Exploring other map options and tools
The following are a few pointers on what you can explore further with mapping, without getting into too much detail.
You've probably thought about having custom polygons or areas to visualize as choropleth maps. What we have covered so far are standard countries only. Of course, you have the option of visualizing a custom area with arbitrary points.
There is a standard GeoJSON format for representing such information. It mainly consists of points, lines, and polygons. Points are simply locations on the map, similar to what we used for scatter map plots. Lines are groups of connected points, in a certain sequence, where the first and last points are not the same. And as you can guess, a polygon is similar to a line, but with the condition that the first and last points are the same. Note that many countries consist of more than one polygon. Most Plotly map functions support GeoJSON, and you can use it for custom map plotting.
This...