How to get the columns value in dropdown in dash rogram

I have a code… Here we get the Rows value by selecting the required row… But i need to get the column value by selecting the row header in the dropdown… Kindy help i have been trying this for a day…

import dash
import dash_core_components as dcc
import dash_html_components as html

import pandas as pd

df = pd.read_csv(

def generate_table(dataframe, max_rows=10):
return html.Table(
# Header
[html.Tr([html.Th(col) for col in dataframe.columns])] +

    # Body
        html.Td(dataframe.iloc[i][col]) for col in dataframe.columns
    ]) for i in range(min(len(dataframe), max_rows))]

app = dash.Dash()

app.layout = html.Div(children=[
html.H4(children=‘US Agriculture Exports (2011)’),
dcc.Dropdown(id=‘dropdown’, options=[
{‘label’: i, ‘value’: i} for i in df.state.unique()
], multi=True, placeholder=‘Filter by state…’),

dash.dependencies.Output(‘table-container’, ‘children’),
[dash.dependencies.Input(‘dropdown’, ‘value’)])
def display_table(dropdown_value):
if dropdown_value is None:
return generate_table(df)

dff = df[df.state.str.contains('|'.join(dropdown_value))]
return generate_table(dff)

app.css.append_css({“external_url”: “”})

if name == ‘main’: