IDLE.app on macOS stops when selection Help -> IDLE Help

[ronaldoussoren]

Bug report

Bug description:

To reproduce:

• open IDLE.app
• open the help menu
• select "IDLE help"

Opening IDLE using python3 -m idlelib shows the following traceback when doing this:

$ python3.12 -m idlelib                                                                                                                                                                                                                                                   
2024-01-05 11:41:38.672 Python[2197:15344359] ApplePersistenceIgnoreState: Existing state will not be touched. New state will be written to /var/folders/d3/rc5nx4v12y96knh2px3bpqsc0000gn/T/org.python.python.savedState
Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/idlelib/__main__.py", line 7, in <module>
    idlelib.pyshell.main()
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/idlelib/pyshell.py", line 1693, in main
    root.mainloop()
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/tkinter/__init__.py", line 1499, in mainloop
    self.tk.mainloop(n)
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/idlelib/macosx.py", line 213, in help_dialog
    help.show_idlehelp(root)
    ^^^^^^^^^^^^^^^^^^
AttributeError: module 'idlelib.help' has no attribute 'show_idlehelp'

CPython versions tested on:

3.10, 3.12

Operating systems tested on:

macOS

Linked PRs

• gh-113729: Fix the Help -> "IDLE Help" menu in IDLE #113731
• [3.12] gh-113729: Fix IDLE's Help -> "IDLE Help" menu bug in 3.12.1 and 3.11.7 (GH-113731) #113765
• [3.11] gh-113729: Fix IDLE's Help -> "IDLE Help" menu bug in 3.12.1 and 3.11.7 (GH-113731) #113766

[ronaldoussoren]

See also: https://discuss.python.org/t/idle-minor-preliminary-difficulties/42477/3

[ronaldoussoren]

A solution is to rename _helpwindow to show_idlehelp in idlelib.help, or to add show_idlehelp that calls _helpwindow. I tested with the latter and that fixes the problem for me.

[ronaldoussoren]

Note that this is not a macOS-specific issue, the same error should happen on other platforms, idlelib.editor also uses .help.show_idlehelp.

[terryjreedy]

Thanks for the fix. I introduced this regression on Dec 3, 2023 in #112683 while modifying 'htests' in several places. Unfortunately, there was no unittest and this was just before the 3.11.7 release on Dec 4 and the 3.12.1 release on Dec 7. As part of the reversion, I will add a new unittest that fails without the fix, along with a news item. Then merge and backport.