Sample code for plotly community forum: pie chart not updating on callback

samplecode.py

# import libraries 

import pandas as pd
import plotly.express as px 
import time 
import json
import urllib
import urllib.request

# import dash libraries 

import dash
import dash_core_components as dcc

# import dash bootstrap components 

import dash_bootstrap_components as dbc
import dash_html_components as html
import dash_table

from dash.dependencies import Input, Output
from dash_bootstrap_templates import load_figure_template

# read JSON file from Json at emergencias.pt by Tomahock 

url = "https://emergencias.pt/data"
response  = urllib.request.urlopen(url).read()

jsonResponse = json.loads(response.decode('utf-8'))

# Create dataframe with pandas from json response 

df = pd.json_normalize(jsonResponse['data'])

# Create new column that sums the values of men, vehicules, and planes/helicopters for each entry

df['total_meios'] = df['man'] + df['terrain']+df['aerial']

# Transform hour type to date/time format 

df['hour'] =pd.to_datetime(df.hour)

# sort values by date/time 

df.sort_values(by=['hour'])

df.to_csv("sample_data.csv")

fig_actual= px.pie(df,names='especieName',values='total_meios',color='district',
                #barmode='group', 
                template='plotly_white',
                hole=0.7,
                color_discrete_sequence=px.colors.sequential.RdBu)

# fig_actual layout changes 

fig_actual.update_layout(showlegend=False)

fig_actual.update_layout({
        'plot_bgcolor': '#282b2f',
        'paper_bgcolor': '#282b2f',
        })

fig_actual.update_layout(
    title="Recursos Alocados",
    legend_title="Tipo de Ocorrência",
    font=dict(
        color="white",
            size=12
    )
)
fig_actual.update_traces(textposition='outside', textinfo='percent+label')

# Get template for layout

load_figure_template("slate")

# define Dash app 

app = dash.Dash(__name__, external_stylesheets=[dbc.themes.SLATE],title='VOST Portugal - DASHOARD',update_title=None,
                meta_tags=[{'name': 'viewport',
                           'content': 'width=device-width, initial-scale=1.0, maximum-scale=1.2, minimum-scale=0.5,'}]
        )
# start server 

server = app.server

# app layout 

app.layout = dbc.Container(
    [
        # set update intervals for the three graphs 
        dcc.Interval(
           id='interval-component',
           interval=50*1000, # in milliseconds
           n_intervals=0
        ),
    # insert navigation bar     
    # navbar,
    html.Hr(),
    # create row
    dbc.Row(
        [
            dbc.Col(dcc.Graph(id='graph_actual',figure=fig_actual,animate=True, className="h-100"),lg=12),
            
            
        
        ], 
        
    ),
   ],
    # set fluid to true to make the layout mobile ready
    fluid=True,
)

@app.callback(
    Output('graph_actual', 'figure'),
    [Input('interval-component', "n_intervals")]

)

def UpdateFigActual(value):
    
    
    url = "https://emergencias.pt/data"
    response  = urllib.request.urlopen(url).read()

    jsonResponse = json.loads(response.decode('utf-8'))

    df_new_actual = pd.json_normalize(jsonResponse['data'])

    df_new_actual['hour'] =pd.to_datetime(df_new_actual.hour)

    # sort values by date/time 

    df_new_actual.sort_values(by=['hour'])

    df_new_actual['total_meios'] = df_new_actual['man'] + df_new_actual['terrain']+df_new_actual['aerial']

    df_now_actual=df_new_actual.tail(10)

    print(df_now_actual)

    # Plot 
    fig_actual=px.bar(df_now_actual,x='hour',y='total_meios',color='naturezaName',
                #barmode='group', 
                template='plotly_white',
                color_discrete_sequence=px.colors.sequential.RdBu)


    # fig_actual graph layout changes 

    fig_actual.update_layout({
            'plot_bgcolor': '#282b2f',
            'paper_bgcolor': '#282b2f',
            })
    
    fig_actual.update_layout(
        title="Fita do Tempo",
        xaxis_title="Fita do Tempo",
        yaxis_title="Meios Envolvidos",
        legend_title="Tipo de Ocorrência",
        font=dict(
            color="white"
        )
    )

    return fig_actual

# launch app 

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