spacex_dash_app.py

# Import required libraries
import pandas as pd
import dash
from dash import html 
from dash import 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() -1
min_payload = spacex_df['Payload Mass (kg)'].min() +1

# 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',...)
                                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 graph', 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',...)
                                dcc.RangeSlider(id='payload-slider',
                                        min=0, max=10000, step=1000,
                                        marks={0: '0',
                                            100: '100'},
                                        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')),
                                ])

def get_df(entered_site):
    if entered_site == 'ALL':
        data=spacex_df
        data.head()
        return data
    elif entered_site == 'CCAFS LC-40':
        data=spacex_df[spacex_df['Launch Site']=='CCAFS LC-40']
        data.head()
        return data
    elif entered_site == 'VAFB SLC-4E':
        data=spacex_df[spacex_df['Launch Site']=='VAFB SLC-4E']
        data.head()
        return data
    elif entered_site == 'KSC LC-39A':
        data=spacex_df[spacex_df['Launch Site']=='KSC LC-39A']
        data.head()
        return data
    elif entered_site == 'CCAFS SLC-40':
        data = spacex_df[spacex_df['Launch Site']=='CCAFS SLC-40']
        data.head()
        return data
    else:
        print("returned null")
        return {}

# 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):
    data = get_df(entered_site)
    data.head
    if entered_site == 'ALL':
        # data=spacex_df[spacex_df['class']==1]
        fig = px.pie(data, values='class', 
            names='Launch Site', 
            title='Successes by Site')
    else:
        fig = px.pie(data, 
            names='class', 
            title='Successes by Site')
    return fig
    # return the outcomes piechart for a selected site

# 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 get_chart(entered_site, payload_slider):
    data = get_df(entered_site)
    data.head
    print(payload_slider)
    data = data[data['Payload Mass (kg)'] >= payload_slider[0]]
    data = data[data['Payload Mass (kg)'] <= payload_slider[1]]
    fig = px.scatter(data, y='class', x='Payload Mass (kg)',
    color='Booster Version Category',
        title='Scatter plot class by Booster Version Category')
    return fig
    # return the outcomes piechart for a selected site

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