Dynamically add columns in datatable based on selected dropdown values

Dash Python
2

Here’s an example where selecting a value in a dropdown adds a column in the table. Let me know if it helps.

import dash
from dash.dependencies import Input, Output, State
from dash.exceptions import PreventUpdate

from dash_table import DataTable, FormatTemplate
import dash_core_components as dcc
import dash_html_components as html

app = dash.Dash(__name__)

app.layout = html.Div([
    dcc.Dropdown(
        id='dropdown',
        options=[{
            'label': 'label: ' + id,
            'value': id
        } for id in ['b', 'c', 'd', 'e', 'f']]
    ),
    DataTable(
        id='table',
        columns=[{
            'name': x,
            'id': x,
            'selectable': True
        } for x in ['a']],
        column_selectable="single",
        data=[{
            'a': 'a' + str(x),
            'b': 'b' + str(x),
            'c': 'c' + str(x),
            'd': 'd' + str(x),
            'e': 'e' + str(x),
            'f': 'f' + str(x)
        } for x in range(0,100)]
    )
])

@app.callback(
    Output('table', 'columns'),
    [Input('dropdown', 'value')],
    [State('table', 'columns')]
)
def update_columns(value, columns):
    if value is None or columns is None:
        raise PreventUpdate

    inColumns = any(c.get('id') == value for c in columns)

    if inColumns == True:
        raise PreventUpdate

    columns.append({
        'label': 'label: ' + value,
        'id': value
    })

    return columns

if __name__ == '__main__':
    app.run_server(debug=False)

dropdown_columns