diff --git a/src/Bookmarks.py b/src/Bookmarks.py
index 48c4aceb3..1a6b9e437 100644
--- a/src/Bookmarks.py
+++ b/src/Bookmarks.py
@@ -281,7 +281,7 @@ class Bookmarks :
         self.namemodel.remove(the_iter)
         self.modified = True
         if row > 0:
-            row = row - 1
+            row -= 1
         self.namemodel.select_row(row)
 
     def up_clicked(self, obj):
diff --git a/src/DataViews/GeoView.py b/src/DataViews/GeoView.py
index d96bb1d29..d93876e04 100644
--- a/src/DataViews/GeoView.py
+++ b/src/DataViews/GeoView.py
@@ -524,10 +524,10 @@ class GeoView(HtmlView):
         modulo = intvl - ( intvl % 10 )
         if modulo == 0:
             modulo = 10
-        self.minyear = ( self.minyear - ( self.minyear % 10 ) )
-        self.maxyear = ( self.maxyear - ( self.maxyear % 10 ) )
+        self.minyear -= self.minyear % 10
+        self.maxyear -= self.maxyear % 10
         self.yearint = (self.maxyear-self.minyear)/self.maxgen
-        self.yearint = ( self.yearint - ( self.yearint % modulo ) )
+        self.yearint -= self.yearint % modulo
         if self.yearint == 0:
             self.yearint = 10
         self.mapview.write("<script>\n")
@@ -929,13 +929,13 @@ class GeoView(HtmlView):
                 if tfc > self.maxyear:
                     self.maxyear = tfc
         if tfa < 0.0:
-            tfa = tfa - 0.00000001
+            tfa -= 0.00000001
         else:
-            tfa = tfa + 0.00000001
+            tfa += 0.00000001
         if tfb < 0.0:
-            tfb = tfb - 0.00000001
+            tfb -= 0.00000001
         else:
-            tfb = tfb + 0.00000001
+            tfb += 0.00000001
         if self.minlat == 0.0:
             self.minlat = tfa
         if tfa < self.minlat:
diff --git a/src/DataViews/GrampletView.py b/src/DataViews/GrampletView.py
index 306552c20..c55d1af47 100644
--- a/src/DataViews/GrampletView.py
+++ b/src/DataViews/GrampletView.py
@@ -810,7 +810,7 @@ class GuiGramplet(object):
                 else:
                     markup = text[i+2:i+stop].upper() # close tag
                     markup_pos[markup][-1].append(r)
-                    i = i + stop + 1
+                    i += stop + 1
             elif text[i] == "<":
                 # start of start tag
                 stop = text[i:].find(">")
@@ -821,7 +821,7 @@ class GuiGramplet(object):
                 else:
                     markup, attr = parse_tag_attr(text[i+1:i+stop])
                     markup_pos[markup].append([r, attr])
-                    i = i + stop + 1
+                    i += stop + 1
             elif text[i] == "\\":
                 retval += text[i+1]
                 r += 1
diff --git a/src/FilterEditor/_EditRule.py b/src/FilterEditor/_EditRule.py
index d08f20bdb..225a626c0 100644
--- a/src/FilterEditor/_EditRule.py
+++ b/src/FilterEditor/_EditRule.py
@@ -494,7 +494,7 @@ class EditRule(ManagedWindow.ManagedWindow):
                 tlist.append(t)
                 table.attach(l, 1, 2, pos, pos+1, gtk.FILL, 0, 5, 5)
                 table.attach(t, 2, 3, pos, pos+1, gtk.EXPAND|gtk.FILL, 0, 5, 5)
-                pos = pos + 1
+                pos += 1
             self.notebook.append_page(table, gtk.Label(class_obj.name))
             self.class2page[class_obj] = self.page_num
             self.page_num = self.page_num + 1
diff --git a/src/PlaceUtils.py b/src/PlaceUtils.py
index 4f3158a51..45e247648 100644
--- a/src/PlaceUtils.py
+++ b/src/PlaceUtils.py
@@ -89,10 +89,7 @@ def __convert_structure_to_float(sign, degs, mins=0, secs=0.0) :
         v += float(mins) / 60.
     if secs is not None:
         v += secs / 3600.
-    if sign == "-":
-        v = v * -1.
-
-    return v
+    return -v if sign == "-" else v
 
