From: Antoine Pitrou <solipsis@pitrou.net>
Date: Fri, 4 Feb 2011 20:11:11 +0000 (+0000)
Subject: Mention that seek and tell over a TextIOWrapper can be very slow.
X-Git-Tag: v3.2rc3~55
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=eefb97cb579f8822868ce98ace820da5788e9ff7;p=python

Mention that seek and tell over a TextIOWrapper can be very slow.
---

diff --git a/Doc/library/io.rst b/Doc/library/io.rst
index a97fae0f52..26ddd8f22d 100644
--- a/Doc/library/io.rst
+++ b/Doc/library/io.rst
@@ -814,6 +814,8 @@ Text I/O over a binary storage (such as a file) is significantly slower than
 binary I/O over the same storage, because it implies conversions from
 unicode to binary data using a character codec.  This can become noticeable
 if you handle huge amounts of text data (for example very large log files).
+Also, :meth:`TextIOWrapper.tell` and :meth:`TextIOWrapper.seek` are both
+quite slow due to the reconstruction algorithm used.
 
 :class:`StringIO`, however, is a native in-memory unicode container and will
 exhibit similar speed to :class:`BytesIO`.