From: Georg Brandl <georg@python.org>
Date: Wed, 16 Jul 2008 23:35:54 +0000 (+0000)
Subject: #3388: add a paragraph about using "with" for file objects.
X-Git-Tag: v2.6b2~9
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a66bb0a741060b35151673dffb0d5b87307aa7e9;p=thirdparty%2FPython%2Fcpython.git

#3388: add a paragraph about using "with" for file objects.
---

diff --git a/Doc/tutorial/inputoutput.rst b/Doc/tutorial/inputoutput.rst
index fe33d12b3fa7..1b344e60b22d 100644
--- a/Doc/tutorial/inputoutput.rst
+++ b/Doc/tutorial/inputoutput.rst
@@ -348,6 +348,16 @@ attempts to use the file object will automatically fail. ::
      File "<stdin>", line 1, in ?
    ValueError: I/O operation on closed file
 
+It is good practice to use the :keyword:`with` keyword when dealing with file
+objects.  This has the advantage that the file is properly closed after its
+suite finishes, even if an exception is raised on the way.  It is also much
+shorter than writing equivalent :keyword:`try`\ -\ :keyword:`finally` blocks::
+
+    >>> with open('/tmp/workfile', 'r') as f:
+    ...     read_data = f.read()
+    >>> f.closed
+    True
+
 File objects have some additional methods, such as :meth:`isatty` and
 :meth:`truncate` which are less frequently used; consult the Library Reference
 for a complete guide to file objects.