Radio button UI and session state value not synchronised

[Michele1]

Hi all,

first time posting so sorry if I’m not doing the correct way.
I’ve seen this old post because I was experiencing something similar:

Radio button not rendering the correct selection value

I am dynamically rendering a set of radio buttons from a dictionary with Boolean values. When i change the selection from the rendered radio options then in the first instance it works as expected (updates the value in the dictionary and renders correct selected option) However, on the second time when i change the radio selection then it neither renders the correct radio option value nor it updates the value in the dictionary but on the third time it does. Now to correctly render the radio opti…

You can see the issue here in the playground: Playground • Streamlit
Basically everything works fine until I press the button and st.rerun() is triggered. After that, the value is set to the default one, but the UI stays on the previous selection:

Can you explain me why? How to eventually solve this?
Am I missing something?

Thanks,

Michele

[Goyo]

I think it is a but and I vaguely remember seeing it reported in github, but I can’t find the report right now.

The example can be fixed by just not calling rerun(), since clicking the button will rerun the app anyway. Your actual use case may require something different, though.