Invalid geometry vs. no geometry

Question

Looking at the QGIS API Documentation:

bool QgsFeature::hasGeometry    
    Returns true if the feature has an associated geometry.

Is invalid geometry different from a feature having no associated geometry? If so, is there a tool like .hasGeometry in PyQGIS that returns whether or not the geometry is valid?

Answer 1

Yes - they are two different concepts. A null geometry means "no geometry", vs an invalid geometry which means "there's a geometry, but it violates the simple features specification in some way"

To test geometry validity:

if f.geometry().isGeosValid():
    ...