import Part, math

focalPoint = 792.0
diameter = 2200.0
radius = diameter / 2
thickness = 3

m=App.Matrix()
m.rotateY(math.radians(-90))
# create a parabola
parabola=Part.Parabola()
# the axis of the plane the curve is lying on, this sets the symmetry axis to (0,0,1)
#parabola.Axis=App.Vector(1,0,0)
parabola.Focal = focalPoint
parabola.transform(m)
# get only the right part of the curve
edge=parabola.toShape(0,radius)
Part.show(edge)
face=edge.revolve(App.Vector(0,0,0),App.Vector(0,0,1),360)
offset=face.makeOffsetShape(-thickness,0.001)

Part.show(offset)