spacex_dash_app.py

# Import required libraries
import pandas as pd
import dash
import dash_html_components as html
import dash_core_components as dcc
from dash.dependencies import Input, Output
import plotly.express as px

# Read the airline data into pandas dataframe
spacex_df = pd.read_csv("spacex_launch_dash.csv")
max_payload = spacex_df['Payload Mass (kg)'].max()
min_payload = spacex_df['Payload Mass (kg)'].min()

# Create a dash application
app = dash.Dash(__name__)

##site_opt = [{'label': 'All Sites', 'value': 'ALL'}]
##site_opt.append([ {'label': i, 'value': i } for i in pd.unique(spacex_df['Launch Site']) ])

# Create an app layout
app.layout = html.Div(children=[html.H1('SpaceX Launch Records Dashboard',
                                        style={'textAlign': 'center', 'color': '#503D36',
                                               'font-size': 40}),
                                # TASK 1: Add a dropdown list to enable Launch Site selection
                                # The default select value is for ALL sites
                                # dcc.Dropdown(id='site-dropdown',...)
                                dcc.Dropdown(id='site-dropdown',
                                    options=[
                                    {'label': 'All Sites', 'value': 'ALL'},
                                    {'label': 'CCAFS LC-40', 'value': 'CCAFS LC-40'},
                                    {'label': 'VAFB SLC-4E', 'value': 'VAFB SLC-4E'},
                                    {'label': 'KSC LC-39A', 'value': 'KSC LC-39A'},
                                    {'label': 'CCAFS SLC-40', 'value': 'CCAFS SLC-40'}
                                ],
                                value='ALL',
                                placeholder="Select a Launch Site here",
                                searchable=True
                                ),
                                html.Br(),

                                # TASK 2: Add a pie chart to show the total successful launches count for all sites
                                # If a specific launch site was selected, show the Success vs. Failed counts for the site
                                html.Div(dcc.Graph(id='success-pie-chart')),
                                html.Br(),

                                html.P("Payload range (Kg):"),
                                # TASK 3: Add a slider to select payload range
                                dcc.RangeSlider(id='payload-slider',
                                                min=0, max=10000, step=1000,
                                                marks={0: '0',
                                                       2500:'2500',
                                                       5000:'5000',
                                                       7500:'7500',
                                                       10000:'10000'},
                                                value=[min_payload, max_payload]),
                                # TASK 4: Add a scatter chart to show the correlation between payload and launch success
                                html.Div(dcc.Graph(id='success-payload-scatter-chart')),
                                ])

# TASK 2:
# Add a callback function for `site-dropdown` as input, `success-pie-chart` as output

# Function decorator to specify function input and output
@app.callback(Output(component_id='success-pie-chart', component_property='figure'),
              Input(component_id='site-dropdown', component_property='value'))
def get_pie_chart(entered_site):
    filtered_df = spacex_df
    if entered_site == 'ALL':
        fig = px.pie(filtered_df, values='class',
        names='Launch Site',
        title='Launch Site Success Rates (All Sites)')
        return(fig)
    else:
        # return the outcomes piechart for a selected site
        site_filtered_df=filtered_df[filtered_df['Launch Site']== entered_site]
        count_df=site_filtered_df.groupby(['Launch Site','class']).size().reset_index(name='count')
        fig=px.pie(count_df,values='count',names='class',title="Total Success Launches (%s)" % entered_site)
        return(fig)

# TASK 4:
# Add a callback function for `site-dropdown` and `payload-slider` as inputs, `success-payload-scatter-chart` as
@app.callback(Output(component_id='success-payload-scatter-chart', component_property='figure'),
              [Input(component_id='site-dropdown', component_property='value'),
               Input(component_id='payload-slider', component_property='value')])
def get_scatter_chart(entered_site, entered_payload):
    #filtered_df = spacex_df[(spacex_df['Payload Mass (kg)']>entered_payload[0])&(spacex_df['Payload Mass (kg)']<entered_payload[1])]
    filtered_df = spacex_df[spacex_df['Payload Mass (kg)'].between(entered_payload[0],entered_payload[1])]
    if entered_site == 'ALL':
        fig = px.scatter(filtered_df, x='Payload Mass (kg)', y='class',
                         color='Booster Version Category',
                         title='Payload Mass vs Launch Outcome (All Sites)')
        #return(fig)
    else:
        site_filtered_df=filtered_df[filtered_df['Launch Site'] == entered_site]
        fig=px.scatter(site_filtered_df, x='Payload Mass (kg)', y='class',
                         color='Booster Version Category',
                         title='Payload Mass vs Launch Outcome (%s)' % entered_site)
    return(fig)

# Run the app
if __name__ == '__main__':
    app.run_server()