Backport of several functions from Python 3.0 to 2.6 including PyUnicode_FromString, PyUnicode_Format and PyLong_From/AsSsize_t. The functions are partly required for the backport of the bytearray type and _fileio module. They should also make it easier to port C to 3.0.
First chapter of the Python 3.0 io framework back port: _fileio
The next step depends on a working bytearray type which itself depends on a backport of the nwe buffer API.
diff --git a/Include/longintrepr.h b/Include/longintrepr.h
index b1574ba..00af752 100644
--- a/Include/longintrepr.h
+++ b/Include/longintrepr.h
@@ -24,11 +24,11 @@
 typedef unsigned BASE_TWODIGITS_TYPE twodigits;
 typedef BASE_TWODIGITS_TYPE stwodigits; /* signed variant of twodigits */
 
-#define SHIFT	15
-#define BASE	((digit)1 << SHIFT)
-#define MASK	((int)(BASE - 1))
+#define PyLong_SHIFT    15
+#define PyLong_BASE     ((digit)1 << PyLong_SHIFT)
+#define PyLong_MASK     ((int)(PyLong_BASE - 1))
 
-#if SHIFT % 5 != 0
+#if PyLong_SHIFT % 5 != 0
 #error "longobject.c requires that SHIFT be divisible by 5"
 #endif
 
diff --git a/Include/longobject.h b/Include/longobject.h
index 13f2e41..379e934 100644
--- a/Include/longobject.h
+++ b/Include/longobject.h
@@ -18,14 +18,17 @@
 PyAPI_FUNC(PyObject *) PyLong_FromLong(long);
 PyAPI_FUNC(PyObject *) PyLong_FromUnsignedLong(unsigned long);
 PyAPI_FUNC(PyObject *) PyLong_FromDouble(double);
+PyAPI_FUNC(PyObject *) PyLong_FromSize_t(size_t);
+PyAPI_FUNC(PyObject *) PyLong_FromSsize_t(Py_ssize_t);
 PyAPI_FUNC(long) PyLong_AsLong(PyObject *);
 PyAPI_FUNC(unsigned long) PyLong_AsUnsignedLong(PyObject *);
 PyAPI_FUNC(unsigned long) PyLong_AsUnsignedLongMask(PyObject *);
+PyAPI_FUNC(Py_ssize_t) PyLong_AsSsize_t(PyObject *);
 
 /* For use by intobject.c only */
-PyAPI_FUNC(Py_ssize_t) _PyLong_AsSsize_t(PyObject *);
-PyAPI_FUNC(PyObject *) _PyLong_FromSize_t(size_t);
-PyAPI_FUNC(PyObject *) _PyLong_FromSsize_t(Py_ssize_t);
+#define _PyLong_AsSsize_t PyLong_AsSsize_t
+#define _PyLong_FromSize_t PyLong_FromSize_t
+#define _PyLong_FromSsize_t PyLong_FromSsize_t
 PyAPI_DATA(int) _PyLong_DigitValue[256];
 
 /* _PyLong_AsScaledDouble returns a double x and an exponent e such that
diff --git a/Include/unicodeobject.h b/Include/unicodeobject.h
index 6c33045..0c21446 100644
--- a/Include/unicodeobject.h
+++ b/Include/unicodeobject.h
@@ -183,6 +183,10 @@
 # define PyUnicode_FromObject PyUnicodeUCS2_FromObject
 # define PyUnicode_FromOrdinal PyUnicodeUCS2_FromOrdinal
 # define PyUnicode_FromUnicode PyUnicodeUCS2_FromUnicode
+# define PyUnicode_FromString PyUnicodeUCS2_FromString
+# define PyUnicode_FromStringAndSize PyUnicodeUCS2_FromStringAndSize
+# define PyUnicode_FromFormatV PyUnicodeUCS2_FromFormatV
+# define PyUnicode_FromFormat PyUnicodeUCS2_FromFormat
 # define PyUnicode_FromWideChar PyUnicodeUCS2_FromWideChar
 # define PyUnicode_GetDefaultEncoding PyUnicodeUCS2_GetDefaultEncoding
 # define PyUnicode_GetMax PyUnicodeUCS2_GetMax
@@ -265,6 +269,10 @@
 # define PyUnicode_FromObject PyUnicodeUCS4_FromObject
 # define PyUnicode_FromOrdinal PyUnicodeUCS4_FromOrdinal
 # define PyUnicode_FromUnicode PyUnicodeUCS4_FromUnicode
+# define PyUnicode_FromString PyUnicodeUCS4_FromString
+# define PyUnicode_FromStringAndSize PyUnicodeUCS4_FromStringAndSize
+# define PyUnicode_FromFormatV PyUnicodeUCS4_FromFormatV
+# define PyUnicode_FromFormat PyUnicodeUCS4_FromFormat
 # define PyUnicode_FromWideChar PyUnicodeUCS4_FromWideChar
 # define PyUnicode_GetDefaultEncoding PyUnicodeUCS4_GetDefaultEncoding
 # define PyUnicode_GetMax PyUnicodeUCS4_GetMax
@@ -442,6 +450,18 @@
     Py_ssize_t size             /* size of buffer */
     );
 
+/* Similar to PyUnicode_FromUnicode(), but u points to Latin-1 encoded bytes */
+PyAPI_FUNC(PyObject*) PyUnicode_FromStringAndSize(
+    const char *u,        /* char buffer */
+    Py_ssize_t size       /* size of buffer */
+    );
+
+/* Similar to PyUnicode_FromUnicode(), but u points to null-terminated
+   Latin-1 encoded bytes */
+PyAPI_FUNC(PyObject*) PyUnicode_FromString(
+    const char *u        /* string */
+    );
+
 /* Return a read-only pointer to the Unicode object's internal
    Py_UNICODE buffer. */
 
@@ -517,6 +537,9 @@
     register PyObject *obj 	/* Object */
     );
 
+PyAPI_FUNC(PyObject *) PyUnicode_FromFormatV(const char*, va_list);
+PyAPI_FUNC(PyObject *) PyUnicode_FromFormat(const char*, ...);
+
 /* --- wchar_t support for platforms which support it --------------------- */
 
 #ifdef HAVE_WCHAR_H