Rotating Feature in Vector Layer using PyQGIS

Question

I am using QGIS 3.4. I am new in gis and I am trying to rotate a feature of a vector layer.

Code:

for ft in feat:
 vlayer.startEditing()
 the_geom = ft.geometry()
 pt = ft.geometry().centroid().asPoint()
 the_geom.rotate(-90, pt)
 ft.setGeometry(the_geom)
 iface.mapCanvas().refresh()
 vlayer.commitChanges()
 break

The geometry of the feature seems to change. However, I can not see any difference on the canvas.

Is there a better way to do this?

• Erik: What is a "crs layer"?
• p374: Sorry you are right, it's a vector layer.

Answer 1

Just figured it out. For anyone who would like to check the solution:

for ft in feat:
 vlayer.startEditing()
 the_geom = ft.geometry()
 pt = ft.geometry().centroid().asPoint()
 the_geom.rotate(180, pt)
 vlayer.dataProvider().changeGeometryValues({ 0 : the_geom })
 vlayer.commitChanges()
 break