Generate key stats on hover

After a recent demonstration of your work with a manager in the e-commerce company, you received a request to create a dashboard for this stakeholder. Having too many visualizations and too much text is absolutely not allowed.

Instead, they want the dashboard to be highly interactive. They have requested a scatter plot that, when hovered over, will provide some additional key stats in a text box to the right. This should change when hovering over a new point on the scatter plot.

Diese Übung ist Teil des Kurses

Building Dashboards with Dash and Plotly

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Anleitung zur Übung

Add the 'Country' column to the scatter plot's custom_data parameter below line 8 so it will appear in the hoverData property.
Create a callback below line 28 that connects the scatter_fig graph to the text_output element and will be triggered by hovering over the scatter plot.

Interaktive Übung

Versuche dich an dieser Übung, indem du diesen Beispielcode vervollständigst.

from dash import Dash, dcc, html, Input, Output, callback
import plotly.express as px
import pandas as pd
ecom_sales = pd.read_csv('/usr/local/share/datasets/ecom_sales.csv')
logo_link = 'https://assets.datacamp.com/production/repositories/5893/datasets/fdbe0accd2581a0c505dab4b29ebb66cf72a1803/e-comlogo.png'
ecom_country = ecom_sales.groupby('Country')['OrderValue'].agg(['sum', 'count']).reset_index().rename(columns={'count':'Sales Volume', 'sum':'Total Sales ($)'})

# Add the country data to the scatter plot
ecom_scatter = px.scatter(ecom_country, x='Total Sales ($)', y='Sales Volume', color='Country', width=350, height=400, ____=['____'])
ecom_scatter.update_layout({'legend':dict(orientation='h', y=-0.5,x=1, yanchor='bottom', xanchor='right'), 'margin':dict(l=20, r=20, t=25, b=0)})

app = Dash()

app.layout = [
  html.Img(src=logo_link, style={'margin':'30px 0px 0px 0px' }),
  html.H1('Sales breakdowns'),
  html.Div([
    html.H2('Sales by Country'),
    dcc.Graph(id='scatter_fig', figure=ecom_scatter)],
    style={'width':'350px', 'height':'500px', 'display':'inline-block', 
           'vertical-align':'top', 'border':'1px solid black', 'padding':'20px'}),
  html.Div([
    html.H2('Key Stats'),
    html.P(id='text_output', style={'width':'500px', 'text-align':'center'})],
    style={'width':'700px', 'height':'650px','display':'inline-block'})
]

# Trigger callback on hover
@callback(
    Output('text_output', 'children'),
    ____('scatter_fig', '____'))

def get_key_stats(hoverData):
    if not hoverData:
        return 'Hover over a country to see key stats'
    country = hoverData['points'][0]['customdata'][0]
    country_df = ecom_sales[ecom_sales['Country'] == country]
    top_major_cat = country_df.groupby('Major Category').agg('size').reset_index(name='Sales Volume').sort_values(by='Sales Volume', ascending=False).reset_index(drop=True).loc[0,'Major Category']
    top_sales_month = country_df.groupby('Year-Month')['OrderValue'].agg('sum').reset_index(name='Total Sales ($)').sort_values(by='Total Sales ($)', ascending=False).reset_index(drop=True).loc[0,'Year-Month']
    stats_list = [
      f'Key stats for : {country}', html.Br(),
      f'The most popular Major Category by sales volume was: {top_major_cat}', html.Br(),
      f'The highest sales value month was: {top_sales_month}'
    ]
    return stats_list

if __name__ == '__main__':
    app.run(debug=True)

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