Index: src/sas/sasgui/perspectives/fitting/fitting.py
===================================================================
--- src/sas/sasgui/perspectives/fitting/fitting.py	(revision 463e7ffce130ae386f93cd18b87a1120743e88b5)
+++ src/sas/sasgui/perspectives/fitting/fitting.py	(revision 235f514ba93b57fa63e44309f182acef0b98bb55)
@@ -386,5 +386,5 @@
         help for setting list of the edit model menu labels
         """
-        if menu == None:
+        if menu is None:
             menu = self.edit_custom_model
         list_fnames = os.listdir(models.find_plugins_dir())
@@ -1125,5 +1125,5 @@
         page = self.fit_panel.set_data(data)
         # page could be None when loading state files
-        if page == None:
+        if page is None:
             return page
         #append Data1D to the panel containing its theory
@@ -1193,5 +1193,5 @@
         """
         # case that uid is not specified
-        if uid == None:
+        if uid is None:
             for page_id in self.page_finder.keys():
                 self.page_finder[page_id].schedule_tofit(value)
@@ -1231,5 +1231,5 @@
         """
         panel = self.plot_panel
-        if panel == None:
+        if panel is None:
             raise ValueError, "Fitting:_onSelect: NonType panel"
         Plugin.on_perspective(self, event=event)
@@ -1335,5 +1335,5 @@
                 if not correct_result or res.fitness is None or \
                     not np.isfinite(res.fitness) or \
-                        np.any(res.pvec == None) or not \
+                        np.any(res.pvec is None) or not \
                         np.all(np.isfinite(res.pvec)):
                     data_name = str(None)
@@ -1526,5 +1526,5 @@
                 if res.fitness is None or \
                     not np.isfinite(res.fitness) or \
-                        np.any(res.pvec == None) or \
+                        np.any(res.pvec is None) or \
                     not np.all(np.isfinite(res.pvec)):
                     fit_msg += "\nFitting did not converge!!!"
@@ -1587,5 +1587,5 @@
         """
         event.Skip()
-        if self.menu1 == None:
+        if self.menu1 is None:
             return
         menu_item = self.menu1.FindItemById(self.id_reset_flag)
@@ -1646,5 +1646,5 @@
         caption = evt.caption
         enable_smearer = evt.enable_smearer
-        if model == None:
+        if model is None:
             return
         if uid not in self.page_finder.keys():
@@ -1698,5 +1698,5 @@
         new_plot.title = data.name
         new_plot.group_id = data.group_id
-        if new_plot.group_id == None:
+        if new_plot.group_id is None:
             new_plot.group_id = data.group_id
         new_plot.id = data_id
@@ -2002,11 +2002,11 @@
         chisqr = None
         #to compute chisq make sure data has valid data
-        # return None if data == None
-        if not check_data_validity(data_copy) or data_copy == None:
+        # return None if data is None
+        if not check_data_validity(data_copy) or data_copy is None:
             return chisqr
 
         # Get data: data I, theory I, and data dI in order
         if data_copy.__class__.__name__ == "Data2D":
-            if index == None:
+            if index is None:
                 index = np.ones(len(data_copy.data), dtype=bool)
             if weight != None:
@@ -2017,5 +2017,5 @@
             fn = data_copy.data[index]
             theory_data = self.page_finder[page_id].get_theory_data(fid=data_copy.id)
-            if theory_data == None:
+            if theory_data is None:
                 return chisqr
             gn = theory_data.data[index]
@@ -2023,9 +2023,9 @@
         else:
             # 1 d theory from model_thread is only in the range of index
-            if index == None:
+            if index is None:
                 index = np.ones(len(data_copy.y), dtype=bool)
             if weight != None:
                 data_copy.dy = weight
-            if data_copy.dy == None or data_copy.dy == []:
+            if data_copy.dy is None or data_copy.dy == []:
                 dy = np.ones(len(data_copy.y))
             else:
@@ -2037,5 +2037,5 @@
 
             theory_data = self.page_finder[page_id].get_theory_data(fid=data_copy.id)
-            if theory_data == None:
+            if theory_data is None:
                 return chisqr
             gn = theory_data.y
@@ -2080,5 +2080,5 @@
             theory_data = self.page_finder[page_id].get_theory_data(fid=data_copy.id)
             gn = theory_data.data
-            if weight == None:
+            if weight is None:
                 en = data_copy.err_data
             else:
@@ -2101,8 +2101,8 @@
         else:
             # 1 d theory from model_thread is only in the range of index
-            if data_copy.dy == None or data_copy.dy == []:
+            if data_copy.dy is None or data_copy.dy == []:
                 dy = np.ones(len(data_copy.y))
             else:
-                if weight == None:
+                if weight is None:
                     dy = np.ones(len(data_copy.y))
                 ## Set consitently w/AbstractFitengine:
@@ -2142,5 +2142,5 @@
         ##group_id specify on which panel to plot this data
         group_id = self.page_finder[page_id].get_graph_id()
-        if group_id == None:
+        if group_id is None:
             group_id = data.group_id
         new_plot.group_id = "res" + str(group_id)
