- A new type object, 'string', is added. This is a common base type
for 'str' and 'unicode', and can be used instead of
types.StringTypes, e.g. to test whether something is "a string":
isinstance(x, string) is True for Unicode and 8-bit strings. This
is an abstract base class and cannot be instantiated directly.
diff --git a/Include/stringobject.h b/Include/stringobject.h
index 9049455..2a56ef6 100644
--- a/Include/stringobject.h
+++ b/Include/stringobject.h
@@ -39,6 +39,7 @@
char ob_sval[1];
} PyStringObject;
+extern DL_IMPORT(PyTypeObject) PyBaseString_Type;
extern DL_IMPORT(PyTypeObject) PyString_Type;
#define PyString_Check(op) PyObject_TypeCheck(op, &PyString_Type)
diff --git a/Misc/NEWS b/Misc/NEWS
index ff3fdc6..f544af4 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -6,6 +6,12 @@
Core and builtins
+- A new type object, 'string', is added. This is a common base type
+ for 'str' and 'unicode', and can be used instead of
+ types.StringTypes, e.g. to test whether something is "a string":
+ isinstance(x, string) is True for Unicode and 8-bit strings. This
+ is an abstract base class and cannot be instantiated directly.
+
- Deprecated features of xrange objects have been removed as
promised. The start, stop, and step attributes and the tolist()
method no longer exist. xrange repetition and slicing have been
diff --git a/Objects/object.c b/Objects/object.c
index 1bd8db9..b1bf2c3 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -1779,6 +1779,9 @@
if (PyType_Ready(&PyBool_Type) < 0)
Py_FatalError("Can't initialize 'bool'");
+ if (PyType_Ready(&PyString_Type) < 0)
+ Py_FatalError("Can't initialize 'str'");
+
if (PyType_Ready(&PyList_Type) < 0)
Py_FatalError("Can't initialize 'list'");
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 668668c..27b3af4 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -2855,6 +2855,60 @@
return pnew;
}
+static PyObject *
+basestring_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
+{
+ PyErr_SetString(PyExc_TypeError,
+ "The string type cannot be instantiated");
+ return NULL;
+}
+
+static char basestring_doc[] =
+"Type string cannot be instantiated; it is the base for str and unicode.";
+
+PyTypeObject PyBaseString_Type = {
+ PyObject_HEAD_INIT(&PyType_Type)
+ 0,
+ "string",
+ 0,
+ 0,
+ 0, /* tp_dealloc */
+ 0, /* tp_print */
+ 0, /* tp_getattr */
+ 0, /* tp_setattr */
+ 0, /* tp_compare */
+ 0, /* tp_repr */
+ 0, /* tp_as_number */
+ 0, /* tp_as_sequence */
+ 0, /* tp_as_mapping */
+ 0, /* tp_hash */
+ 0, /* tp_call */
+ 0, /* tp_str */
+ 0, /* tp_getattro */
+ 0, /* tp_setattro */
+ 0, /* tp_as_buffer */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
+ basestring_doc, /* tp_doc */
+ 0, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ 0, /* tp_iter */
+ 0, /* tp_iternext */
+ 0, /* tp_methods */
+ 0, /* tp_members */
+ 0, /* tp_getset */
+ &PyBaseObject_Type, /* tp_base */
+ 0, /* tp_dict */
+ 0, /* tp_descr_get */
+ 0, /* tp_descr_set */
+ 0, /* tp_dictoffset */
+ 0, /* tp_init */
+ 0, /* tp_alloc */
+ basestring_new, /* tp_new */
+ 0, /* tp_free */
+};
+
static char string_doc[] =
"str(object) -> string\n\
\n\
@@ -2893,7 +2947,7 @@
string_methods, /* tp_methods */
0, /* tp_members */
0, /* tp_getset */
- 0, /* tp_base */
+ &PyBaseString_Type, /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 5cc8455..0ac4941 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -5835,7 +5835,7 @@
unicode_methods, /* tp_methods */
0, /* tp_members */
0, /* tp_getset */
- 0, /* tp_base */
+ &PyBaseString_Type, /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
@@ -5859,6 +5859,8 @@
strcpy(unicode_default_encoding, "ascii");
for (i = 0; i < 256; i++)
unicode_latin1[i] = NULL;
+ if (PyType_Ready(&PyUnicode_Type) < 0)
+ Py_FatalError("Can't initialize 'unicode'");
}
/* Finalize the Unicode implementation */
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index d0411e2..311176e 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -1905,6 +1905,7 @@
SETBUILTIN("object", &PyBaseObject_Type);
SETBUILTIN("staticmethod", &PyStaticMethod_Type);
SETBUILTIN("str", &PyString_Type);
+ SETBUILTIN("string", &PyBaseString_Type);
SETBUILTIN("super", &PySuper_Type);
SETBUILTIN("tuple", &PyTuple_Type);
SETBUILTIN("type", &PyType_Type);