 def __convert_using_float_repr(stringValue):
     """ helper function that tries to convert the string using the float
diff --git a/src/PluginUtils/_PluginWindows.py b/src/PluginUtils/_PluginWindows.py
index ee55b070c..f101195dd 100644
--- a/src/PluginUtils/_PluginWindows.py
+++ b/src/PluginUtils/_PluginWindows.py
@@ -465,7 +465,7 @@ class ToolManagedWindowBase(ManagedWindow.ManagedWindow):
                 else:
                     table.attach(widget, 2, 3, row, row+1,
                                  yoptions=gtk.SHRINK)
-                row = row + 1
+                row += 1
         self.notebook.show_all()
 
     #------------------------------------------------------------------------
diff --git a/src/RecentFiles.py b/src/RecentFiles.py
index cbd7770d1..5e2c09836 100644
--- a/src/RecentFiles.py
+++ b/src/RecentFiles.py
@@ -169,7 +169,7 @@ class RecentFiles(object):
         xml_file.write('<RecentFiles>\n')
         index = 0
         for item in self.gramps_recent_files:
-            index = index + 1
+            index += 1
             if index > MAX_GRAMPS_ITEMS:
                 break
             xml_file.write('  <RecentItem>\n')
diff --git a/src/ReportBase/_Bibliography.py b/src/ReportBase/_Bibliography.py
index 480a815da..32f7fe4e5 100644
--- a/src/ReportBase/_Bibliography.py
+++ b/src/ReportBase/_Bibliography.py
@@ -87,11 +87,11 @@ class Citation(object):
         number_of_letters = int(math.log(float(ref_count), float(letter_count)))+1
         # Exclude index for number_of_letters-1
         for n in range(1, number_of_letters-1):
-            ref_count = ref_count - pow(letter_count, n) 
+            ref_count -= pow(letter_count, n) 
         # Adjust number_of_letters for new index
         number_of_letters = int(math.log(float(ref_count), float(letter_count))) +1
         for n in range(1, number_of_letters):
-            x_ref_count = x_ref_count - pow(letter_count, n) 
+            x_ref_count -= pow(letter_count, n) 
         for letter in range(1, number_of_letters):
             index = x_ref_count  / pow(letter_count, letter)  % letter_count
             key += string.ascii_lowercase[ index ]
diff --git a/src/ReportBase/_DrawReportDialog.py b/src/ReportBase/_DrawReportDialog.py
index 23b9322c0..053b81217 100644
--- a/src/ReportBase/_DrawReportDialog.py
+++ b/src/ReportBase/_DrawReportDialog.py
@@ -70,7 +70,7 @@ class _DrawFormatComboBox(gtk.ComboBox):
             self.store.append(row=[name])
             if plugin.get_extension() == active:
                 active_index = index
-            index = index + 1
+            index += 1
         self.set_active(active_index)
 
     def get_active_plugin(self):
diff --git a/src/ReportBase/_GraphvizReportDialog.py b/src/ReportBase/_GraphvizReportDialog.py
index d9666d8f8..55bf68003 100644
--- a/src/ReportBase/_GraphvizReportDialog.py
+++ b/src/ReportBase/_GraphvizReportDialog.py
@@ -871,7 +871,7 @@ class GraphvizFormatComboBox(gtk.ComboBox):
             self.store.append(row=[name])
             if item['type'] == active:
                 active_index = index
-            index = index + 1
+            index += 1
         self.set_active(active_index)
 
     def get_label(self):
diff --git a/src/ReportBase/_ReportDialog.py b/src/ReportBase/_ReportDialog.py
index cd9f42aeb..8b4d0c216 100644
--- a/src/ReportBase/_ReportDialog.py
+++ b/src/ReportBase/_ReportDialog.py
@@ -370,7 +370,7 @@ class ReportDialog(ManagedWindow.ManagedWindow):
                 else:
                     table.attach(widget, 2, 3, row, row+1,
                                  yoptions=gtk.SHRINK)
-                row = row + 1
+                row += 1
                 
