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Im trying to create a features array using python and python-geojson. I appended some features such as Polygon with working coordinates. However when I dump, there is no indentation in the geoJson file. It is all on one line and mapbox does not accept the data.

f

features = []
poly = Polygon([[(2.38, 57.322), (23.194, -20.28), (-120.43, 19.15), (2.38, 57.322)]])


features.append(Polygon([[(2.38, 57.322), (23.194, -20.28), (-120.43, 19.15), (2.38, 57.322)]]))
features.append(Feature(geometry=poly, properties={"country": "Spain"}))


feature_collection = FeatureCollection(features)

with open('myfile.geojson', 'w') as f:
   dump(feature_collection,f)
f.close()

Thats how the output looks. It should be indented instead of clustered like that.

{"type": "FeatureCollection", "features": [{"type": "Polygon", "coordinates": [[[2.38, 57.322], [23.194, -20.28], [-120.43, 19.15], [2.38, 57.322]]]}, {"geometry": {"type": "Polygon", "coordinates": [[[2.38, 57.322], [23.194, -20.28], [-120.43, 19.15], [2.38, 57.322]]]}, "type": "Feature", "properties": {"country": "Spain"}}]}

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2 Answers 2

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1

Add an 'indent' param to your dump() call:

with open('myfile.geojson', 'w') as f:
   dump(feature_collection, f, indent=4)

It's strange, however, that a piece of code won't accept JSON that is all on one line. It's just as much valid, legal JSON. That's a bug in that code. Using the 'indent' param is usually done just for human readability.

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1 Comment

geojson.dump doesn't seem to support indent. The important information is to use json.dump instead.
0

Backing up a bit, there are three types of GeoJSON objects:

  1. Geometry
  2. Feature
  3. FeatureCollection

A Feature includes a Geometry, and a FeatureCollection includes one or more Features. You can't directly put a Geometry inside a FeatureCollection, however, it needs to be a Feature.

In the example you've shared, your FeatureCollection includes one Feature and one Geometry (in this case, a Polygon). You'll need to convert that Polygon to a Feature before adding it to a FeatureCollection.

Not sure if you intended to have two identical polygons, but your example would need to look something like this to output valid GeoJSON:

features = []
poly1 = Polygon([[(2.38, 57.322), (23.194, -20.28), (-120.43, 19.15), (2.38, 57.322)]])
poly2 = Polygon([[(2.38, 57.322), (23.194, -20.28), (-120.43, 19.15), (2.38, 57.322)]])

features.append(Feature(geometry=poly1, properties={"country": "Spain"}))
features.append(Feature(geometry=poly2))

feature_collection = FeatureCollection(features)

with open('myfile.geojson', 'w') as f:
   dump(feature_collection,f)
f.close()

Indentation shouldn't matter here.

You can read more than you ever wanted to know about the GeoJSON spec at https://www.rfc-editor.org/rfc/rfc7946.

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2 Comments

Answer does touch the topic of formatting / indenting the output, does it? Also, in the code the big question is if dump refers to json.dump or geojson.dump which seem to have different underlying formatters.
@bluenote10 I think the actual problem the OP is having is caused by invalid GeoJSON data, rather than any indentation or formatting issues. I answered in this way to show why it is invalid, and how to fix it.

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