Raise a TypeError instead of a ValueError when too many initializers

are used in a Structure or Union constructor.

Lib/ctypes/test/test_structures.py

@@ -222,8 +222,8 @@ class StructureTestCase(unittest.TestCase):
         self.assertRaises(TypeError, POINT, 2, 3, x=4)
         self.assertRaises(TypeError, POINT, 2, 3, y=4)
 
-        # Should this raise TypeError instead?
-        self.assertRaises(ValueError, POINT, 2, 3, 4)
+        # too many initializers
+        self.assertRaises(TypeError, POINT, 2, 3, 4)
 
     def test_keyword_initializers(self):
         class POINT(Structure):
@@ -320,9 +320,9 @@ class StructureTestCase(unittest.TestCase):
         self.failUnlessEqual(cls, RuntimeError)
         if issubclass(Exception, object):
             self.failUnlessEqual(msg,
-                                 "(Phone) <type 'exceptions.ValueError'>: too many initializers")
+                                 "(Phone) <type 'exceptions.TypeError'>: too many initializers")
         else:
-            self.failUnlessEqual(msg, "(Phone) exceptions.ValueError: too many initializers")
+            self.failUnlessEqual(msg, "(Phone) exceptions.TypeError: too many initializers")
 
 
     def get_except(self, func, *args):

Misc/NEWS

@@ -366,6 +366,8 @@ Library
 
 - Issue #1831: ctypes now raises a TypeError if conflicting positional
   and named arguments are passed to a Structure or Union initializer.
+  When too many positional arguments are passed, also a TypeError is
+  raised instead of a ValueError.
 
 - Convert the internal ctypes array type cache to a WeakValueDict so
   that array types do not live longer than needed.

Modules/_ctypes/_ctypes.c

@@ -3557,7 +3557,7 @@ Struct_init(PyObject *self, PyObject *args, PyObject *kwds)
 
 		if (PyTuple_GET_SIZE(args) > PySequence_Length(fields)) {
 			Py_DECREF(fields);
-			PyErr_SetString(PyExc_ValueError,
+			PyErr_SetString(PyExc_TypeError,
 					"too many initializers");
 			return -1;
 		}