     def setup_main_options(self):
         if "" in self.frames:
diff --git a/src/ReportBase/_ReportUtils.py b/src/ReportBase/_ReportUtils.py
index 5561a66b4..2d03ef323 100644
--- a/src/ReportBase/_ReportUtils.py
+++ b/src/ReportBase/_ReportUtils.py
@@ -1533,7 +1533,7 @@ def draw_wedge(doc,  style,  centerx,  centery,  radius,  start_angle,
             x = centerx + cos(angle) * short_radius
             y = centery + sin(angle) * short_radius
             p.append((x, y))
-            angle = angle - radiansdelta
+            angle -= radiansdelta
     doc.draw_path(style, p)
 
     delta = (eangle - sangle) / 2.0
diff --git a/src/ReportBase/_StyleEditor.py b/src/ReportBase/_StyleEditor.py
index 3eea1ec25..638ac3293 100644
--- a/src/ReportBase/_StyleEditor.py
+++ b/src/ReportBase/_StyleEditor.py
@@ -122,7 +122,7 @@ class StyleListDisplay(object):
             if style == "default":
                 continue
             self.list.add([style])
-            index = index + 1
+            index += 1
 
     def on_add_clicked(self, obj):
         """Called with the ADD button is clicked. Invokes the StyleEditor to
diff --git a/src/ReportBase/_TextReportDialog.py b/src/ReportBase/_TextReportDialog.py
index 46cb86c61..d97ca4865 100644
--- a/src/ReportBase/_TextReportDialog.py
+++ b/src/ReportBase/_TextReportDialog.py
@@ -71,7 +71,7 @@ class _TextFormatComboBox(gtk.ComboBox):
             self.store.append(row=[name])
             if plugin.get_extension() == active:
                 active_index = index
-            index = index + 1
+            index += 1
         self.set_active(active_index)
         
     def get_active_plugin(self):
diff --git a/src/docgen/TextBufDoc.py b/src/docgen/TextBufDoc.py
index cc05342af..6aa8ffeb5 100644
--- a/src/docgen/TextBufDoc.py
+++ b/src/docgen/TextBufDoc.py
@@ -296,10 +296,10 @@ class TextBufDoc(BaseDoc, TextDoc):
 
         self.in_cell = 1
         self.cellnum = self.cellnum + span
-        span = span - 1
+        span -= 1
         while span:
             self.cell_widths[self.cellnum-span] = 0
-            span = span - 1
+            span -= 1
             
     #--------------------------------------------------------------------
     #
diff --git a/src/gen/lib/date.py b/src/gen/lib/date.py
index 6629d923a..a2b2ba94e 100644
--- a/src/gen/lib/date.py
+++ b/src/gen/lib/date.py
@@ -561,7 +561,7 @@ class Span(object):
                 diff = 0
                 while eDate >> date2 and diff > -60:
                     diff -= 1
-                    eDate = eDate - (0, 0, abs(diff))
+                    eDate -= (0, 0, abs(diff))
                 if diff == -60:
                     return (-1, -1, -1)
                 if self.negative:
diff --git a/src/plugins/BookReport.py b/src/plugins/BookReport.py
index 551597600..c4a11c29a 100644
--- a/src/plugins/BookReport.py
+++ b/src/plugins/BookReport.py
@@ -1078,7 +1078,7 @@ class _BookFormatComboBox(gtk.ComboBox):
             self.store.append(row=[name])
             if plugin.get_extension() == active:
                 active_index = index
-            index = index + 1
+            index += 1
         self.set_active(active_index)
 
     def get_active_plugin(self):
diff --git a/src/plugins/docgen/AsciiDoc.py b/src/plugins/docgen/AsciiDoc.py
index b9fba0bec..78568c422 100644
--- a/src/plugins/docgen/AsciiDoc.py
+++ b/src/plugins/docgen/AsciiDoc.py
@@ -317,12 +317,12 @@ class AsciiDoc(BaseDoc,TextDoc):
     def start_cell(self,style_name,span=1):
         self.in_cell = 1
         self.cellnum = self.cellnum + span
-        span = span - 1
+        span -= 1
         while span:
             self.cell_widths[self.cellnum] += \
                 self.cell_widths[self.cellnum-span]
             self.cell_widths[self.cellnum-span] = 0
-            span = span - 1
+            span -= 1
             
