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/codecs.rst b/Doc/library/codecs.rst
index ec6a053..f071057 100644
--- a/Doc/library/codecs.rst
+++ b/Doc/library/codecs.rst
@@ -197,9 +197,6 @@
*buffering* has the same meaning as for the built-in :func:`open` function.
It defaults to -1 which means that the default buffer size will be used.
- .. versionchanged:: 3.9
- The ``'U'`` mode has been removed.
-
.. function:: EncodedFile(file, data_encoding, file_encoding=None, errors='strict')
diff --git a/Doc/library/fileinput.rst b/Doc/library/fileinput.rst
index 236f5d5..cc4039a 100644
--- a/Doc/library/fileinput.rst
+++ b/Doc/library/fileinput.rst
@@ -148,8 +148,8 @@
The sequence must be accessed in strictly sequential order; random access
and :meth:`~io.TextIOBase.readline` cannot be mixed.
- With *mode* you can specify which file mode will be passed to :func:`open`.
- It must be ``'r'`` or ``'rb'``.
+ With *mode* you can specify which file mode will be passed to :func:`open`. It
+ must be one of ``'r'``, ``'rU'``, ``'U'`` and ``'rb'``.
The *openhook*, when given, must be a function that takes two arguments,
*filename* and *mode*, and returns an accordingly opened file-like object. You
@@ -166,14 +166,15 @@
.. versionchanged:: 3.2
Can be used as a context manager.
+ .. deprecated:: 3.4
+ The ``'rU'`` and ``'U'`` modes.
+
.. deprecated:: 3.8
Support for :meth:`__getitem__` method is deprecated.
.. versionchanged:: 3.8
The keyword parameter *mode* and *openhook* are now keyword-only.
- .. versionchanged:: 3.9
- The ``'rU'`` and ``'U'`` modes have been removed.
**Optional in-place filtering:** if the keyword argument ``inplace=True`` is
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