Index: src/sas/sasgui/plottools/PlotPanel.py
===================================================================
--- src/sas/sasgui/plottools/PlotPanel.py	(revision 235f514ba93b57fa63e44309f182acef0b98bb55)
+++ src/sas/sasgui/plottools/PlotPanel.py	(revision 7432acb919f4013119ca918a73350297e0d4c93f)
@@ -154,9 +154,9 @@
         self.selectedText = None
         #User scale
-        if xtransform != None:
+        if xtransform is not None:
             self.xLabel = xtransform
         else:
             self.xLabel = "log10(x)"
-        if ytransform != None:
+        if ytransform is not None:
             self.yLabel = ytransform
         else:
@@ -360,5 +360,5 @@
                     return
 
-            if ax != None:
+            if ax is not None:
                 self.xInit, self.yInit = event.xdata, event.ydata
                 try:
@@ -392,5 +392,5 @@
         Set legend alpha
         """
-        if self.legend != None:
+        if self.legend is not None:
             self.legend.legendPatch.set_alpha(alpha)
 
@@ -461,5 +461,5 @@
             # User has clicked on text and is dragging
             ax = event.inaxes
-            if ax != None:
+            if ax is not None:
                 # Only move text if mouse is within axes
                 self.selectedText.set_position((event.xdata, event.ydata))
@@ -476,5 +476,5 @@
         if self.leftdown == True and self.mousemotion == True:
             ax = event.inaxes
-            if ax != None:  # the dragging is perform inside the figure
+            if ax is not None:  # the dragging is perform inside the figure
                 self.xFinal, self.yFinal = event.xdata, event.ydata
                 # Check whether this is the first point
@@ -576,5 +576,5 @@
         step = event.step
 
-        if ax != None:
+        if ax is not None:
             # Event occurred inside a plotting area
             lo, hi = ax.get_xlim()
@@ -935,5 +935,5 @@
         # reset postion
         self.position = None
-        if self.graph.selected_plottable != None:
+        if self.graph.selected_plottable is not None:
             self.graph.selected_plottable = None
 
@@ -959,5 +959,5 @@
                                               prop=FontProperties(size=10),
                                               loc=self.legendLoc)
-            if self.legend != None:
+            if self.legend is not None:
                 self.legend.set_picker(self.legend_picker)
                 self.legend.set_axes(self.subplot)
@@ -989,5 +989,5 @@
                                           prop=FontProperties(size=10),
                                           loc=self.legendLoc)
-        if self.legend != None:
+        if self.legend is not None:
             self.legend.set_picker(self.legend_picker)
             self.legend.set_axes(self.subplot)
@@ -1010,5 +1010,5 @@
         pos_x = 0
         pos_y = 0
-        if self.position != None:
+        if self.position is not None:
             pos_x, pos_y = self.position
         else:
@@ -1035,5 +1035,5 @@
                     self.subplot.figure.canvas.draw_idle()
             except:
-                if self.parent != None:
+                if self.parent is not None:
                     msg = "Add Text: Error. Check your property values..."
                     wx.PostEvent(self.parent, StatusEvent(status=msg))
@@ -1069,5 +1069,5 @@
             self.xaxis_tick = xaxis_font
 
-        if self.data != None:
+        if self.data is not None:
             # 2D
             self.xaxis(self.xaxis_label, self.xaxis_unit, \
@@ -1116,5 +1116,5 @@
             self.yaxis_tick = yaxis_font
 