 
     #--------------------------------------------------------------------
diff --git a/src/plugins/docgen/RTFDoc.py b/src/plugins/docgen/RTFDoc.py
index fc857ceb4..14778b42c 100644
--- a/src/plugins/docgen/RTFDoc.py
+++ b/src/plugins/docgen/RTFDoc.py
@@ -103,11 +103,11 @@ class RTFDoc(BaseDoc,TextDoc):
             if fgcolor not in self.color_map:
                 self.color_map[fgcolor] = index
                 self.f.write('\\red%d\\green%d\\blue%d;' % fgcolor)
-                index = index + 1
+                index += 1
             if bgcolor not in self.color_map:
                 self.f.write('\\red%d\\green%d\\blue%d;' % bgcolor)
                 self.color_map[bgcolor] = index
-                index = index + 1
+                index += 1
         self.f.write('}\n')
         self.f.write('\\kerning0\\cf0\\viewkind1')
         self.f.write('\\paperw%d' % twips(self.paper.get_size().get_width()))
diff --git a/src/plugins/docgen/SvgDrawDoc.py b/src/plugins/docgen/SvgDrawDoc.py
index 97e93f0cd..2ae7c07ff 100644
--- a/src/plugins/docgen/SvgDrawDoc.py
+++ b/src/plugins/docgen/SvgDrawDoc.py
@@ -254,7 +254,7 @@ class SvgDrawDoc(BaseDoc, DrawDoc):
         p = style_sheet.get_paragraph_style(para_name)
         font = p.get_font()
         width = self.string_width(font, text) / 72
-        x = x - width
+        x -= width
         self.draw_text(style, text, x, y)
 
 def units(val):
diff --git a/src/plugins/drawreport/FanChart.py b/src/plugins/drawreport/FanChart.py
index b95562ed1..5f24e2d9b 100644
--- a/src/plugins/drawreport/FanChart.py
+++ b/src/plugins/drawreport/FanChart.py
@@ -183,7 +183,7 @@ class FanChart(Report):
                 style_sheet = self.doc.get_style_sheet()
                 fontsize = pt2cm(style_sheet.get_paragraph_style('FC-Title').get_font().get_size())
                 # y is vertical distance to center of circle, move center down 1 fontsize
-                y = y + fontsize
+                y += fontsize
                 # min_XY is the diamter of the circle, subtract two fontsize
                 # so we dont draw outside bottom of the paper
                 min_xy = min(min_xy,y-2*fontsize)
diff --git a/src/plugins/drawreport/StatisticsChart.py b/src/plugins/drawreport/StatisticsChart.py
index 55738fa4f..f60796a53 100644
--- a/src/plugins/drawreport/StatisticsChart.py
+++ b/src/plugins/drawreport/StatisticsChart.py
@@ -591,9 +591,9 @@ class StatisticsChart(Report):
     
         # output data...
         radius = middle - 2*margin
-        yoffset = yoffset + margin + radius
+        yoffset += margin + radius
         ReportUtils.draw_pie_chart(self.doc, middle_w, yoffset, radius, chart_data, -90)
-        yoffset = yoffset + radius + 2*margin
+        yoffset += radius + 2*margin
         if middle == middle_h:   # Landscape
             legendx = 1.0
             yoffset = margin
diff --git a/src/plugins/gramplet/FanChartGramplet.py b/src/plugins/gramplet/FanChartGramplet.py
index bafb5d974..4b30508c7 100644
--- a/src/plugins/gramplet/FanChartGramplet.py
+++ b/src/plugins/gramplet/FanChartGramplet.py
@@ -395,7 +395,7 @@ class FanChartWidget(gtk.Widget):
             self.angle[generation][selected] = [current, current + slice, 
                                                 male,state]
             self.shrink_parents(generation + 1, selected, current)
-            current = current + slice
+            current += slice
         start,stop,male,state = self.angle[generation][selected+1]
         if state in [self.NORMAL, self.EXPANDED]:
             slice = (stop - start) / 2.0
diff --git a/src/plugins/gramplet/StatsGramplet.py b/src/plugins/gramplet/StatsGramplet.py
index 4c73dedc8..0215a4227 100644
--- a/src/plugins/gramplet/StatsGramplet.py
+++ b/src/plugins/gramplet/StatsGramplet.py
@@ -85,7 +85,7 @@ class StatsGramplet(Gramplet):
             photo = database.get_object_from_handle(photo_id)
             fullname = media_path_full(database, photo.get_path())
             try:
-                bytes = bytes + posixpath.getsize(fullname)
+                bytes += posixpath.getsize(fullname)
             except:
                 notfound.append(photo.get_path())
 
diff --git a/src/plugins/import/ImportProGen.py b/src/plugins/import/ImportProGen.py
index a90c124c5..ad0cf275a 100644
--- a/src/plugins/import/ImportProGen.py
+++ b/src/plugins/import/ImportProGen.py
@@ -193,7 +193,7 @@ def _get_mem_text(mems, i):
     if i <= 0:
         return ''
 
-    i = i - 1
+    i -= 1
     recno = mems[i][0]
     text = mems[i][1].decode('cp850')
     if recno != 0:
diff --git a/src/plugins/rel/rel_nl.py b/src/plugins/rel/rel_nl.py
index f458721d9..da3faf850 100644
--- a/src/plugins/rel/rel_nl.py
+++ b/src/plugins/rel/rel_nl.py
@@ -393,7 +393,7 @@ class RelationshipCalculator(Relationship.RelationshipCalculator):
             going sideways in a branch as the nieces/newphews going downward
             from your brother/sisters. This used to be called "kozijn"
         """
-        removed = removed - 1
+        removed -= 1
         if removed > len(_removed_level)-1:
             return "verre %s%sneef (kozijn, %d graden)" % (inlaw, step, 
                                                            removed)
@@ -408,7 +408,7 @@ class RelationshipCalculator(Relationship.RelationshipCalculator):
             going sideways in a branch as the nieces/newphews going downward
             from your brother/sisters.  This used to be called "kozijn"
         """
-        removed = removed - 1
+        removed -= 1
         if removed > len(_removed_level)-1:
             return "verre %s%snicht (kozijn, %d graden)" % (inlaw, step, 
                                                            removed)
diff --git a/src/plugins/textreport/DetAncestralReport.py b/src/plugins/textreport/DetAncestralReport.py
index 30c9b6ffd..222f62245 100644
--- a/src/plugins/textreport/DetAncestralReport.py
+++ b/src/plugins/textreport/DetAncestralReport.py
@@ -172,7 +172,7 @@ class DetAncestorReport(Report):
                 mark = IndexMark(text, INDEX_TYPE_TOC, 2)
                 self.doc.write_text(text, mark)
                 self.doc.end_paragraph()
-                generation = generation + 1
+                generation += 1
                 if self.childref:
                     self.prev_gen_handles = self.gen_handles.copy()
                     self.gen_handles.clear()
diff --git a/src/plugins/textreport/FamilyGroup.py b/src/plugins/textreport/FamilyGroup.py
index bebb08ae0..1c1d49675 100644
--- a/src/plugins/textreport/FamilyGroup.py
+++ b/src/plugins/textreport/FamilyGroup.py
@@ -419,7 +419,7 @@ class FamilyGroup(Report):
                 else:
                     spouse_id = family.get_father_handle()
                 if spouse_id:
-                    spouse_count = spouse_count + 1
+                    spouse_count += 1
 
