I got the geometry of a feature of the shapefile, and i want to save that geometry in the postgis (in WKB formats like it happens when we import shapefiles using shp2pgsql and psql commands). How do I convert then

To get Geometry i have used OSGeo OGR library eg:

feat = layer.GetFeature(0)
geometry = feat.GetGeometryRef()

and I have got

<osgeo.ogr.Geometry; proxy of <Swig Object of type 'OGRGeometryShadow *' at 0x0096A2D8> >

so how will convert it into the WKB geometry? I am using Python for this.