This plugin is using the Leaflet plugin Sync by Jieter: https://github.com/jieter/Leaflet.Sync
The goal is to have two maps side by side. When you pan or zoom on one map, the other will move as well.
import folium
import folium.plugins
The DualMap class accepts the same arguments as the normal Map class. Except for these: 'width', 'height', 'left', 'top', 'position'.
In the following example we create a DualMap, add layer controls and then show the map. Try panning and zooming to check that both maps are synchronized.
m = folium.plugins.DualMap(location=(52.1, 5.1), zoom_start=8)
m
You can access the two submaps with attributes m1 and m2. You can add objects to each map specifically.
Here we add different tile layers to each map. This way you can see two different tile sets at the same time.
m = folium.plugins.DualMap(location=(52.1, 5.1), tiles=None, zoom_start=8)
folium.TileLayer("openstreetmap").add_to(m.m1)
folium.TileLayer("cartodbpositron").add_to(m.m2)
folium.LayerControl(collapsed=False).add_to(m)
m
Now we're going to add feature groups and markers to both maps and to each map individually. We'll color the shared icon red.
m = folium.plugins.DualMap(location=(52.1, 5.1), tiles="cartodbpositron", zoom_start=8)
fg_both = folium.FeatureGroup(name="markers_both").add_to(m)
fg_1 = folium.FeatureGroup(name="markers_1").add_to(m.m1)
fg_2 = folium.FeatureGroup(name="markers_2").add_to(m.m2)
icon_red = folium.Icon(color="red")
folium.Marker((52.0, 5.0), tooltip="both", icon=icon_red).add_to(fg_both)
folium.Marker((52.4, 5.0), tooltip="1").add_to(fg_1)
folium.Marker((52.0, 5.4), tooltip="2").add_to(fg_2)
folium.LayerControl(collapsed=False).add_to(m)
m
Finally, you can use the layout argument to change the layout to vertical:
m = folium.plugins.DualMap(layout="vertical")
m