Ubuntu – wx.RB_SINGLE makes button unable to be deselected with wxPython

According to the wxWidgets docs1, wxRB_SINGLE requires the programmer to manually handle selecting and deselecting radio buttons from the event handler for the button. However, try as I might, wxPython doesn’t let me do that. I tried both directly calling SetValue(False) on the radio button and calling the same function from the wx.EVT_RADIOBUTTON handler, but regardless the radio button stays selected and GetValue() returns True. What gives? Am I fundamentally misunderstanding something about wx.RB_SINGLE?

To clarify, my goal is to have radio buttons that — from the programmer’s perspective — function like checkboxes. I want to handle their exact behaviour myself. I don’t want any automatic grouping done by wxWidgets.

Here is the code I’ve been using to debug this:

import wx

class Example(wx.Frame):
    def __init__(self, *args, **kwargs):
        super(Example, self).__init__(*args, **kwargs)
        panel = wx.Panel(self)
        rb1 = wx.RadioButton(panel,
                                  label = 'Button 1',
                                  pos = (30, 10),
                                  style=wx.RB_SINGLE
                                  )
        rb2 = wx.RadioButton(panel,
                                  label = 'Button 2',
                                  pos = (30, 30),
                                  style=wx.RB_SINGLE
                                  )
        rb3 = wx.RadioButton(panel,
                                  label = 'Button 3',
                                  pos = (30, 50),
                                  style=wx.RB_SINGLE
                                  )
        rb2.Bind(wx.EVT_RADIOBUTTON, lambda x: rb2.SetValue(False))
        rb2.SetValue(False)


def main():
    app = wx.App()
    ex = Example(None)
    ex.Show(True)
    app.MainLoop()

if __name__ == '__main__':
    main()

For what it’s worth, I’m using Ubuntu Linux 22.04 LTS with the GTK (version 3.24.33-1ubuntu2) backend for wxWidgets (via wxPython 4.2.0) running on Python 3.10.6.