DataTable dropdown option update callback output function

UPDATED CODE

import dash
from dash import Dash, dash_table, dcc, html, Input, Output, State, no_update, callback
import dash_bootstrap_components as dbc
import pandas as pd
app = dash.Dash(__name__)
# Create a sample DataFrame
df = pd.DataFrame({'TeamID': [1, 2, 3, 4],
'TeamName': ['Team 1', 'Team 2', 'Team 3', 'Team 4'],
'Finished': [1,1,0,1]})
team_select_table = dash_table.DataTable(
id='team-selection-table',
editable=True,
column_selectable="single",
row_selectable="multi",
row_deletable=False,
selected_columns=[],
page_action="native",
page_current= 0,
page_size= 100,
style_table={'minWidth': '100%'},
dropdown={},
style_header={
'backgroundColor': 'rgb(30, 30, 30)',
'color': 'white',
'fontWeight': 'bold',
'textAlign': 'center'
},
style_data={
'whiteSpace': 'normal',
'backgroundColor': 'rgb(50, 50, 50)',
'color': 'white'
},
style_data_conditional=[
{'if': {'column_id': 'TeamID'},
'width': '10%'},
{'if': {'column_id': 'TeamName'},
'width': '10%'},
],
style_cell_conditional=[
{
'if': {'column_id': c},
'textAlign': 'center'
} for c in ['TeamID', 'TeamName']
],
)
app.layout = html.Div([
team_select_table,
html.Div(id='dummy_div'),
])
@app.callback(
Output('team-selection-table', 'data'),
Output('team-selection-table', 'columns'),
Output('team-selection-table', 'dropdown'),
Output('team-selection-table', 'style_data_conditional'),
Input('dummy_div', 'children'),
prevent_initial_call=False,
background=False,
)
def load_teams(dummy):
df['Finished'] = df['Finished'].map({1: True, 0: False})  # Convert to boolean values
df_columns = [{'name': col, 'id': col} for col in df.columns]
df_data = df.to_dict(orient='records')
dropdown = {
'TeamID': {'options': [{'label': str(val), 'value': val} for val in df['TeamID'].unique()]},
'Finished': {'options': [{'label': 'Yes', 'value': True}, {'label': 'No', 'value': False}]}
}
style_data_conditional = [
{
'if': {'column_id': 'Finished'},
'presentation': 'dropdown'
}
]
return df_data, df_columns, dropdown, style_data_conditional
if __name__ == '__main__':
app.run(host="0.0.0.0", port=8020,debug=True)

Given the code above, I've been trying to update the dropdown options inside the datatable for the 'Finished' column. I cannot find an example online of someone doing this but following the references for the datatable, it should be possible. Could someone shed some light on what I'm missing? I've got more code involved but these are the primary pieces that I am having issues with.

There are multiple problems.

1 You reference dummy_div in your callback, but this element doesn't exist in the app's layout.

2 You set editable on the DataTable to False. Dropdowns are for editing so you can't have them if you've disabled editing on the datatable.

3 In your callback you do this:

dropdown = {
"Finished": {"options": [{"label": i, "value": i} for i in df["Finished"].unique()]}
}
return dropdown

If you run the app under debug Dash will tell you:
> Invalid argument dropdown.Finished.options[0].label passed into DataTable with ID "team-selection-table".
Expected string.
Was supplied type boolean.

df["Finished"] contains boolean values so convert the values to strings before you pass them as labels.

4 You don't set data and column properties on the DataTable:

# Add these
columns=[{"name": column, "id": column, "presentation": "dropdown"} for column in df.columns],
data=df.to_dict('records'),

Note the use of "presentation": "dropdown". I'm lazy in the snippet above in that I set "presentation": "dropdown" for all columns. In your case you can adjust the list comprehension to only use this for the "Finished" column.