         self.doc.start_row()
         if spouse_count != 0 or self.missingInfo or death is not None or birth is not None:
@@ -462,7 +462,7 @@ class FamilyGroup(Report):
             index = 0
             for family_handle in person.get_family_handle_list():
                 m = None
-                index = index + 1
+                index += 1
                 family = self.database.get_family_from_handle(family_handle)
 
                 for event_ref in family.get_event_ref_list():
@@ -562,7 +562,7 @@ class FamilyGroup(Report):
             index = 1
             for child_ref in family.get_child_ref_list():
                 self.dump_child(index,child_ref.ref)
-                index = index + 1
+                index += 1
             self.doc.end_table()
 
         if self.recursive:
diff --git a/src/plugins/textreport/Summary.py b/src/plugins/textreport/Summary.py
index 414e3ac1a..d3ad3355f 100644
--- a/src/plugins/textreport/Summary.py
+++ b/src/plugins/textreport/Summary.py
@@ -111,32 +111,32 @@ class SummaryReport(Report):
             # Count people with media.
             length = len(person.get_media_list())
             if length > 0:
-                with_media = with_media + 1
+                with_media += 1
             
             # Count people with incomplete names.
             name = person.get_primary_name()
             if name.get_first_name() == "" or name.get_surname() == "":
-                incomp_names = incomp_names + 1
+                incomp_names += 1
                 
             # Count people without families.
             if (not person.get_main_parents_family_handle()) and \
                (not len(person.get_family_handle_list())):
-                disconnected = disconnected + 1
+                disconnected += 1
             
             # Count missing birthdays.
             birth_ref = person.get_birth_ref()
             if birth_ref:
                 birth = self.__db.get_event_from_handle(birth_ref.ref)
                 if not DateHandler.get_date(birth):
-                    missing_bday = missing_bday + 1
+                    missing_bday += 1
             else:
-                missing_bday = missing_bday + 1
+                missing_bday += 1
                 
             # Count genders.
             if person.get_gender() == gen.lib.Person.FEMALE:
-                females = females + 1
+                females += 1
             elif person.get_gender() == gen.lib.Person.MALE:
-                males = males + 1
+                males += 1
             else:
                 unknowns += 1
                 
@@ -212,9 +212,8 @@ class SummaryReport(Report):
         for media_id in self.__db.get_media_object_handles():
             media = self.__db.get_object_from_handle(media_id)
             try:
-                size_in_bytes = size_in_bytes + posixpath.getsize(
-                                                    media_path_full(self.__db, 
-                                                    media.get_path()))
+                size_in_bytes += posixpath.getsize(
+                                 media_path_full(self.__db, media.get_path()))
             except:
                 notfound.append(media.get_path())
                 
diff --git a/src/plugins/tool/EventCmp.py b/src/plugins/tool/EventCmp.py
index 56110f73d..02e967762 100644
--- a/src/plugins/tool/EventCmp.py
+++ b/src/plugins/tool/EventCmp.py
@@ -275,9 +275,9 @@ class DisplayChart(ManagedWindow.ManagedWindow):
                 column.set_sort_column_id(model_index)
                 self.eventlist.append_column(column)
                 # This one numbers the tree columns: increment on new column
-                tree_index = tree_index + 1
+                tree_index += 1
             # This one numbers the model columns: always increment
-            model_index = model_index + 1
+            model_index += 1
 
         model = gtk.ListStore(*mylist)
         self.eventlist.set_model(model)
diff --git a/src/widgets/validatedmaskedentry.py b/src/widgets/validatedmaskedentry.py
index 652c912d2..f70c4ab16 100644
--- a/src/widgets/validatedmaskedentry.py
+++ b/src/widgets/validatedmaskedentry.py
@@ -220,9 +220,9 @@ class Tooltip(gtk.Window):
 
         if ((y + h + widget.allocation.height + Tooltip.BORDER_WIDTH) >
             monitor.y + monitor.height):
-            y = y - h - Tooltip.BORDER_WIDTH
+            y -= h + Tooltip.BORDER_WIDTH
         else:
-            y = y + widget.allocation.height + Tooltip.BORDER_WIDTH
+            y += widget.allocation.height + Tooltip.BORDER_WIDTH
 
         return x, y