how to convert geojson to shapely polygon?

Question

i have a geoJSON

geo = {'type': 'Polygon',
 'coordinates': [[[23.08437310100004, 53.15448536100007],
   [23.08459767900007, 53.15448536100007],
   [23.08594514600003, 53.153587050000056],
   (...)
   [23.08437310100004, 53.15448536100007]]]}

and i want to use these coordinates as an input to shapely.geometry.Polygon. The problem is that Polygon only accepts tuple values, meaning i have to convert this geojson to a polygon. When i try to input this type of data into a Polygon there's an error ValueError: A LinearRing must have at least 3 coordinate tuples

I tried this:

[tuple(l) for l in geo['coordinates']]

but this dosen't quite work since it only returns this

[([23.08437310100004, 53.15448536100007],
  [23.08459767900007, 53.15448536100007],
  (...)
  [23.08437310100004, 53.15448536100007])]

and what i need is this (i think it's a tuple)

([(23.08437310100004, 53.15448536100007),
  (23.08459767900007, 53.15448536100007),
  (...)
  (23.08437310100004, 53.15448536100007)])

is there a function for this?

bensentropy · Accepted Answer · 2022-02-16T09:56:07.867

34

A generic solution is to use the shape function. This works for all geometries not just polygons.

from shapely.geometry import shape
from shapely.geometry.polygon import Polygon

geo: dict = {'type': 'Polygon',
   'coordinates': [[[23.08437310100004, 53.15448536100007],
   [23.08459767900007, 53.15448536100007],
   [23.08594514600003, 53.153587050000056],
   [23.08437310100004, 53.15448536100007]]]}
polygon: Polygon = shape(geo)

edited Feb 16 '22 at 09:56

answered Dec 02 '21 at 12:53

bensentropy

1,293
13
17

Really good answer here! – saru Dec 04 '21 at 23:56
1

This should be the accepted answer. – José L. Patiño Feb 15 '22 at 16:52
1

it doesnt work! – Beikeni Dec 09 '22 at 16:56
any details on why its not working? – bensentropy Dec 12 '22 at 10:43

score 4 · Answer 2 · answered Aug 17 '21 at 15:40

4

Try this,

from itertools import chain


geom = {...}
polygon = Polygon(list(chain(*geom['coordinates']))

answered Aug 17 '21 at 15:40

Crash0v3rrid3

518
2
6

This method should be more accurate I think, because in other answers only first polygon is taken into account, so if a polygon has an inner ring, it will not show up. – Guven Degirmenci Jan 30 '22 at 14:45

score 2 · Answer 3 · answered Aug 17 '21 at 15:41

from shapely.geometry import Polygon
geo = {'type': 'Polygon',
 'coordinates': [[[23.08437310100004, 53.15448536100007],
   [23.08459767900007, 53.15448536100007],
   [23.08594514600003, 53.153587050000056],
   [23.08437310100004, 53.15448536100007]]]}
Polygon([tuple(l) for l in geo['coordinates'][0]])

how to convert geojson to shapely polygon?

3 Answers3