bpo-39674: Revert "bpo-37330: open() no longer accept 'U' in file mode (GH-16959)" (GH-18767)
This reverts commit e471e72977c83664f13d041c78549140c86c92de.
The mode will be removed from Python 3.10.
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index cc48597..ca09e6f 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -1090,6 +1090,12 @@
first decoded using a platform-dependent encoding or using the specified
*encoding* if given.
+ There is an additional mode character permitted, ``'U'``, which no longer
+ has any effect, and is considered deprecated. It previously enabled
+ :term:`universal newlines` in text mode, which became the default behaviour
+ in Python 3.0. Refer to the documentation of the
+ :ref:`newline <open-newline-parameter>` parameter for further details.
+
.. note::
Python doesn't depend on the underlying operating system's notion of text
@@ -1246,6 +1252,10 @@
* The file is now non-inheritable.
+ .. deprecated-removed:: 3.4 3.10
+
+ The ``'U'`` mode.
+
.. versionchanged::
3.5
@@ -1261,10 +1271,6 @@
* On Windows, opening a console buffer may return a subclass of
:class:`io.RawIOBase` other than :class:`io.FileIO`.
- .. versionchanged:: 3.9
- The ``'U'`` mode has been removed.
-
-
.. function:: ord(c)
Given a string representing one Unicode character, return an integer