diff --git a/Lib/idlelib/TreeWidget.py b/Lib/idlelib/TreeWidget.py
index d713264..7ad4002 100644
--- a/Lib/idlelib/TreeWidget.py
+++ b/Lib/idlelib/TreeWidget.py
@@ -63,7 +63,7 @@
         self.parent = parent
         self.item = item
         self.state = 'collapsed'
-        self.selected = 0
+        self.selected = False
         self.children = []
         self.x = self.y = None
         self.iconimages = {} # cache of PhotoImage instances for icons
@@ -90,7 +90,7 @@
         if self.selected:
             return
         self.deselectall()
-        self.selected = 1
+        self.selected = True
         self.canvas.delete(self.image_id)
         self.drawicon()
         self.drawtext()
@@ -98,7 +98,7 @@
     def deselect(self, event=None):
         if not self.selected:
             return
-        self.selected = 0
+        self.selected = False
         self.canvas.delete(self.image_id)
         self.drawicon()
         self.drawtext()
diff --git a/Lib/idlelib/UndoDelegator.py b/Lib/idlelib/UndoDelegator.py
index 54b0851..2452a98 100644
--- a/Lib/idlelib/UndoDelegator.py
+++ b/Lib/idlelib/UndoDelegator.py
@@ -57,7 +57,7 @@
             self.saved = self.pointer
         else:
             self.saved = -1
-        self.can_merge = 0
+        self.can_merge = False
         self.check_saved()
 
     def get_saved(self):
@@ -111,7 +111,7 @@
                 # been done, so don't execute it again
                 self.addcmd(cmd, 0)
 
-    def addcmd(self, cmd, execute=1):
+    def addcmd(self, cmd, execute=True):
         if execute:
             cmd.do(self.delegate)
         if self.undoblock != 0:
@@ -131,7 +131,7 @@
             self.pointer = self.pointer - 1
             if self.saved >= 0:
                 self.saved = self.saved - 1
-        self.can_merge = 1
+        self.can_merge = True
         self.check_saved()
 
     def undo_event(self, event):
@@ -141,7 +141,7 @@
         cmd = self.undolist[self.pointer - 1]
         cmd.undo(self.delegate)
         self.pointer = self.pointer - 1
-        self.can_merge = 0
+        self.can_merge = False
         self.check_saved()
         return "break"
 
@@ -152,7 +152,7 @@
         cmd = self.undolist[self.pointer]
         cmd.redo(self.delegate)
         self.pointer = self.pointer + 1
-        self.can_merge = 0
+        self.can_merge = False
         self.check_saved()
         return "break"
 
@@ -237,19 +237,19 @@
 
     def merge(self, cmd):
         if self.__class__ is not cmd.__class__:
-            return 0
+            return False
         if self.index2 != cmd.index1:
-            return 0
+            return False
         if self.tags != cmd.tags:
-            return 0
+            return False
         if len(cmd.chars) != 1:
-            return 0
+            return False
         if self.chars and \
            self.classify(self.chars[-1]) != self.classify(cmd.chars):
-            return 0
+            return False
         self.index2 = cmd.index2
         self.chars = self.chars + cmd.chars
-        return 1
+        return True
 
     alphanumeric = string.ascii_letters + string.digits + "_"