Use the Python port of ogr2ogr in memory

Question

I found a Python port of ogr2ogr which can be found here
This port allows me to re-project vectors from a Python script instead of having to use the command line:
import pyogr2ogr, tempfile

with fiona.open("B:/Canada-d8-100m/Canada-d8-100m.geojson", "r") as before:
    print(before.crs)
> {'init': 'epsg:3347'}

pyogr2ogr.main(["","-t_srs", "EPSG:4326", "-f", "GeoJSON", "B:/proj_test.geojson", "B:/Canada-d8-100m/Canada-d8-100m.geojson"])

with fiona.open("B:/proj_test.geojson", "r") as after:
    print(after.crs)
> {'init': 'epsg:4326'}

I would like to do the same thing as above, but I want to be able to read/write the output GeoJSON to/from memory instead of to/from the disk.
How can I do this?

ThomasG77 · Accepted Answer

You can do it purely with Fiona
import fiona
from fiona import transform

with fiona.open('B:/Canada-d8-100m/Canada-d8-100m.geojson') as input:
    # The output has the same schema
    output_schema = input.schema.copy()
    # write a new shapefile
    with fiona.open('B:/proj_test.geojson', 'w', 'GeoJSON', output_schema, crs={'init': 'epsg:4326'}) as output:
        for elem in input:
            if not elem['geometry']:
                geom = None
            else:
                geom = transform.transform_geom(
                    input.crs, 'EPSG:4326', elem['geometry'])
            output.write({
                'properties': elem['properties'],
                'geometry': geom 
            })

With Geopandas
import geopandas as gpd

geojson_input = gpd.read_file("B:/Canada-d8-100m/Canada-d8-100m.geojson")
geojson_output  = geojson_input.to_crs({'init': 'epsg:4326'}) # Had some issues here due to empty geometries...
geojson_output.to_file("B:/proj_test.geojson", driver="GeoJSON")

Use the Python port of ogr2ogr in memory

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