Add byteorder

Author: zklaus

Doc/library/sys.rst

@@ -38,6 +38,9 @@ always available. Unless explicitly noted otherwise, all variables are read-only
    *debug* is a boolean indicating whether the interpreter was built in
    :ref:`debug mode <debug-build>`, i.e. with the :option:`--with-pydebug` option.
 
+   *byteorder* is a string indicating the native byte order, either ``'big'`` or
+   ``'little'``.  This is the same as the :data:`byteorder` attribute.
+
    .. versionadded:: next
 
 

Lib/test/test_sys.py

@@ -744,6 +744,7 @@ def test_abi_info(self):
         self.assertEqual(len(info.__dict__), 3)
         pointer_bits = 64 if sys.maxsize > 2**32 else 32
         self.assertEqual(info.pointer_bits, pointer_bits)
+        self.assertEqual(info.byteorder, sys.byteorder)
         for attr, flag in [
             ("free_threaded", "Py_GIL_DISABLED"),
             ("debug", "Py_REF_DEBUG"),

Python/sysmodule.c

@@ -3672,6 +3672,20 @@ make_abi_info(void)
         goto error;
     }
 
+#if PY_BIG_ENDIAN
+    value = PyUnicode_FromString("big");
+#else
+    value = PyUnicode_FromString("little");
+#endif
+    if (value == NULL) {
+        goto error;
+    }
+    res = PyDict_SetItemString(abi_info, "byteorder", value);
+    if (res < 0) {
+        goto error;
+    }
+    Py_DECREF(value);
+
     ns = _PyNamespace_New(abi_info);
     Py_DECREF(abi_info);
     return ns;