Read a CSV with two Polygons(WKT) with GDAL

Question

I am trying to read a CSV file where the geometries of neighbouring polygons are stored in couples. The file looks like this.

I usually read shapefiles in GDAL using the following syntax

GDALAllRegister();

GDALDataset       *poDS;
poDS = (GDALDataset*) GDALOpenEx("shape.shp", GDAL_OF_VECTOR, NULL, NULL, NULL );
if( poDS == NULL )
{
    printf( "Open failed.\n" );
    exit( 1 );
}

OGRLayer  *poLayer;
poLayer = poDS->GetLayerByName("shape" ); // returns the layer that refers to the name (name.shp)
cout <<"There are " <<  poLayer -> GetFeatureCount() << "features"<<endl ;
OGRFeature *poFeature;

But this of course doesn't work. The documentation found here (http://gdal.org/1.11/ogr/drv_csv.html) did not help me at all unfortunately.

I would like to know if there is a way to read this file in GDAL. I am coding in C++, but an answer in Python would be informative as well.

Answer 1

These look like Well Known Text fields.

You can load these with something like Shapely, for example.

The example from the website linked is this:

from shapely.wkt import loads
g = loads('POINT (0.0 0.0)')

Obviously yours are polygons, but it should work the same.

In C++, you will be able to load it manually, if you need. Or there are likely a few libraries, such as this one, that do it for you.

Edit: using GDAL to parse WKT directly is documented here.