Issue #20423: fix documentation of io.StringIO's newline parameter
diff --git a/Doc/library/io.rst b/Doc/library/io.rst
index bd0ce67..3d723c0 100644
--- a/Doc/library/io.rst
+++ b/Doc/library/io.rst
@@ -844,13 +844,14 @@
Whether line buffering is enabled.
-.. class:: StringIO(initial_value='', newline=None)
+.. class:: StringIO(initial_value='', newline='\\n')
An in-memory stream for text I/O.
The initial value of the buffer (an empty string by default) can be set by
providing *initial_value*. The *newline* argument works like that of
- :class:`TextIOWrapper`. The default is to do no newline translation.
+ :class:`TextIOWrapper`. The default is to consider only ``\n`` characters
+ as end of lines and to do no newline translation.
:class:`StringIO` provides this method in addition to those from
:class:`TextIOBase` and its parents: