Skip CQGI assignment of unsupported parameter type (tuple)

cadquery/cqgi.py

@@ -560,9 +560,13 @@ def visit_Assign(self, node):
             if type(node.value) in astTypes:
                 self.handle_assignment(left_side.id, node.value)
             elif type(node.value) == ast.Tuple:
-                # we have a multi-value assignment
-                for n, v in zip(left_side.elts, node.value.elts):
-                    self.handle_assignment(n.id, v)
+                if isinstance(left_side, ast.Name):
+                    # skip unsupported parameter type
+                    pass
+                else:
+                    # we have a multi-value assignment
+                    for n, v in zip(left_side.elts, node.value.elts):
+                        self.handle_assignment(n.id, v)
         except:
             traceback.print_exc()
             print("Unable to handle assignment for node '%s'" % ast.dump(left_side))

doc/assy.rst

@@ -783,12 +783,14 @@ Where:
         .add(b1, loc=cq.Location((-2, 0, 0)), name="b3", color=cq.Color("red"))
     )
 
+    pnt = (0.5, 0.5, 0.5)
+
     # fix the position of b1
     assy.constrain("b1", "Fixed")
     # fix b2 center at point
-    assy.constrain("b2", "FixedPoint", (0.5, 0.5, 0.5))
+    assy.constrain("b2", "FixedPoint", pnt)
     # fix b3 vertex position at point
-    assy.constrain("b3@vertices@<X and <Y and <Z", "FixedPoint", (0.5, 0.5, 0.5))
+    assy.constrain("b3@vertices@<X and <Y and <Z", "FixedPoint", pnt)
 
     assy.solve()
     show_object(assy)