-        if self.data != None:
+        if self.data is not None:
             # 2D
             self.yaxis(self.yaxis_label, self.yaxis_unit, \
@@ -1155,5 +1155,5 @@
                 label_temp = textdial.getText()
                 if label_temp.count("\%s" % "\\") > 0:
-                    if self.parent != None:
+                    if self.parent is not None:
                         msg = "Add Label: Error. Can not use double '\\' "
                         msg += "characters..."
@@ -1162,5 +1162,5 @@
                     label = label_temp
             except:
-                if self.parent != None:
+                if self.parent is not None:
                     msg = "Add Label: Error. Check your property values..."
                     wx.PostEvent(self.parent, StatusEvent(status=msg))
@@ -1180,5 +1180,5 @@
         num_text = len(self.textList)
         if num_text < 1:
-            if self.parent != None:
+            if self.parent is not None:
                 msg = "Remove Text: Nothing to remove.  "
                 wx.PostEvent(self.parent, StatusEvent(status=msg))
@@ -1190,9 +1190,9 @@
             text_remove = txt.get_text()
             txt.remove()
-            if self.parent != None:
+            if self.parent is not None:
                 msg = "Removed Text: '%s'. " % text_remove
                 wx.PostEvent(self.parent, StatusEvent(status=msg))
         except:
-            if self.parent != None:
+            if self.parent is not None:
                 msg = "Remove Text: Error occurred. "
                 wx.PostEvent(self.parent, StatusEvent(status=msg))
@@ -1250,5 +1250,5 @@
                                         prop=FontProperties(size=10),
                                         loc=self.legendLoc)
-                if self.legend != None:
+                if self.legend is not None:
                     self.legend.set_picker(self.legend_picker)
                     self.legend.set_axes(self.subplot)
@@ -1279,5 +1279,5 @@
         if font:
             self.subplot.set_xlabel(label, fontproperties=font, color=color)
-            if t_font != None:
+            if t_font is not None:
                 for tick in self.subplot.xaxis.get_major_ticks():
                     tick.label.set_fontproperties(t_font)
@@ -1300,5 +1300,5 @@
         if font:
             self.subplot.set_ylabel(label, fontproperties=font, color=color)
-            if t_font != None:
+            if t_font is not None:
                 for tick_label in self.subplot.get_yticklabels():
                     tick_label.set_fontproperties(t_font)
@@ -1327,5 +1327,5 @@
         from plottable_interactor import PointInteractor
         p = PointInteractor(self, self.subplot, zorder=zorder, id=id)
-        if p.markersize != None:
+        if p.markersize is not None:
             markersize = p.markersize
         p.points(x, y, dx=dx, dy=dy, color=color, symbol=symbol, zorder=zorder,
@@ -1363,7 +1363,7 @@
 
         # Convert tuple (lo,hi) to array [(x-lo),(hi-x)]
-        if dx != None and type(dx) == type(()):
+        if dx is not None and type(dx) == type(()):
             dx = nx.vstack((x - dx[0], dx[1] - x)).transpose()
-        if dy != None and type(dy) == type(()):
+        if dy is not None and type(dy) == type(()):
             dy = nx.vstack((y - dy[0], dy[1] - y)).transpose()
         if dx is None and dy is None:
@@ -1772,5 +1772,5 @@
             # control axis labels from the panel itself
             yname, yunits = item.get_yaxis()
-            if self.yaxis_label != None:
+            if self.yaxis_label is not None:
                 yname = self.yaxis_label
                 yunits = self.yaxis_unit
@@ -1779,5 +1779,5 @@
                 self.yaxis_unit = yunits
             xname, xunits = item.get_xaxis()
-            if self.xaxis_label != None:
+            if self.xaxis_label is not None:
                 xname = self.xaxis_label
                 xunits = self.xaxis_unit
Index: src/sas/sasgui/plottools/TextDialog.py
===================================================================
--- src/sas/sasgui/plottools/TextDialog.py	(revision 959eb0181ad06828a748f04512f953aad5b31659)
+++ src/sas/sasgui/plottools/TextDialog.py	(revision 7432acb919f4013119ca918a73350297e0d4c93f)
@@ -41,5 +41,5 @@
         style_box = wx.BoxSizer(wx.HORIZONTAL)
         # tcA
-        if unit != None:
+        if unit is not None:
             styles = wx.TAB_TRAVERSAL
             height = -1
@@ -130,5 +130,5 @@
                        0, wx.TOP, 5)
         family_box.Add(self.font_size, 0, 0)
-        if unit_box != None:
+        if unit_box is not None:
             family_box.Add((_BOX_WIDTH / 2, -1))
             family_box.Add(tick_label_text, 0, 0)
@@ -159,5 +159,5 @@
         text_box.Add(self.text_string)
         vbox.Add(text_box, 0, wx.EXPAND, 15)
-        if unit_box != None:
+        if unit_box is not None:
             unit_box.Add(unit_text, 0, 0)
             unit_box.Add(self.unit_ctrl, 0, 0)
Index: src/sas/sasgui/plottools/arrow3d.py
===================================================================
--- src/sas/sasgui/plottools/arrow3d.py	(revision 959eb0181ad06828a748f04512f953aad5b31659)
+++ src/sas/sasgui/plottools/arrow3d.py	(revision 7432acb919f4013119ca918a73350297e0d4c93f)
@@ -29,5 +29,5 @@
         self.base = base
 
