diff --git a/lib/utils/hash.py b/lib/utils/hash.py
index 508410603..ef521fa40 100644
--- a/lib/utils/hash.py
+++ b/lib/utils/hash.py
@@ -635,7 +635,7 @@ def attackDumpedTable():
         col_passwords = set()
         attack_dict = {}
 
-        for column in sorted(columns, key=lambda _: len(_), reverse=True):
+        for column in sorted(columns, key=len, reverse=True):
             if column and column.lower() in COMMON_USER_COLUMNS:
                 col_user = column
                 break
diff --git a/lib/utils/timeout.py b/lib/utils/timeout.py
index 4f661769f..a08f1f2c3 100644
--- a/lib/utils/timeout.py
+++ b/lib/utils/timeout.py
@@ -11,7 +11,7 @@ from lib.core.data import logger
 from lib.core.enums import CUSTOM_LOGGING
 from lib.core.enums import TIMEOUT_STATE
 
-def timeout(func, args=(), kwargs={}, duration=1, default=None):
+def timeout(func, args=None, kwargs=None, duration=1, default=None):
     class InterruptableThread(threading.Thread):
         def __init__(self):
             threading.Thread.__init__(self)
@@ -20,7 +20,7 @@ def timeout(func, args=(), kwargs={}, duration=1, default=None):
 
         def run(self):
             try:
-                self.result = func(*args, **kwargs)
+                self.result = func(*(args or ()), **(kwargs or {}))
                 self.timeout_state = TIMEOUT_STATE.NORMAL
             except Exception as ex:
                 logger.log(CUSTOM_LOGGING.TRAFFIC_IN, ex)
diff --git a/lib/utils/xrange.py b/lib/utils/xrange.py
index 8bdb407b9..962f7f625 100644
--- a/lib/utils/xrange.py
+++ b/lib/utils/xrange.py
@@ -66,9 +66,6 @@ class xrange(object):
     def __hash__(self):
         return hash(self._slice)
 
-    def __cmp__(self, other):
-        return (cmp(type(self), type(other)) or cmp(self._slice, other._slice))
-
     def __repr__(self):
         return '%s(%r, %r, %r)' % (type(self).__name__, self.start, self.stop, self.step)