St.session_state has no key "$$WIDGET_ID-e793ab4d3b6b8db3f8c2....."

Summary

I need help when I use st.session_state

Steps to reproduce

KeyError: ‘st.session_state has no key “$$WIDGET_ID-e793ab4d3b6b8db3f8c2d0be20452459-None”. Did you forget to initialize it? More info: Add statefulness to apps - Streamlit Docs

Traceback:

File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 548, in _run_script
    self._session_state.on_script_will_rerun(rerun_data.widget_states)File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/streamlit/runtime/state/safe_session_state.py", line 68, in on_script_will_rerun
    self._state.on_script_will_rerun(latest_widget_states)File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/streamlit/runtime/state/session_state.py", line 482, in on_script_will_rerun
    self._compact_state()File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/streamlit/runtime/state/session_state.py", line 300, in _compact_state
    self._old_state[key_or_wid] = self[key_or_wid]
                                  ~~~~^^^^^^^^^^^^File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/streamlit/runtime/state/session_state.py", line 380, in __getitem__
    raise KeyError(_missing_key_error_message(key))

Code snippet:

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Debug info

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Hey @Hangjun_Ji,

Thanks for sharing this question. Can you please share a code snippet from your app that will enable us to reproduce this error?