Generating GeoJSON with Python

If you've got an GDAL/OGR dev environment (headers, libs), you could radically simplify your code by using Fiona. To read features from a shapefile, add new attributes, and write them out as GeoJSON is just a handful of lines:

import fiona
import json

features = []
crs = None
with fiona.collection("docs/data/test_uk.shp", "r") as source:
    for feat in source:
        feat['properties'].update(...) # with your attributes
        features.append(feat)
    crs = " ".join("+%s=%s" % (k,v) for k,v in source.crs.items())

my_layer = {
    "type": "FeatureCollection",
    "features": features,
    "crs": {
        "type": "link", 
        "properties": {"href": "my_layer.crs", "type": "proj4"} }}

with open("my_layer.json", "w") as f:
    f.write(json.dumps(my_layer))
with open("my_layer.crs", "w") as f:
    f.write(crs)

Happily OGR can do this for you as both ogr.Feature and ogr.Geometry objects have ExportToJson() methods. In your code;

fe.ExportToJson()

And since geojson FeatureCollection objects are simply dictionaries with a type of FeatureCollection and a features object containing a list of Feature objects.

feature_collection = {"type": "FeatureCollection",
                      "features": []
                      }

feature_collection["features"].append(fe.ExportToJson())

The CRS object in a feature collection can be one of two types:

• A named CRS (e.g. an OGC URN or an EPSG code)
• A link object with a URI and a type such as "proj4"

Depending on your data format it's quite likely that the name is going to be a pain to get from OGR. Instead if we write the projection to a file on disk which we can reference with the URI. We can grab the projection from the layer object (which has several Export functions)

spatial_reference = dl.GetSpatialRef()

with open("data.crs", "wb") as f:
    f.write(spatial_reference.ExportToProj4())

feature_collection["crs"] = {"type": "link",
                             "properties": {
                                 "href": "data.crs",
                                 "type": "proj4"
                                 }
                             }

This is the simplest and easiest one in Fiona. you can set the SRS for output GeoJSON.

import fiona
from fiona.crs import from_epsg

source= fiona.open('shp/second_shp.shp', 'r', encoding = 'utf-8')

with fiona.open('tool_shp_geojson/geojson_fiona.json','w',  driver ="GeoJSON", schema=source.schema, encoding = 'utf-8', crs=fiona.crs.from_epsg(4326)) as geojson:
     geojson.write(feat)