CadQuery minimal sketch extrude example
The folllowing example creates a sketch in the XY plane, creates a 2x2mm rectangle in said sketch and extrudes it to a height of 0.1mm.
import cadquery as cq
# Create workplane (2d coordinate system for us to create the sketch in)
wp = cq.Workplane("XY")
# Create sketch, create rect, close sketch and extrude the resulting face
result = wp.sketch().rect(2, 2).finalize().extrude(0.1)
result # This line is just to show the result in cq-editor or jupyter