Reworked the core examples to exclude contributed examples.

examples/Ex007_Using_Point_Lists.py

@@ -0,0 +1,32 @@
+import cadquery as cq
+
+# These can be modified rather than hardcoding values for each dimension.
+plate_radius = 2.0          # The radius of the plate that will be extruded
+hole_pattern_radius = 0.25  # Radius of circle where the holes will be placed
+thickness = 0.125           # The thickness of the plate that will be extruded
+
+# Make a plate with 4 holes in it at various points in a polar arrangement from
+# the center of the workplane.
+# 1.  Establishes a workplane that an object can be built on.
+# 1a. Uses the named plane orientation "front" to define the workplane, meaning
+#     that the positive Z direction is "up", and the negative Z direction
+#     is "down".
+# 2.  A 2D circle is drawn that will become though outer profile of the plate.
+r = cq.Workplane("front").circle(plate_radius)
+
+# 3. Push 4 points on the stack that will be used as the center points of the
+#    holes.
+r = r.pushPoints([(1.5, 0), (0, 1.5), (-1.5, 0), (0, -1.5)])
+
+# 4. This circle() call will operate on all four points, putting a circle at
+#    each one.
+r = r.circle(hole_pattern_radius)
+
+# 5.  All 2D geometry is extruded to the specified thickness of the plate.
+# 5a. The small hole circles are enclosed in the outer circle of the plate and
+#     so it is assumed that we want them to be cut out of the plate.  A
+#     separate cut operation is not needed.
+result = r.extrude(thickness)
+
+# Displays the result of this script
+show_object(result)