Why do I get a key not initialized error when using data_editor with key set to "feeds"

🎈 Using Streamlit
1

Summary

Why do I get a key not initialized error when using data_editor with key set to “feeds”. No example of using a key value requires initialization prior to use.

Steps to reproduce

Code snippet:

if st.session_state['SELECTED_SITE_FEEDS_DATA']:
    st.data_editor(st.session_state.save_feeds_data,use_container_width = True,num_rows = "dynamic",column_config={
        "delete?": st.column_config.CheckboxColumn(
            "Delete?",
            help="Check to Remove This Feed",
            default=False,
        )},on_change =callback(),key="feeds_data")
else:
    st.write("You must select a site before editing feeds")

If applicable, please provide the steps we should take to reproduce the error or specified behavior.

Expected behavior:

I expect the key to be created in the sessions dictionary with current data.

Actual behavior:

Error Message: AttributeError: st.session_state has no attribute “feeds_data”

Debug info

  • Streamlit version: (get it with $ streamlit version) 1.27
  • Python version: (get it with $ python --version) 3.10
  • Using Conda? PipEnv? PyEnv? Pex? Conda
  • OS version: Mac OS Monterey
  • Browser version: Latest chrome

Requirements file

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Links

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Additional information

If needed, add any other context about the problem here.

2

Hey @steelliberty,

It sounds like you haven’t initialized that session state value – check out our doc on initializing session state here.

if 'key' not in st.session_state:
    st.session_state['key'] = 'value'
3

Hey thank you Caroline - but as I read the docs that should only be necessary if i am creating my own session variable like the one in my code st.session_state[‘SELECTED_SITE_FEEDS_DATA’]. - I watched the session state video and for widgets creating a key (key=‘key’) should be sufficient to create its own entry – the code behind that would and should do just what you did – I was curious as to why that is not the case for data_editor widget – Thank you - again.

4

The key in your code is “feeds_data”`, not “feeds”. Anyway, I ran your code with both keys and got no errors.

Note that there are a few undefined things in your code, the issue may lie in the missing bits.

5

Apparently there is no solution, many people are having this problem for months and nobody took care of solving it.