spacex_dash_app.py

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

# Read the SpaceX launch 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__)

# TASK 1: Add a Launch Site Drop-down Input Component
launch_sites = [{'label': 'All Sites', 'value': 'ALL'}] + \
               [{'label': site, 'value': site} for site in spacex_df['Launch Site'].unique()]

app.layout = html.Div(children=[
    html.H1('SpaceX Launch Records Dashboard',
            style={'textAlign': 'center', 'color': '#503D36',
                   'font-size': 40}),

    dcc.Dropdown(
        id='site-dropdown',
        options=launch_sites,
        value='ALL',
        placeholder="Select a Launch Site here",
        searchable=True
    ),
    html.Br(),

    # TASK 2: Add a pie chart
    html.Div(dcc.Graph(id='success-pie-chart')),
    html.Br(),

    html.P("Payload range (Kg):"),

    # TASK 3: Add a RangeSlider to Select Payload
    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
    html.Div(dcc.Graph(id='success-payload-scatter-chart')),
])

# TASK 2 Callback: Update pie chart based on selected site
@app.callback(
    Output(component_id='success-pie-chart', component_property='figure'),
    Input(component_id='site-dropdown', component_property='value')
)
def update_pie_chart(selected_site):
    if selected_site == 'ALL':
        fig = px.pie(spacex_df, names='Launch Site', values='class',
                     title='Total Success Launches By Site')
    else:
        filtered_df = spacex_df[spacex_df['Launch Site'] == selected_site]
        fig = px.pie(filtered_df, names='class',
                     title=f'Total Success vs Failure for site {selected_site}')
    return fig

# TASK 4 Callback: Update scatter chart based on site and payload range
@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_scatter(selected_site, payload_range):
    low, high = payload_range
    mask = (spacex_df['Payload Mass (kg)'] >= low) & (spacex_df['Payload Mass (kg)'] <= high)
    filtered_df = spacex_df[mask]

    if selected_site != 'ALL':
        filtered_df = filtered_df[filtered_df['Launch Site'] == selected_site]

    fig = px.scatter(filtered_df, x='Payload Mass (kg)', y='class',
                     color='Booster Version Category',
                     title='Correlation between Payload and Success',
                     hover_data=['Launch Site'])
    return fig

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