fix some more print statements

Doc/reference/datamodel.rst

@@ -1918,14 +1918,14 @@ correctness, implicit special method lookup may also bypass the
 
    >>> class Meta(type):
    ...    def __getattribute__(*args):
-   ...       print "Metaclass getattribute invoked"
+   ...       print("Metaclass getattribute invoked")
    ...       return type.__getattribute__(*args)
    ...
    >>> class C(object, metaclass=Meta):
    ...     def __len__(self):
    ...         return 10
    ...     def __getattribute__(*args):
-   ...         print "Class getattribute invoked"
+   ...         print("Class getattribute invoked")
    ...         return object.__getattribute__(*args)
    ...
    >>> c = C()