bpo-42630: Improve error reporting in Tkinter for absent default root (GH-23781)
* Tkinter functions and constructors which need a default root window
raise now RuntimeError with descriptive message instead of obscure
AttributeError or NameError if it is not created yet or cannot
be created automatically.
* Add tests for all functions which use default root window.
* Fix import in the pynche script.
diff --git a/Lib/idlelib/pyshell.py b/Lib/idlelib/pyshell.py
index c3ecdc7..abe8a85 100755
--- a/Lib/idlelib/pyshell.py
+++ b/Lib/idlelib/pyshell.py
@@ -1061,8 +1061,10 @@ def begin(self):
(sys.version, sys.platform, self.COPYRIGHT, nosub))
self.text.focus_force()
self.showprompt()
+ # User code should use separate default Tk root window
import tkinter
- tkinter._default_root = None # 03Jan04 KBK What's this?
+ tkinter._support_default_root = True
+ tkinter._default_root = None
return True
def stop_readline(self):