dash-3.py

import dash
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output
import pandas as pd

df = pd.read_csv("https://allatambov.github.io/pydj/seminars/wgi-new.csv")
tab = df["fh_type"].value_counts()

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets)

app.layout = html.Div(children=[
    html.H1(children='WGI Data'),
    dcc.Dropdown(id = 'menu',
                 options = [
                 {'label' : 'Red', 'value' : '#c72418'},
                 {'label' : 'Green', 'value' : '#15bd23'}, 
                 {'label' : 'Blue', 'value' : '#5d59d9'}],
                 value = '#15bd23'),
    dcc.Graph(id = 'bar')])

@app.callback(Output('bar', 'figure'),
              [Input('menu', 'value')])

def update_graph(value):
    return {'data' : [{'x' : tab.index, 
                       'y' : tab.values, 
                       'type': 'bar', 
                       'name': 'Countries', 
                       'marker': {'color' : value}}],
            'layout': {
                'title': 'Dash Data Visualization'
            }
    }

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