Define what “updating” means in docs for open (#19627).

Original patch by Lina Clark.

diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 3b3c7ddf0cf794df38f6238f7e729af8b2d13d92..dec76d3bf486a331bb91a32d31f496be4383cc68 100644 (file)
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -880,8 +880,8 @@ available.  They are listed here in alphabetical order.
    to use the system default, which is usually line buffered for tty devices and
    fully buffered for other files.  If omitted, the system default is used. [#]_
 
-   Modes ``'r+'``, ``'w+'`` and ``'a+'`` open the file for updating (note that
-   ``'w+'`` truncates the file).  Append ``'b'`` to the mode to open the file in
+   Modes ``'r+'``, ``'w+'`` and ``'a+'`` open the file for updating (reading and writing);
+   note that ``'w+'`` truncates the file.  Append ``'b'`` to the mode to open the file in
    binary mode, on systems that differentiate between binary and text files; on
    systems that don't have this distinction, adding the ``'b'`` has no effect.