How do add drop down menu for the folium map?

Question

For example, given the various months columns containing temperatures per specific region, how can I change the heatmap based on each month using drop down menu? I already have a map built using the geodataframe.explore(column = 'col_name').

Thanks!

Answer 1

If you're working in jupyterlab, this is pretty easy! You can combine a ipywidgets.Output widget with a ipywidgets.Dropdown to set up your canvas, then capture the follium map with the output. You then need to link them by adding an event handler.

import geopandas as gpd
import ipywidgets
from IPython.display import HTML, display

df = gpd.read_file(gpd.datasets.get_path("naturalearth_lowres"))

out = ipywidgets.Output(layout={'border': '1px solid black'})

w = ipywidgets.Dropdown(
    options=df.columns.values.tolist(),
    value=df.columns.values[0],
    description='Column:',
    disabled=False,
)

def on_dropdown_change(change):
    out.clear_output()
    with out:
        display(df.explore(w.value, cmap="Blues"))

w.observe(on_dropdown_change, names='value')
display(w)

with out:
    display(df.explore(df.columns[0], cmap="Blues"))

out