Geographical mapping in python using UK GeoJSON files
A couple of examples on how to plot choropleth maps for UK in python using plotly express.
To create these choropleth maps you need two things, firstly a GeoJSON file - this is a nested dictionary, which consists of propeties and coordinates of its features (i.e. the map space)
secondly you need data which you would like to map, and this needs to have an identifier to match on to the required feature in the map file.
You can find GeoJSON files online, but for UK maps the Office of National Statistics ONS contains a geographical portal which has many useful maps which can be found under the APIs drop down
A few examples:
UK Counties: https://geoportal.statistics.gov.uk/datasets/counties-december-2019-boundaries-en-bfc
UK Countries: https://geoportal.statistics.gov.uk/datasets/countries-december-2019-gb-bgc/data?geometry=-38.338%2C48.768%2C31.052%2C57.907
UK Districts: https://geoportal.statistics.gov.uk/datasets/local-authority-districts-may-2020-boundaries-uk-bgc-1
UK National parks: https://geoportal.statistics.gov.uk/datasets/national-parks-december-2019-gb-bfc
For my two examples I will do one for UK Countries (using a dummy data frame) and one for UK Districts (using real data which I found on GovUK on population statistics)
I have set these to be basic design however, you can find online easily how to use color, hover and style options.
Note ** I have used other GeoJSON files (not on ONS) and was able to use function choropleth on plotly express, however when using ONS files, I found that this would not work, suggesting to me a possible bug in the library, so instead I use choropleth_mapbox which is similar.
Start to end video on interactive mapping here: https://youtu.be/6gqHiSFD7yI