commit bb70b2afe39ad4334a9f3449cddd28149bd628b6
author Serhiy Storchaka <storchaka@gmail.com> Fri Dec 25 17:04:26 2020 +0200
committer GitHub <noreply@github.com> Fri Dec 25 17:04:26 2020 +0200
tree 6d86d962cf07b543fa5d25078a24bd4b9cee54ed
parent 954a7427ba9c2d02faed32c02090caeca873aeca

bpo-15303: Support widgets with boolean value False in Tkinter (GH-23904)

Use `widget is None` instead of checking the boolean value of a widget.

Lib/tkinter/simpledialog.py

diff --git a/Lib/tkinter/simpledialog.py b/Lib/tkinter/simpledialog.py
index 638da87..d9762b1 100644
--- a/Lib/tkinter/simpledialog.py
+++ b/Lib/tkinter/simpledialog.py
@@ -99,7 +99,7 @@ def __init__(self, parent, title = None):
             title -- the dialog title
         '''
         master = parent
-        if not master:
+        if master is None:
             master = _get_default_root('create dialog window')
 
         Toplevel.__init__(self, master)
@@ -124,7 +124,7 @@ def __init__(self, parent, title = None):
 
         self.buttonbox()
 
-        if not self.initial_focus:
+        if self.initial_focus is None:
             self.initial_focus = self
 
         self.protocol("WM_DELETE_WINDOW", self.cancel)