diff --git a/lib/core/gui.py b/lib/core/gui.py
index 6bf7d9587..3143b892f 100644
--- a/lib/core/gui.py
+++ b/lib/core/gui.py
@@ -65,7 +65,7 @@ def runGui(parser):
             _tkinter_ttk.Notebook.__init__(self, master, **kw)
             self.bind("<<NotebookTabChanged>>", self._on_tab_changed)
 
-        def _on_tab_changed(self,event):
+        def _on_tab_changed(self, event):
             event.widget.update_idletasks()
 
             tab = event.widget.nametowidget(event.widget.select())
@@ -76,7 +76,7 @@ def runGui(parser):
 
     # Reference: https://www.holadevs.com/pregunta/64750/change-selected-tab-color-in-ttknotebook
     style = _tkinter_ttk.Style()
-    settings = {"TNotebook.Tab": {"configure": {"padding": [5, 1], "background": "#fdd57e" }, "map": {"background": [("selected", "#C70039"), ("active", "#fc9292")], "foreground": [("selected", "#ffffff"), ("active", "#000000")]}}}
+    settings = {"TNotebook.Tab": {"configure": {"padding": [5, 1], "background": "#fdd57e"}, "map": {"background": [("selected", "#C70039"), ("active", "#fc9292")], "foreground": [("selected", "#ffffff"), ("active", "#000000")]}}}
     style.theme_create("custom", parent="alt", settings=settings)
     style.theme_use("custom")
 
@@ -189,7 +189,7 @@ def runGui(parser):
         while alive:
             line = ""
             try:
-                #line = queue.get_nowait()
+                # line = queue.get_nowait()
                 line = queue.get(timeout=.1)
                 text.insert(_tkinter.END, line)
             except _queue.Empty:
diff --git a/lib/core/profiling.py b/lib/core/profiling.py
index 0fe0836d6..2282d9448 100644
--- a/lib/core/profiling.py
+++ b/lib/core/profiling.py
@@ -27,7 +27,7 @@ def profile(profileOutputFile=None, dotOutputFile=None, imageOutputFile=None):
         import pydot
     except ImportError as ex:
         errMsg = "profiling requires third-party libraries ('%s') " % getSafeExString(ex)
-        errMsg += "(Hint: 'sudo apt-get install python-pydot python-pyparsing python-profiler graphviz')"
+        errMsg += "(Hint: 'sudo apt install python-pydot python-pyparsing python-profiler graphviz')"
         logger.error(errMsg)
 
         return
@@ -84,7 +84,7 @@ def profile(profileOutputFile=None, dotOutputFile=None, imageOutputFile=None):
         pydotGraph.write_png(imageOutputFile)
     except OSError:
         errMsg = "profiling requires graphviz installed "
-        errMsg += "(Hint: 'sudo apt-get install graphviz')"
+        errMsg += "(Hint: 'sudo apt install graphviz')"
         logger.error(errMsg)
     else:
         infoMsg = "displaying interactive graph with xdot library"
diff --git a/lib/core/update.py b/lib/core/update.py
index 9cd588263..4314575ff 100644
--- a/lib/core/update.py
+++ b/lib/core/update.py
@@ -136,6 +136,6 @@ def update():
             infoMsg += "https://github.com/sqlmapproject/sqlmap/downloads"
         else:
             infoMsg = "for Linux platform it's recommended "
-            infoMsg += "to install a standard 'git' package (e.g.: 'sudo apt-get install git')"
+            infoMsg += "to install a standard 'git' package (e.g.: 'sudo apt install git')"
 
         logger.info(infoMsg)
diff --git a/lib/utils/api.py b/lib/utils/api.py
index 84d2327e1..468c09c03 100644
--- a/lib/utils/api.py
+++ b/lib/utils/api.py
@@ -705,7 +705,7 @@ def server(host=RESTAPI_DEFAULT_ADDRESS, port=RESTAPI_DEFAULT_PORT, adapter=REST
             errMsg += "List of supported adapters: %s" % ', '.join(sorted(list(server_names.keys())))
         else:
             errMsg = "Server support for adapter '%s' is not installed on this system " % adapter
-            errMsg += "(Note: you can try to install it with 'sudo apt-get install python-%s' or 'sudo pip install %s')" % (adapter, adapter)
+            errMsg += "(Note: you can try to install it with 'sudo apt install python-%s' or 'sudo pip install %s')" % (adapter, adapter)
         logger.critical(errMsg)
 
 def _client(url, options=None):
diff --git a/lib/utils/brute.py b/lib/utils/brute.py
index 4b75a0b5d..b1589dafe 100644
--- a/lib/utils/brute.py
+++ b/lib/utils/brute.py
@@ -163,7 +163,7 @@ def tableExists(tableFile, regex=None):
         if not threadData.shared.files:
             warnMsg = "no table(s) found"
             if conf.db:
-                 warnMsg += " for database '%s'" % conf.db
+                warnMsg += " for database '%s'" % conf.db
             logger.warn(warnMsg)
         else:
             for item in threadData.shared.files:
diff --git a/thirdparty/keepalive/keepalive.py b/thirdparty/keepalive/keepalive.py
index 86bcdd877..4647f1f7c 100644
--- a/thirdparty/keepalive/keepalive.py
+++ b/thirdparty/keepalive/keepalive.py
@@ -107,9 +107,11 @@ from __future__ import print_function
 
 try:
     from thirdparty.six.moves import http_client as _http_client
+    from thirdparty.six.moves import range as _range
     from thirdparty.six.moves import urllib as _urllib
 except ImportError:
     from six.moves import http_client as _http_client
+    from six.moves import range as _range
     from six.moves import urllib as _urllib
 
 import socket
@@ -569,7 +571,7 @@ def fetch(N, url, delay=0):
     import time
     lens = []
     starttime = time.time()
-    for i in range(N):
+    for i in _range(N):
         if delay and i > 0: time.sleep(delay)
         fo = _urllib.request.urlopen(url)
         foo = fo.read()