New submission from fhdrsdg <n00rb...@gmail.com>:
Found when trying to answer this SO question: https://stackoverflow.com/questions/53171384/tkinter-function-repeats-itself-twice-when-ttk-widgets-are-engaged The ttk.OptionMenu uses radiobuttons for the dropdown menu, whereas the tkinter.OptionMenu uses commands. Both of them use `_setit` as command, presumably first used for tkinter and then copied to the ttk implementation. The `_setit` does two things: changing the associated `variable` and calling the associated callback function. This is needed for the tkinter.OptionMenu since commands don't support changing a `variable`. However, for the ttk.OptionMenu an additional reference to the variable was added to the radiobutton following this issue: https://bugs.python.org/issue25684. This was needed to group radiobuttons, but now leads to the variable being changed twice: once by the radiobutton and once through `_setit`. When tracing the variable this leads to the tracing callback being called twice on only one change of the OptionMenu. The solution is to not use `_setit` for the radiobutton command but instead just use `command=self._callback` ---------- components: Tkinter messages: 401557 nosy: fhdrsdg priority: normal severity: normal status: open title: ttk.OptionMenu radiobuttons change variable value twice type: behavior versions: Python 3.10, Python 3.11, Python 3.6, Python 3.7, Python 3.8, Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue45160> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
