Convert GeoJSON to/from WKT in Python. #python #geojson #geometry

convert-geojson-to-wkt.py

import json
import geojson
from shapely.geometry import shape

o = {
   "coordinates": [[[23.314208, 37.768469], [24.039306, 37.768469], [24.039306, 38.214372], [23.314208, 38.214372], [23.314208, 37.768469]]], 
   "type": "Polygon"
}

s = json.dumps(o)

# Convert to geojson.geometry.Polygon
g1 = geojson.loads(s)

# Feed to shape() to convert to shapely.geometry.polygon.Polygon
# This will invoke its __geo_interface__ (https://gist.github.com/sgillies/2217756)
g2 = shape(g1)

# Now it's very easy to get a WKT/WKB representation
g2.wkt
g2.wkb

convert-wkt-to-geojson.py

import geojson
import shapely.wkt

s = '''POLYGON ((23.314208 37.768469, 24.039306 37.768469, 24.039306 38.214372, 23.314208 38.214372, 23.314208 37.768469))'''

# Convert to a shapely.geometry.polygon.Polygon object
g1 = shapely.wkt.loads(s)

g2 = geojson.Feature(geometry=g1, properties={})

g2.geometry

I believe convert-geojson-to-wkt.py can be simplified to:

from shapely.geometry import shape

o = {
   "coordinates": [[[23.314208, 37.768469], [24.039306, 37.768469], [24.039306, 38.214372], [23.314208, 38.214372], [23.314208, 37.768469]]], 
   "type": "Polygon"
}
geom = shape(o)

# Now it's very easy to get a WKT/WKB representation
geom.wkt
geom.wkb

👍

Actually, we just need shapely package to do everything. For convert-wkt-to-geojson.py:

import json
import shapely.wkt
import shapely.geometry

s = '''POLYGON ((23.314208 37.768469, 24.039306 37.768469, 24.039306 38.214372, 23.314208 38.214372, 23.314208 37.768469))'''

# Convert to a shapely.geometry.polygon.Polygon object
g1 = shapely.wkt.loads(s)

g2 = shapely.geometry.mapping(g1)

json.dumps(g2)

Helpful, thank you. This can be further simplified to one line. Also note that you will have a geojson string, which can then be reinterpreted to a python dictionary

from shapely.wkt import loads
from shapely.geometry import mapping
import geojson
import ast

wkt_string = '''POLYGON ((23.314208 37.768469, 24.039306 37.768469, 24.039306 38.214372, 23.314208 38.214372, 23.314208 37.768469))'''

geojson_string = geojson.dumps(mapping(loads(wkt_string)))

geojson_dict = ast.literal_eval(geojson_string)

Is there a way to read in CURVEPOLYGON as well? Some of my strings start with CURVEPOLYGON(COMPOUNDCURVE(( instead of POLYGON ((. I get the error ParseException: Unknown type: 'CURVEPOLYGON' from wkt.loads. I see it can be done using GDAL, but installation of that package is a pain.

@anottrott Instead of using ast.literal_eval(geojson_string), better use json.loads(geojson_string) when converting a JSON string to a Python dictionary.

• https://docs.python.org/3/library/json.html#json.loads

import json

from shapely.wkt import loads
from shapely.geometry import mapping
import geojson

wkt_string = "POLYGON ((23.314208 37.768469, 24.039306 37.768469, 24.039306 38.214372, 23.314208 38.214372, 23.314208 37.768469))"

geojson_string = geojson.dumps(mapping(loads(wkt_string)))

geojson_dict = json.loads(geojson_string)

print(geojson_dict)