This code creates a sketch from four segment lines forming a rectangle (given the four sets of X/Y coordinates). The segments are then assembled into a face and extruded.
import cadquery as cq xstart = 1.0 height = 4.0 width = 1.0 obj = (cq.Workplane("YZ") .sketch() .segment((xstart, 0), (xstart, height)) .segment((xstart + width, height)) .segment((xstart + width, 0)) .close() .assemble(tag="face") .finalize() .extrude(0.1) ) obj