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.

It looks like you're out of luck, that style seems like an ill thought out option, because it clearly doesn't work, as you'd expect it to.
Your options are limited to a wx.CheckBox or you could look at an alternative onoffbutton.py available here:
https://discuss.wxpython.org/t/an-on-off-button-alternative-to-checkbox/36304/19

Spolier alert, I'm the author.
It has a variety of Radio type on/off buttons - get the zip file from the last post on the thread.

This is due to a bug in wxGTK. I submitted a pull request to fix this, which according to the maintainer's comments seems like it will be merged for wxWidgets 3.3.0. If you're using an older version, I don't know of any workaround unfortunately.