14 Jan 2022

Python: Generate WKT from Lat Long Coordinates

Recently I’ve been playing around with geometry objects in WKT format while documenting Apache Pinot’s Geospatial functions. I then wanted to figure out how to generate a WKT string from a list of lat long coordinates, which we’ll learn how to do in this blog post.

Figure 1. Python: Generate WKT from Lat Long Coordinates

We’re going to do all this using Python’s Shapely library, so let’s first install that library:

pip install shapely

Note	I learnt about the Shapely library from Davma’s StackOverflow question.

Let’s say we have a bunch of lat/long coordinates defined like this:

lat_longs = [
    (50.854457, 4.377184),
    (52.518172, 13.407759),
    (50.072651, 14.435935),
    (48.853033, 2.349553),
    (50.854457, 4.377184)
]

We’re going to create a polygon based on these coordinates using the following code:

from shapely.geometry import Polygon
polygon = Polygon(lat_longs)

And getting a WKT string is as easy as calling the wkt property:

print(polygon.wkt)

Output

POLYGON ((50.854457 4.377184, 52.518172 13.407759, 50.072651 14.435935, 48.853033 2.349553, 50.854457 4.377184))

And finally, we can plot that polygon on a map using the OpenStreetMap WKT Playground.

Figure 2. Polygon visualisation

About the author

I'm currently working on short form content at ClickHouse. I publish short 5 minute videos showing how to solve data problems on YouTube @LearnDataWithMark. I previously worked on graph analytics at Neo4j, where I also co-authored the O'Reilly Graph Algorithms Book with Amy Hodler.