"The widget with key "some_input" was created with a default value but also had its value set via the Session State API" warning in app

Using Streamlit
1

Hi guys

First time posting here.

I’m building an application where I want to be able to save the input values in a json file, so I later can reload the values. I managed to get it to work with “session_state” and given the input values “key names”

See code below:

import streamlit as st

import json

def set_values_from_json():

    file = st.session_state["file_uploader"]

    if file:

        if file.id != st.session_state["file_id"]:

            json_dir = json.loads(file.read())

            st.session_state["some_input"] = json_dir["some_value"]

            st.session_state["some_other_input"] = json_dir["some_other_value"]

            st.session_state["file_id"] = file.id

if "file_id" not in st.session_state:

    st.session_state["file_id"] = -1

st.number_input(

    "some_input",

    key="some_input",

)

st.number_input(

    "some_other_input",

    key="some_other_input",

)

file = st.file_uploader(

    "input json!", key="file_uploader", on_change=set_values_from_json

)

However, I keep getting a “The widget with key “some_input” was created with a default value but also had its value set via the Session State API.” warning the first time I load my json. Is there a way around this? Ether suppresses the warning or an alternative approach that doesn’t resolve in a warning?

Bonus question: The file_uploader “on_change” seems to trigger every time when it holds a file, not only when the file is changed. Is this a bug or intentional?

2

I also have this question, streamlit version 1.12.0, python 3.10.2 - on first upload it triggers a warning, but then never again unless streamlit itself is stopped and started. Any ideas - just suppressing the warning would be good enough for me :slight_smile:

3

I don’t see the warning using streamlit v1.12.2. The numbers are correctly updated when I load the .json file but no warnings.

4

I still have this issue in 1.13.0 , python 3.10.7 :man_shrugging:

5

I tried running your script with this json file

{
  "some_value": 0.5,
  "some_other_value": 0.6
}

But, I was unable to reproduce the warning appearing with streamlit 1.13.0. Are you just immediately uploading the file?

6

I’m also running into this warning, and I have so several times.
Using streamlit==1.41.1

Here’s a snippet I used to recreate:

radio_df = pl.DataFrame({
    'radio': ['Comercial', 'Comercial', 'RFM'],
    'day': pl.Series(['2024-01-01', '2024-07-15', '2024-12-14']).str.strptime(pl.Date, "%Y-%m-%d"),
    'values': [1, 2, 3]
})
radio_options = ['Comercial', 'RFM']

# Sidebar Filters
with st.sidebar:
    st.title(':gear: Page Settings')

    min_date = radio_df['day'].min()
    max_date = radio_df['day'].max()

    if 'date_period' not in st.session_state:
        st.session_state['date_period'] = (min_date, max_date)

    # Date Filter
    new_date_period = st.date_input(
        label=':calendar: Select the time period',
        value=(min_date, max_date),
        min_value=min_date,
        max_value=max_date,
        key='date_period'
    )

Warning:

image
image302×223 10.7 KB

7

It’s not recommended to simultaneously set a widget’s default value and manipulate its key in Session State. Instead use only the key and initialize the value through Session State.

In your example, you’ve already established a default value of the widget with st.session_state['date_period'] = (min_date, max_date) and setting key='date_period' in the widget. You don’t need to also set value=(min_date, max_date) in the widget.

import streamlit as st
import polars as pl

radio_df = pl.DataFrame({
    'radio': ['Comercial', 'Comercial', 'RFM'],
    'day': pl.Series(['2024-01-01', '2024-07-15', '2024-12-14']).str.strptime(pl.Date, "%Y-%m-%d"),
    'values': [1, 2, 3]
})
radio_options = ['Comercial', 'RFM']

# Sidebar Filters
with st.sidebar:
    st.title(':gear: Page Settings')

    min_date = radio_df['day'].min()
    max_date = radio_df['day'].max()

    if 'date_period' not in st.session_state:
        st.session_state['date_period'] = (min_date, max_date)

    # Date Filter
    new_date_period = st.date_input(
        label=':calendar: Select the time period',
        min_value=min_date,
        max_value=max_date,
        key='date_period'
    )
1 Like
8

Oh that makes sense. Thank you so much for your quick help!

2 Likes