Vector.__init__ improvements

* added docstring
* fixed handling of QVector3D args (cannot list() them)
* refactor to no longer need return statements

pyqtgraph/Vector.py

@@ -12,35 +12,36 @@ class Vector(QtGui.QVector3D):
     """Extension of QVector3D which adds a few helpful methods."""
     
     def __init__(self, *args):
+        """
+        Handle additional constructions of a Vector
+
+        Parameters
+        ----------
+        args
+            Could be any of:
+             * 3 numerics
+             * 2 numerics (`0` assumed for z)
+             * Either of the previous in a list-like collection
+             * 1 QSizeF (`0` assumed for z)
+             * 1 QPointF (`0` assumed for z)
+             * Any other valid QVector3D init args.
+        """
+        init_args = args
         if len(args) == 1:
             if isinstance(args[0], QtCore.QSizeF):
-                x = float(args[0].width())
+                init_args = (float(args[0].width()), float(args[0].height()), 0)
-                y = float(args[0].height())
-                z = 0
             elif isinstance(args[0], QtCore.QPoint) or isinstance(args[0], QtCore.QPointF):
-                x = float(args[0].x())
+                init_args = (float(args[0].x()), float(args[0].y()), 0)
-                y = float(args[0].y())
+            elif hasattr(args[0], '__getitem__') and not isinstance(args[0], QtGui.QVector3D):
-                z = 0
-            elif isinstance(args[0], QtGui.QVector3D):
-                x = args[0].x()
-                y = args[0].y()
-                z = args[0].z()
-            elif hasattr(args[0], '__getitem__'):
                 vals = list(args[0])
                 if len(vals) == 2:
-                    x, y = vals
+                    vals.append(0)
-                    z = 0
+                if len(vals) != 3:
-                elif len(vals) == 3:
+                    raise Exception('Cannot init Vector with sequence of length %d' % len(args[0]))
-                    x, y, z = vals
+                init_args = vals
-                else:
-                    raise ValueError('Cannot init Vector with sequence of length %d' % len(args[0]))
         elif len(args) == 2:
-            x, y = args
+            init_args = (args[0], args[1], 0)
-            z = 0
+        QtGui.QVector3D.__init__(self, *init_args)
-        else:
-            x, y, z = args  # Could raise ValueError
-
-        QtGui.QVector3D.__init__(self, x, y, z)
 
     def __len__(self):
         return 3