Dropdowns

Introduction to Data Visualization with Plotly in Python

Alex Scriven

Data Scientist

What is a dropdown?

Allows the user to select from a set of options
Updates data or layout elements

Simple dropdown example

Dropdowns in Plotly

fig = go.Figure()

for suburb in ['Ashfield', 'Lidcombe', 'Bondi Junction']:
    df = syd_houses[syd_houses.Suburb == suburb]

    fig.add_trace(
    px.bar(df, x='Year', y='Median House Price').data[0])

Dropdowns work by showing and hiding specific traces

Hiding a trace

The visible argument determines whether traces are visible (True) or not (False)
Use args to update the visible argument of different traces

args:[{'visible': [True, False, False]}]

Inside data layout

The dropdown object

# Create the dropdown
dropdown_buttons = [
  {'label': 'Ashfield', 'method': 'update',

   'args': [{'visible': [True, False, False]},
           {'title': 'Ashfield'}]},

  {'label': 'Lidcombe', 'method': 'update',

  'args': [{'visible': [False, True, False]},
          {'title': 'Lidcombe'}]},

  {'label': 'Bondi Junction', 'method': 'update',

  'args': [{'visible': [False, False, True]},
          {'title': 'Bondi Junction'}]}

]

Adding the dropdown

fig.update_layout({
  'updatemenus':[{
    'type': "dropdown",
    'x': 1.3,
    'y': 0.5,
    'showactive': True,
    'active': 0,
    'buttons': dropdown_buttons}]
})
fig.show()

Dropdown housing prices

Let's practice!

Introduction to Data Visualization with Plotly in Python