This reverts r63675 based on the discussion in this thread:

 http://mail.python.org/pipermail/python-dev/2008-June/079988.html

Python 2.6 should stick with PyString_* in its codebase.  The PyBytes_* names
in the spirit of 3.0 are available via a #define only.  See the email thread.
diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py
index 0d6c5c0..25ff424 100755
--- a/Parser/asdl_c.py
+++ b/Parser/asdl_c.py
@@ -375,7 +375,7 @@
         # there's really nothing more we can do if this fails ...
         self.emit("if (tmp == NULL) goto failed;", 1)
         error = "expected some sort of %s, but got %%.400s" % name
-        format = "PyErr_Format(PyExc_TypeError, \"%s\", PyBytes_AS_STRING(tmp));"
+        format = "PyErr_Format(PyExc_TypeError, \"%s\", PyString_AS_STRING(tmp));"
         self.emit(format % error, 1, reflow=False)
         self.emit("failed:", 0)
         self.emit("Py_XDECREF(tmp);", 1)
@@ -704,7 +704,7 @@
     fnames = PyTuple_New(num_fields);
     if (!fnames) return NULL;
     for (i = 0; i < num_fields; i++) {
-        PyObject *field = PyBytes_FromString(fields[i]);
+        PyObject *field = PyString_FromString(fields[i]);
         if (!field) {
             Py_DECREF(fnames);
             return NULL;
@@ -723,7 +723,7 @@
     PyObject *s, *l = PyTuple_New(num_fields);
     if (!l) return 0;
     for(i = 0; i < num_fields; i++) {
-        s = PyBytes_FromString(attrs[i]);
+        s = PyString_FromString(attrs[i]);
         if (!s) {
             Py_DECREF(l);
             return 0;
@@ -797,7 +797,7 @@
         PyObject *s = PyObject_Repr(obj);
         if (s == NULL) return 1;
         PyErr_Format(PyExc_ValueError, "invalid integer value: %.400s",
-                     PyBytes_AS_STRING(s));
+                     PyString_AS_STRING(s));
         Py_DECREF(s);
         return 1;
     }
@@ -815,7 +815,7 @@
         PyObject *s = PyObject_Repr(obj);
         if (s == NULL) return 1;
         PyErr_Format(PyExc_ValueError, "invalid boolean value: %.400s",
-                     PyBytes_AS_STRING(s));
+                     PyString_AS_STRING(s));
         Py_DECREF(s);
         return 1;
     }
diff --git a/Parser/tokenizer.c b/Parser/tokenizer.c
index bce2bda..1d0a4aa 100644
--- a/Parser/tokenizer.c
+++ b/Parser/tokenizer.c
@@ -12,7 +12,7 @@
 
 #ifndef PGEN
 #include "unicodeobject.h"
-#include "bytesobject.h"
+#include "stringobject.h"
 #include "fileobject.h"
 #include "codecs.h"
 #include "abstract.h"
@@ -344,7 +344,7 @@
      1) NULL: need to call tok->decoding_readline to get a new line
      2) PyUnicodeObject *: decoding_feof has called tok->decoding_readline and
            stored the result in tok->decoding_buffer
-     3) PyBytesObject *: previous call to fp_readl did not have enough room
+     3) PyStringObject *: previous call to fp_readl did not have enough room
            (in the s buffer) to copy entire contents of the line read
            by tok->decoding_readline.  tok->decoding_buffer has the overflow.
            In this case, fp_readl is called in a loop (with an expanded buffer)
@@ -375,7 +375,7 @@
 			return error_ret(tok);
 	} else {
 		tok->decoding_buffer = NULL;
-		if (PyBytes_CheckExact(buf))
+		if (PyString_CheckExact(buf))
 			utf8 = buf;
 	}
 	if (utf8 == NULL) {
@@ -384,10 +384,10 @@
 		if (utf8 == NULL)
 			return error_ret(tok);
 	}
-	str = PyBytes_AsString(utf8);
-	utf8len = PyBytes_GET_SIZE(utf8);
+	str = PyString_AsString(utf8);
+	utf8len = PyString_GET_SIZE(utf8);
 	if (utf8len > size) {
-		tok->decoding_buffer = PyBytes_FromStringAndSize(str+size, utf8len-size);
+		tok->decoding_buffer = PyString_FromStringAndSize(str+size, utf8len-size);
 		if (tok->decoding_buffer == NULL) {
 			Py_DECREF(utf8);
 			return error_ret(tok);
@@ -591,7 +591,7 @@
 		utf8 = translate_into_utf8(str, tok->enc);
 		if (utf8 == NULL)
 			return error_ret(tok);
-		str = PyBytes_AsString(utf8);
+		str = PyString_AsString(utf8);
 	}
 #endif
 	for (s = str;; s++) {
@@ -624,7 +624,7 @@
 				"unknown encoding: %s", tok->enc);
 			return error_ret(tok);
 		}
-		str = PyBytes_AsString(utf8);
+		str = PyString_AsString(utf8);
 	}
 #endif
 	assert(tok->decoding_buffer == NULL);
@@ -706,11 +706,11 @@
 		return 0;
 
 	enc = ((PyFileObject *)sysstdin)->f_encoding;
-	if (enc == NULL || !PyBytes_Check(enc))
+	if (enc == NULL || !PyString_Check(enc))
 		return 0;
 	Py_INCREF(enc);
 
-	encoding = PyBytes_AsString(enc);
+	encoding = PyString_AsString(enc);
 	decoded = PyUnicode_Decode(*inp, strlen(*inp), encoding, NULL);
 	if (decoded == NULL)
 		goto error_clear;
@@ -720,9 +720,9 @@
 	if (utf8 == NULL)
 		goto error_clear;
 
-	assert(PyBytes_Check(utf8));
-	converted = new_string(PyBytes_AS_STRING(utf8),
-			       PyBytes_GET_SIZE(utf8));
+	assert(PyString_Check(utf8));
+	converted = new_string(PyString_AS_STRING(utf8),
+			       PyString_GET_SIZE(utf8));
 	Py_DECREF(utf8);
 	if (converted == NULL)
 		goto error_nomem;
@@ -1609,8 +1609,8 @@
 		/* convert source to original encondig */
 		PyObject *lineobj = dec_utf8(tok->encoding, tok->buf, len);
 		if (lineobj != NULL) {
-			int linelen = PyBytes_Size(lineobj);
-			const char *line = PyBytes_AsString(lineobj);
+			int linelen = PyString_Size(lineobj);
+			const char *line = PyString_AsString(lineobj);
 			text = PyObject_MALLOC(linelen + 1);
 			if (text != NULL && line != NULL) {
 				if (linelen)
@@ -1624,7 +1624,7 @@
 				PyObject *offsetobj = dec_utf8(tok->encoding, 
 							       tok->buf, *offset-1);
 				if (offsetobj) {
-					*offset = PyBytes_Size(offsetobj) + 1;
+					*offset = PyString_Size(offsetobj) + 1;
 					Py_DECREF(offsetobj);
 				}
 			}