Bugs item #1521491, was opened at 2006-07-12 22:04
Message generated for change (Comment added) made by gbrandl
You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1521491&group_id=5470
Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: Python Interpreter Core
Group: Python 2.5
Status: Open
Resolution: None
Priority: 5
Submitted By: Lior (rudnik_lior)
>Assigned to: Tim Peters (tim_one)
Summary: file.seek() influelce write() when opened with a+ mode
Initial Comment:
Python 2.5b1 (r25b1:47027, Jun 20 2006, 09:31:33)
Assuming documentation is correct: (from seek() help
"Note that if the file is opened for appending (mode
'a' or 'a+'), any seek() operations will be undone at
the next write"
Doing the following is __not__ undoing the seek
operation after calling this a few times (Simplified
code snippet):
from __future__ import with_statement
with open(path,'a+') as f:
f.seek(0,2) # go to end
pos = f.tell()
f.seek(0,0)
line = f.readline().strip()
f.seek(0,2) # go to end, not effective if opened
with mode a/a+ (currently bug?)
f.write("something")
Calling the above code repeatedly didnt increase the
file size beyond 166 bytes (in my code)
----------------------------------------------------------------------
>Comment By: Georg Brandl (gbrandl)
Date: 2006-07-28 18:54
Message:
Logged In: YES
user_id=849994
Perhaps you can try in on Windows, Tim...
----------------------------------------------------------------------
Comment By: Lior (rudnik_lior)
Date: 2006-07-28 13:35
Message:
Logged In: YES
user_id=1364480
This issue is on windows XP.
Wasnt tested on other versions (only 2.5b1 and b2)
I expect the code to always write at the end according to
the documentation. However if I user file seek (opend as A+)
to read from begining of the file, the write also goes to
begining of file.
Note - in the code snippet, please remove the last
f.seek(0,2) to see the problem! (it should have been in a
comment)
----------------------------------------------------------------------
Comment By: Georg Brandl (gbrandl)
Date: 2006-07-13 07:43
Message:
Logged In: YES
user_id=849994
I also cannot see any problem with the above code and can
append to a file indefinitely. What exactly are you
expecting the code to do, and what do you get? Which OS is this?
----------------------------------------------------------------------
Comment By: Neal Norwitz (nnorwitz)
Date: 2006-07-13 06:29
Message:
Logged In: YES
user_id=33168
This seems to work for me on Linux. Maybe we are testing
differently. What o/s and version are you using? Does this
work with Python 2.4? Can you attach a complete test case
that demonstrates this problem?
Thanks.
----------------------------------------------------------------------
Comment By: Lior (rudnik_lior)
Date: 2006-07-12 22:09
Message:
Logged In: YES
user_id=1364480
Re-tried the code with empty file - it doesnt grow beyond
creating and writting at position 0 so it seems the seek
does influence the write position.
----------------------------------------------------------------------
You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1521491&group_id=5470
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
