🔎 Input format and package overview ⭐

A map is basically a set of polygons displayed on a 2 dimensional canvas. There are two problems you need to solve when building one:

Anatomy of a matplotlib chart: all the basic vocabulary you need to know to understand the documentation properly

• Where to find polygon coordinates. It can come from:
  • a shape file or a geoJson file. That's 2 different ways to store the information. The geopandas package is the best way to read those file formats with Python.
  • a python library like geopandas or basemap providing the information for common location like the US.
  • google map or open street map.


• How to plot those polygons?
  • Once you get a geodataframe thanks to the geopandas package, geoplot is your best choice to build a static map
  • If you need an interactive map from a geodataframe, plotly is a good option.
  • If you want to use google map style maps, folium is the way to go.

GeoPlot & Cartopy

GeoPlot is an extension of Cartopy and Matplotlib to create maps with minimal efforts.

Initiate a background map

Add bubble on top of a background map

Customize style and colors in bubble maps

When creating maps, there are a large number of possible projections. The article below explains how to modify them.

Change projection in maps

Folium for google maps style maps

Folium is a wrapper of the leaflet.js javascript library. It allows to make all the data wrangling with python, and benefit the power of javascript for interactive data visualization.

The map below has been created with folium... with 1 line of code only! 😍

Folium allows different types of background tiles. Here is an example with a tile called Cartodb Dark Matter:

It is also possible to add markers with associated popups on top of the map:

How to read a geoJson file with geopandas and transform it to a geodataframe.

How to read a geoJson file with geopandas and transform it to a geodataframe.

Background map with Basemap

Seaborn is another great alternative to build an area chart with python. The below examples show how to start basic, apply usual customization, and use the small multiple technique for when you have several groups to compare.

Most basic map with python and the basemap library.

Select a specific location on the map.

Customize color and features of shapes.

List of available boundaries.

Change projection.

Use a background tile.