Fix documentation for input and output tutorial (GH-8231)

The ValueError message ends with a period.
(cherry picked from commit 9cffdbffc3b2dec18def1c3e8cfa166d01d609df)

Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>

diff --git a/Doc/tutorial/inputoutput.rst b/Doc/tutorial/inputoutput.rst
index dfa2806e1752a8b81baa406cbf2fcc5f28029eae..417c3b1319c035d4239f9a972f4e52052f98b80f 100644 (file)
--- a/Doc/tutorial/inputoutput.rst
+++ b/Doc/tutorial/inputoutput.rst
@@ -338,7 +338,7 @@ automatically fail. ::
    >>> f.read()
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
-   ValueError: I/O operation on closed file
+   ValueError: I/O operation on closed file.
 
 
 .. _tut-filemethods: