diff --git a/terminatorlib/container.py b/terminatorlib/container.py
index 2afbe913..e715cd1f 100644
--- a/terminatorlib/container.py
+++ b/terminatorlib/container.py
@@ -301,7 +301,7 @@ the tab will also close all terminals within it.')
                 layout['last_active_window'] = False
 
         name = 'child%d' % count
-        count = count + 1
+        count += 1
 
         global_layout[name] = layout
 
@@ -309,7 +309,7 @@ the tab will also close all terminals within it.')
         for child in self.get_children():
             if hasattr(child, 'describe_layout'):
                 count = child.describe_layout(count, name, global_layout, child_order)
-            child_order = child_order + 1
+            child_order += 1
 
         return(count)
 
diff --git a/terminatorlib/notebook.py b/terminatorlib/notebook.py
index 41e8187f..019d976b 100644
--- a/terminatorlib/notebook.py
+++ b/terminatorlib/notebook.py
@@ -133,7 +133,7 @@ class Notebook(Container, Gtk.Notebook):
             elif child['type'] == 'HPaned':
                 page = self.get_nth_page(num)
                 self.split_axis(page, False)
-            num = num + 1
+            num += 1
 
         num = 0
         for child_key in keys:
@@ -151,7 +151,7 @@ class Notebook(Container, Gtk.Notebook):
 
             if  layout.get('last_active_term',  None):
                 self.last_active_term[page] = make_uuid(layout['last_active_term'][num])
-            num = num + 1
+            num += 1
 
         if 'active_page' in layout:
             # Need to do it later, or layout changes result
@@ -442,7 +442,7 @@ class Notebook(Container, Gtk.Notebook):
         """Clean up any empty tabs and if we only have one tab left, die"""
         numpages = self.get_n_pages()
         while numpages > 0:
-            numpages = numpages - 1
+            numpages -= 1
             page = self.get_nth_page(numpages)
             if not page:
                 dbg('Removing empty page: %d' % numpages)
diff --git a/terminatorlib/paned.py b/terminatorlib/paned.py
index 0eea6d61..b1791347 100644
--- a/terminatorlib/paned.py
+++ b/terminatorlib/paned.py
@@ -211,12 +211,12 @@ class Paned(Container):
                     childset = [child, [], 0, curr]
                     curr[1].append(childset)
                     toproc.append(childset)
-                    number_splits = number_splits+1
+                    number_splits += 1
                 else:
                     curr[1].append([None,[], 1, None])
                     p = curr
                     while p:
-                        p[2] = p[2] + 1
+                        p[2] += 1
                         p = p[3]
                     # (1c) If Shift modifier, redistribute lower sections too
                     if recurse_down and \
@@ -231,7 +231,7 @@ class Paned(Container):
         single_size = (avail_pixels - (number_splits * handle_size)) / (number_splits + 1)
         arr_sizes = [single_size]*(number_splits+1)
         for i in range(avail_pixels % (number_splits + 1)):
-            arr_sizes[i] = arr_sizes[i] + 1
+            arr_sizes[i] += 1
         #5 Descend down setting the handle position to s
         #  (Has to handle nesting properly)
         toproc = [tree]
@@ -410,7 +410,7 @@ class Paned(Container):
                 self.split_axis(terminal, False)
             else:
                 err('unknown child type: %s' % child['type'])
-            num = num + 1
+            num += 1
 
         self.get_child1().create_layout(children[keys[0]])
         self.get_child2().create_layout(children[keys[1]])
diff --git a/terminatorlib/plugins/custom_commands.py b/terminatorlib/plugins/custom_commands.py
index e624358e..d7b2eb5a 100644
--- a/terminatorlib/plugins/custom_commands.py
+++ b/terminatorlib/plugins/custom_commands.py
@@ -118,13 +118,13 @@ class CustomCommandsMenu(plugin.MenuItem):
         item['position'] = i
 
         config.plugin_set(self.__class__.__name__, name, item)
-        i = i + 1
+        i += 1
       config.save()
 
     def _execute(self, widget, data):
       command = data['command']
       if command[-1] != '\n':
-        command = command + '\n'
+        command += '\n'
       for terminal in data['terminals']:
         terminal.vte.feed_child(command.encode())
 
@@ -253,7 +253,7 @@ class CustomCommandsMenu(plugin.MenuItem):
                             'name': name,
                             'command' : command}
           iter = store.iter_next(iter)
-          i = i + 1
+          i += 1
       
 
     def on_toggled(self, widget, path, data):
diff --git a/terminatorlib/plugins/run_cmd_on_match.py b/terminatorlib/plugins/run_cmd_on_match.py
index e9010203..2d0ca1eb 100644
--- a/terminatorlib/plugins/run_cmd_on_match.py
+++ b/terminatorlib/plugins/run_cmd_on_match.py
@@ -154,7 +154,7 @@ class RunCmdOnMatchMenu(plugin.MenuItem):
             item['position'] = i
 
             config.plugin_set(self.__class__.__name__, regexp, item)
-            i = i + 1
+            i += 1
         config.save()
         self._load_configured_handlers()
 
@@ -186,7 +186,7 @@ class RunCmdOnMatchMenu(plugin.MenuItem):
     def _execute(self, widget, data):
       command = data['command']
       if command[-1] != '\n':
-        command = command + '\n'
+        command += '\n'
       for terminal in data['terminals']:
         terminal.vte.feed_child(command.encode())
 
@@ -315,7 +315,7 @@ class RunCmdOnMatchMenu(plugin.MenuItem):
                             'regexp': regexp,
                             'command' : command}
           iter = store.iter_next(iter)
-          i = i + 1
+          i += 1
 
 
     def on_toggled(self, widget, path, data):
diff --git a/terminatorlib/prefseditor.py b/terminatorlib/prefseditor.py
index 90e2b04c..ade79b37 100755
--- a/terminatorlib/prefseditor.py
+++ b/terminatorlib/prefseditor.py
@@ -1331,7 +1331,7 @@ class PrefsEditor:
         if newprofile in values:
             i = 1
             while newprofile in values:
-                i = i + 1
+                i += 1
                 newprofile = '%s %d' % (name, i)
 
         if self.config.add_profile(newprofile, toclone):
@@ -1392,7 +1392,7 @@ class PrefsEditor:
         if name in values:
             i = 0
             while name in values:
-                i = i + 1
+                i += 1
                 name = '%s %d' % (_('New Layout'), i)
 
         if self.config.add_layout(name, current_layout):
@@ -1874,7 +1874,7 @@ class LayoutEditor:
             self.profile_ids_to_profile[i] = profile
             self.profile_profile_to_ids[profile] = i
             chooser.append_text(profile)
-            i = i + 1
+            i += 1
 
     def on_layout_selection_changed(self, selection):
         """A different layout was selected"""
diff --git a/terminatorlib/terminal.py b/terminatorlib/terminal.py
index 016ff214..d323654e 100644
--- a/terminatorlib/terminal.py
+++ b/terminatorlib/terminal.py
@@ -1725,7 +1725,7 @@ class Terminal(Gtk.VBox):
             layout['title'] = title
         layout['uuid'] = self.uuid
         name = 'terminal%d' % count
-        count = count + 1
+        count += 1
         global_layout[name] = layout
         return count
 
diff --git a/terminatorlib/terminator.py b/terminatorlib/terminator.py
index 729c7513..b0c61ef2 100644
--- a/terminatorlib/terminator.py
+++ b/terminatorlib/terminator.py
@@ -238,7 +238,7 @@ class Terminator(Borg):
         # Loop over the layout until we have consumed it, or hit 1000 loops.
         # This is a stupid artificial limit, but it's safe.
         while len(layout) > 0 and count < 1000:
-            count = count + 1
+            count += 1
             if count == 1000:
                 err('hit maximum loop boundary. THIS IS VERY LIKELY A BUG')
             for obj in list(layout.keys()):
diff --git a/terminatorlib/window.py b/terminatorlib/window.py
index d2d581b2..9029d68d 100644
--- a/terminatorlib/window.py
+++ b/terminatorlib/window.py
@@ -647,10 +647,10 @@ class Window(Container, Gtk.Window):
             rect = terminal.get_allocation()
             if rect.x == 0:
                 cols, rows = terminal.get_size()
-                row_sum = row_sum + rows
+                row_sum += rows
             if rect.y == 0:
                 cols, rows = terminal.get_size()
-                column_sum = column_sum + cols
+                column_sum += cols
 
         if column_sum == 0 or row_sum == 0:
             dbg('column_sum=%s,row_sum=%s. No terminals found in >=1 axis' %
@@ -812,12 +812,12 @@ class Window(Container, Gtk.Window):
             if page == 0:
                 page = numpages
             else:
-                page = page - 1
+                page -= 1
         elif direction == 'right':
             if page == numpages - 1:
                 page = 0
             else:
-                page = page + 1
+                page += 1
         else:
             err('unknown direction: %s' % direction)
             return
@@ -920,7 +920,7 @@ class Window(Container, Gtk.Window):
             i = 2
             while i < len(child['children']):
                 self.tab_new()
-                i = i + 1
+                i += 1
         elif child['type'] == 'Terminal':
             pass
         else:
diff --git a/tests/test_signalman.py b/tests/test_signalman.py
index 0044e11d..f8b5fb23 100755
--- a/tests/test_signalman.py
+++ b/tests/test_signalman.py
@@ -45,7 +45,7 @@ class TestWidget():
         self.count = 0
 
     def connect(self, signal, handler, *args):
-        self.count = self.count + 1
+        self.count += 1
         self.signals[self.count] = signal
         return(self.count)