Problem of creating dynamic dash-table based on categories column

Dash Python
1

I have dataframe with few columns. I will select a column from a dropdown option, and return a dataframe, where the new dataframe will contain 2 variable from original dataframe and an additional calculated column. Then it will display as datatable.

The sample code as follows:

column_options = [dict(label=x, value=x) for x in df.columns]

#This function gets the parameter of a column , create a range based on values and assign it to a new column, and return a dataframe

def get_df(param):
dr=df[[‘column1’,param]]
cr=dr.columns[1]+’_range’
dr[cr]=pandas.cut(x=dr[dr.columns[1]], bins=range(0,100+25,25), right=False)
rt=dr[[dr[2],dr.columns[1],dr.columns[0]]]
return rt

The generated dataframe looks like as follows:

range

app.layout = html.Div(
        html.H3("Category"),

        
        html.Div(
            [
                    
                html.Div('Select Variable'),
                html.Div(dcc.Dropdown(id='my_dropdown',
                        options=column_options                                              
                        , value='column1'))
                    
                                       
            ],
            style={"width": "25%", "float": "left"},
        ),
        html.Div(
            dash_table.DataTable(
                id='datatab'),
            style={'height': 750, 'overflowY': 'scroll'},
            className='six columns'
        ),
    )

#It selects a column, passes the column
@app.callback(Output(‘datatab’, ‘rows’), [Input(‘my_dropdown’, ‘value’)])
def make_datatab(value):
r=get_df(value)
return r.to_dict(‘records’)

When I run it, it shows error:

dash.exceptions.InvalidCallbackReturnValue: 
The callback for property `rows`
of component `drugcat` returned a value
which is not JSON serializable.

In general, Dash properties can only be
dash components, strings, dictionaries, numbers, None,
or lists of those.

I have tried all possible ways.

What is the problem here? How can I resolve it?