Issue #12760: Add a create mode to open(). Patch by David Townshend.
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index bb1ebd9..53f5025 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -591,7 +591,8 @@
the built-in :func:`open` function.
When specified, the *mode* argument must start with one of the letters
- ``'r'``, ``'w'``, or ``'a'``, otherwise a :exc:`ValueError` is raised.
+ ``'r'``, ``'w'``, ``'x'`` or ``'a'``, otherwise a :exc:`ValueError` is
+ raised.
On Unix, when the *mode* argument starts with ``'a'``, the *O_APPEND* flag is
set on the file descriptor (which the :c:func:`fdopen` implementation already
@@ -599,6 +600,8 @@
Availability: Unix, Windows.
+ .. versionchanged:: 3.3
+ The ``'x'`` mode was added.
.. _os-fd-ops: