Index: src/sas/sascalc/dataloader/readers/ascii_reader.py
===================================================================
--- src/sas/sascalc/dataloader/readers/ascii_reader.py	(revision 959eb0181ad06828a748f04512f953aad5b31659)
+++ src/sas/sascalc/dataloader/readers/ascii_reader.py	(revision 235f514ba93b57fa63e44309f182acef0b98bb55)
@@ -128,10 +128,10 @@
                         if new_lentoks > 2:
                             _dy = float(toks[2])
-                        has_error_dy = False if _dy == None else True
+                        has_error_dy = False if _dy is None else True
 
                         # If a 4th row is present, consider it dx
                         if new_lentoks > 3:
                             _dx = float(toks[3])
-                        has_error_dx = False if _dx == None else True
+                        has_error_dx = False if _dx is None else True
 
                         # Delete the previously stored lines of data candidates if
Index: src/sas/sascalc/dataloader/readers/cansas_reader.py
===================================================================
--- src/sas/sascalc/dataloader/readers/cansas_reader.py	(revision 63d773c420797b9a40dbfc28b1e602df82410cae)
+++ src/sas/sascalc/dataloader/readers/cansas_reader.py	(revision 235f514ba93b57fa63e44309f182acef0b98bb55)
@@ -807,5 +807,5 @@
         :param data1d: presumably a Data1D object
         """
-        if self.current_dataset == None:
+        if self.current_dataset is None:
             x_vals = np.empty(0)
             y_vals = np.empty(0)
@@ -895,5 +895,5 @@
         # Write the file
         file_ref = open(filename, 'w')
-        if self.encoding == None:
+        if self.encoding is None:
             self.encoding = "UTF-8"
         doc.write(file_ref, encoding=self.encoding,
@@ -1015,5 +1015,5 @@
         :param entry_node: lxml node ElementTree object to be appended to
         """
-        if datainfo.run == None or datainfo.run == []:
+        if datainfo.run is None or datainfo.run == []:
             datainfo.run.append(RUN_NAME_DEFAULT)
             datainfo.run_name[RUN_NAME_DEFAULT] = RUN_NAME_DEFAULT
@@ -1213,5 +1213,5 @@
                                  str(datainfo.source.name))
         self.append(source, instr)
-        if datainfo.source.radiation == None or datainfo.source.radiation == '':
+        if datainfo.source.radiation is None or datainfo.source.radiation == '':
             datainfo.source.radiation = "neutron"
         self.write_node(source, "radiation", datainfo.source.radiation)
@@ -1254,5 +1254,5 @@
         :param instr: lxml node ElementTree object to be appended to
         """
-        if datainfo.collimation == [] or datainfo.collimation == None:
+        if datainfo.collimation == [] or datainfo.collimation is None:
             coll = Collimation()
             datainfo.collimation.append(coll)
@@ -1299,5 +1299,5 @@
         :param inst: lxml instrument node to be appended to
         """
-        if datainfo.detector == None or datainfo.detector == []:
+        if datainfo.detector is None or datainfo.detector == []:
             det = Detector()
             det.name = ""
Index: src/sas/sascalc/dataloader/readers/danse_reader.py
===================================================================
--- src/sas/sascalc/dataloader/readers/danse_reader.py	(revision 959eb0181ad06828a748f04512f953aad5b31659)
+++ src/sas/sascalc/dataloader/readers/danse_reader.py	(revision 235f514ba93b57fa63e44309f182acef0b98bb55)
@@ -166,7 +166,7 @@
                 
                 x_vals.append(qx)
-                if xmin == None or qx < xmin:
+                if xmin is None or qx < xmin:
                     xmin = qx
-                if xmax == None or qx > xmax:
+                if xmax is None or qx > xmax:
                     xmax = qx
             
@@ -181,7 +181,7 @@
                 
                 y_vals.append(qy)
-                if ymin == None or qy < ymin:
+                if ymin is None or qy < ymin:
                     ymin = qy
-                if ymax == None or qy > ymax:
+                if ymax is None or qy > ymax:
                     ymax = qy
             
Index: src/sas/sascalc/dataloader/readers/xml_reader.py
===================================================================
--- src/sas/sascalc/dataloader/readers/xml_reader.py	(revision 463e7ffce130ae386f93cd18b87a1120743e88b5)
+++ src/sas/sascalc/dataloader/readers/xml_reader.py	(revision 235f514ba93b57fa63e44309f182acef0b98bb55)
@@ -240,5 +240,5 @@
         :param name: The name of the element to be created
         """
-        if attrib == None:
+        if attrib is None:
             attrib = {}
         return etree.Element(name, attrib, nsmap)
@@ -299,5 +299,5 @@
         """
         text = str(text)
-        if attrib == None:
+        if attrib is None:
             attrib = {}
         elem = E(elementname, attrib, text)
