[7] 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()

launch_sites = []
launch_sites.append({'label': 'All Sites', 'value': 'All Sites'})
all_launch_sites = spacex_df['Launch Site'].unique().tolist()
for launch_site in all_launch_sites:
    launch_sites.append({'label': launch_site, 'value': launch_site})

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

# 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',...)
                                html.Div([
                                    dcc.Dropdown(
                                        id = 'site-dropdown',
                                        options = launch_sites,
                                        placeholder = 'Select a Launch Site here',
                                        searchable = True ,
                                        clearable = False,
                                        value = 'All Sites'
                                        ),]),
                                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',...)
                                html.Div([
                                    dcc.RangeSlider(
                                        id = 'payload_slider',
                                        min = 0,
                                        max = 10000,
                                        step = 1000,
                                        marks = {
                                            0: {'label': '0 Kg', 'style': {'color': '#77b0b1'}},
                                            1000: {'label': '1000 Kg'},
                                            2000: {'label': '2000 Kg'},
                                            3000: {'label': '3000 Kg'},
                                            4000: {'label': '4000 Kg'},
                                            5000: {'label': '5000 Kg'},
                                            6000: {'label': '6000 Kg'},
                                            7000: {'label': '7000 Kg'},
                                            8000: {'label': '8000 Kg'},
                                            9000: {'label': '9000 Kg'},
                                            10000: {'label': '10000 Kg', 'style': {'color': '#f50'}},
                                            },
                                            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
@app.callback(
     Output(component_id = 'success-pie-chart', component_property = 'figure'),
     [Input(component_id = 'site-dropdown', component_property = 'value')]
)
def update_piegraph(site_dropdown):
    if (site_dropdown == 'All Sites' or site_dropdown == 'None'):
        data  = spacex_df[spacex_df['class'] == 1] 
        fig = px.pie(
                data,
                names = 'Launch Site',
                title = 'Total Success Launches by All Sites',
            )
    else:
        data  = spacex_df.loc[spacex_df['Launch Site'] == site_dropdown]
        fig = px.pie(
                data,
                names = 'class',
                title = 'Total Success Launches for Site ↠ '+site_dropdown,
            )
    return fig

# TASK 4:
# Add a callback function for `site-dropdown` and `payload-slider` as inputs, `success-payload-scatter-chart` as output
@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 update_scattergraph(site_dropdown,payload_slider):
    if (site_dropdown == 'All Sites' or site_dropdown == 'None'):
        low, high = payload_slider
        data  = spacex_df
        inrange = (data['Payload Mass (kg)'] > low) & (data['Payload Mass (kg)'] < high)
        fig = px.scatter(
                data[inrange], 
                x = "Payload Mass (kg)", 
                y = "class",
                title = 'Correlation Between Payload and Success for All Sites',
                color="Booster Version Category",
                size='Payload Mass (kg)',
                hover_data=['Payload Mass (kg)']
            )
    else:
        low, high = payload_slider
        data  = spacex_df.loc[spacex_df['Launch Site'] == site_dropdown]
        inrange = (data['Payload Mass (kg)'] > low) & (data['Payload Mass (kg)'] < high)
        fig = px.scatter(
                data[inrange],
                x = "Payload Mass (kg)",
                y = "class",
                title = 'Correlation Between Payload and Success for Site &#8608; '+site_dropdown,
                color="Booster Version Category",
                size='Payload Mass (kg)',
                hover_data=['Payload Mass (kg)']
            )
    return fig

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