title: Fields in Dash Datatable are joining
body: <p>I have the below dataframe:
  <a href="https://i.stack.imgur.com/bIG98.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bIG98.png" alt="enter image description here" /></a></p>
  <p>When I convert this to a dict and then use it to populate a dash datatable, the field driver becomes joined as below
  <a href="https://i.stack.imgur.com/SkXDv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SkXDv.png" alt="enter image description here" /></a></p>
  <p>I want the elements in the <code>driver</code> field to be comma-separated. How can I do this? My current code is below:</p>
  <pre><code>import dash
  import dash_table
  import pandas as pd
  import dash_bootstrap_components as dbc
  import dash_html_components as html
  
  ## Display Settings
  pd.set_option(&quot;max_columns&quot;,20)
  pd.set_option(&quot;max_colwidth&quot;, 50)
  pd.set_option(&quot;display.width&quot;, 2000)
  pd.set_option(&quot;max_rows&quot;, 100)
  
  import dash
  import dash_html_components as html
  import pandas as pd
  
  brand_name = ['merc', 'bmw']
  
  driver = [['driver1', 'driver2'], ['driver3', 'driver14']]
  
  df = pd.DataFrame({'brand_name':brand_name, 'driver': driver})
  print(df)
  
  df_dict = df.to_dict('records')
  
  
  app = dash.Dash(__name__)
  app.layout = dbc.Card(
      dbc.CardBody(
          [
              dash_table.DataTable(
                  id='homepage-table',
                  data=df_dict,
                  columns=[
                      {'name': 'brand_name', 'id':'brand_name'},
                      {'name': 'driver', 'id':'driver', },
  
              ],
  style_cell={'textAlign': 'left', 'padding': '5px'},
                          style_data={
                              'whiteSpace': 'normal',
                              'height': 'auto',
                              'lineHeight': '18px',
                              'width': '22px',
                              'fontSize': '14px'
                          },
                          style_header={
                              'backgroundColor': 'rgb(230, 230, 230)',
                              'fontWeight': 'bold',
                              'lineHeight': '40px',
                              'fontSize' : '18px',
                              'padding-left': '5px'
                          },
                          style_data_conditional=[
                              {'if':
                                  {
                                  'row_index': 'odd'
                                  },
                              'backgroundColor': 'rgb(248, 248, 248)'
                              },
                          ],
              )]))
  
  
  if __name__ == '__main__':
      app.run_server(debug=True)
  </code></pre>