-        if base != None:
+        if base is not None:
             # To turn the updating off during dragging
             base.canvas.mpl_connect('button_press_event', self.on_left_down)
Index: src/sas/sasgui/plottools/canvas.py
===================================================================
--- src/sas/sasgui/plottools/canvas.py	(revision 463e7ffce130ae386f93cd18b87a1120743e88b5)
+++ src/sas/sasgui/plottools/canvas.py	(revision 7432acb919f4013119ca918a73350297e0d4c93f)
@@ -153,5 +153,5 @@
         """
         self.panel.subplot.grid(self.panel.grid_on)
-        if self.panel.legend != None and self.panel.legend_pos_loc:
+        if self.panel.legend is not None and self.panel.legend_pos_loc:
             self.panel.legend._loc = self.panel.legend_pos_loc
         self.idletimer.Restart(5, *args, **kwargs)  # Delay by 5 ms
Index: src/sas/sasgui/plottools/fitDialog.py
===================================================================
--- src/sas/sasgui/plottools/fitDialog.py	(revision 235f514ba93b57fa63e44309f182acef0b98bb55)
+++ src/sas/sasgui/plottools/fitDialog.py	(revision 7432acb919f4013119ca918a73350297e0d4c93f)
@@ -579,5 +579,5 @@
                     self.I0_tctr.SetValue(format_number(val))
             if self.Rgerr_tctr.IsShown():
-                if rg != None and rg != 0:
+                if rg is not None and rg != 0:
                     value = format_number(3 * float(errA) / (2 * rg))
                 else:
@@ -593,5 +593,5 @@
                 self.Diameter_tctr.SetValue(value)
             if self.Diametererr_tctr.IsShown():
-                if rg != None and rg != 0:
+                if rg is not None and rg != 0:
                     value = format_number(8 * float(errA) / _diam)
                 else:
Index: src/sas/sasgui/plottools/plottable_interactor.py
===================================================================
--- src/sas/sasgui/plottools/plottable_interactor.py	(revision ac07a3acc20dbf79c564bf642aece71a02c2c862)
+++ src/sas/sasgui/plottools/plottable_interactor.py	(revision 7432acb919f4013119ca918a73350297e0d4c93f)
@@ -56,7 +56,7 @@
             markersize = self.markersize
         # Convert tuple (lo,hi) to array [(x-lo),(hi-x)]
-        if dx != None and type(dx) == type(()):
+        if dx is not None and type(dx) == type(()):
             dx = nx.vstack((x - dx[0], dx[1] - x)).transpose()
-        if dy != None and type(dy) == type(()):
+        if dy is not None and type(dy) == type(()):
             dy = nx.vstack((y - dy[0], dy[1] - y)).transpose()
 
Index: src/sas/sasgui/plottools/plottables.py
===================================================================
--- src/sas/sasgui/plottools/plottables.py	(revision ac07a3acc20dbf79c564bf642aece71a02c2c862)
+++ src/sas/sasgui/plottools/plottables.py	(revision 7432acb919f4013119ca918a73350297e0d4c93f)
@@ -682,5 +682,5 @@
         has_err_y = not (dy is None or len(dy) == 0)
 
-        if(x != None) and (y != None):
+        if(x is not None) and (y is not None):
             if not dx is None and not len(dx) == 0 and not len(x) == len(dx):
                 msg = "Plottable.View: Given x and dx are not"
@@ -864,5 +864,5 @@
         if self.dy is None:
             self.dy = np.zeros(len(self.y))
-        if xmin != None and xmax != None:
+        if xmin is not None and xmax is not None:
             for i in range(len(self.x)):
                 if self.x[i] >= xmin and self.x[i] <= xmax:
Index: src/sas/sasgui/plottools/transform.py
===================================================================
--- src/sas/sasgui/plottools/transform.py	(revision 235f514ba93b57fa63e44309f182acef0b98bb55)
+++ src/sas/sasgui/plottools/transform.py	(revision 7432acb919f4013119ca918a73350297e0d4c93f)
@@ -188,5 +188,5 @@
 
     """
-    if  dx != None:
+    if  dx is not None:
         err = 2 * x * dx
         return math.fabs(err)
@@ -204,5 +204,5 @@
     """
     if x > 0:
-        if dx != None:
+        if dx is not None:
             err = dx / (2 * math.sqrt(x))
         else:
@@ -222,5 +222,5 @@
 
     """
-    if dx != None:
+    if dx is not None:
         err = 4 * math.pow(x, 3) * dx
         return math.fabs(err)
@@ -238,5 +238,5 @@
     """
     if x > 0:
-        if dx != None:
+        if dx is not None:
             err = dx / (4 * math.pow(x, 3 / 4))
         else:
