Combine part of geojson object into another in Python

Question

EDIT: I am trying to manipulate JSON files in Python. In my data some polygons have multiple related information: coordinates (LineString) and

Answer 1

example like this:

import json
data = json.loads(json_data)
features = data["features"]
point_handle_text = {
    i["properties"]["EntityHandle"]: i["properties"]["Text"]
    for i in features
    if i["geometry"]["type"] == "Point"
}
combine_features = []
for i in features:
    if i["geometry"]["type"] == "LineString":
        i["properties"]["Text"] = point_handle_text.get(i["properties"]["EntityHandle"])
        combine_features.append(i)
data["features"] = combine_features
json_data = json.dumps(data)

Answer 2

Yes, it is possible to get your result in python. It just requires storing the json data into a data structure we can work with in python and then writing an algorithm to combine features with the same entity type. I wrote up a script to do just that, along with comments. The program extracts the text property from the Point feature and places it into the properties of the LineString feature. Then, we essentially discard Point. BTW, your 'before' json data has a trailing comma that shouldn't be there. Using Python 3.7.0:

import json
import collections


def main():
    with open('before_data.json') as f:
        before_data = json.load(f)  # makes a python dict from the json file and stores in before
        features = before_data['features']  # list of features
        # loop through features, construct dictionary of entity handle mapped to point texts
        point_entities = collections.defaultdict()  # to avoid 'if key not in' pattern
        for feature in features:
            entity_handle = feature['properties']['EntityHandle']
            # only append points
            if feature['geometry']['type'] == 'Point':
                point_entities[entity_handle] = feature['properties']['Text']
        merged_features = []
        for feature in features:
            if feature['geometry']['type'] == 'LineString':
                entity_handle = feature['properties']['EntityHandle']
                text_percent = point_entities[entity_handle]
                feature['properties']['Text'] = text_percent
                merged_features.append(feature)
        # print(json.dumps(before_data, indent=4))
        result = before_data
        result['features'] = merged_features
    # compare with your expected output
    with open('after_data.json') as f:
        after_data = json.load(f)
        print(result == after_data)  # returns True
    # finally, write your result to a file
    with open('result.json', 'w') as output_file:
        json.dump(result, output_file)


if __name__ == '__main__':
    main()