| msg83736 - (view) |
Author: Fan Decheng (r_mosaic) |
Date: 2009-03-18 09:20 |
| Platform: Windows Vista x64 Python version: 3.0.1 x64 When I use sys.stdin.readlines(), it correctly ends when I enter ^Z (ctrl-Z) on the console (this is the EOF on the console). However when I call sys.stdin.read(), it doesn't end when ^Z is entered. It ends when I enter the second ^Z. Repro steps: 1. Open python. 2. Type: import sys sys.stdin.read() 3. Type: Hello ^Z 4. Note the above ^Z should be followed by a Return. Result: The function call doesn't end. If I enter another ^Z, it ends. Expected result: The function call ends. |
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| msg83742 - (view) |
Author: Antoine Pitrou (pitrou) *  |
Date: 2009-03-18 10:51 |
| (cannot reproduce under Linux) |
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| msg83755 - (view) |
Author: Hirokazu Yamamoto (ocean-city) * |
Date: 2009-03-18 16:47 |
| I can reproduce this on coLinux(debian). But coLinux is running on windows, so its console behavior may not be same as native linux. (You need to use Ctrl+D on coLinux instead of Ctrl+Z) |
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| msg83756 - (view) |
Author: Hirokazu Yamamoto (ocean-city) * |
Date: 2009-03-18 16:55 |
| With following patch for investigation, (release30-maint) Index: Lib/io.py =================================================================== --- Lib/io.py (revision 70450) +++ Lib/io.py (working copy) @@ -57,6 +57,7 @@ import os import abc +import sys import codecs import _fileio # Import _thread instead of threading to reduce startup cost @@ -931,6 +932,7 @@ while True: # Read until EOF or until read() would block. chunk = self.raw.read() + print("============>", repr(chunk), file=sys.stderr) if chunk in empty_values: nodata_val = chunk break /////////////////////// I got this result. >>> sys.stdin.read() abc ^Z ============> b'abc\n' ^Z ============> b'' 'abc\n' To get empty chunk, we need to hit CTRL-Z twice. |
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| msg84145 - (view) |
Author: Fan Decheng (r_mosaic) |
Date: 2009-03-25 07:33 |
| Perhaps using just one read() is enough? I mean perhaps no loop is necessary? |
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| msg84166 - (view) |
Author: (cassava) |
Date: 2009-03-25 20:49 |
| This is happening on Arch Linux as well: Python 3.0.1 (r301:69556, Feb 22 2009, 02:43:30) [GCC 4.3.3] on linux2 I tried python2.6 and it ends with one Ctrl+D I tried python3.0.1 and it needs two Ctrl+D before it ends |
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| msg91154 - (view) |
Author: Martin (famart) |
Date: 2009-07-31 21:38 |
| Looks like python needs eof() or something for file objects, just like any other languages. Since read() is using the system call, that's the right behavior: read() blocks until EOF, and returns whatever was buffered. EOF character is consumed, but since it's a stdin, it is never closed. The next read() will again wait for normal input. The 2nd EOF mark without anything in-between will return an empty string. |
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| msg91296 - (view) |
Author: Gabriel Genellina (ggenellina) |
Date: 2009-08-05 02:13 |
| This is a duplicate of #1633941 |
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| msg139994 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2011-07-07 21:08 |
| I am still able to reproduce the problem with Python 3.2.1RC1 (64 bits) on Windows Seven, but not on Python 3.3 (alpha) compiled myself (using Visual C++ Express 2008). I don't know if something changed in Python 3.3, or it is related to how I compiled Python? I don't think that it is related to issue #12016 because Python 3.2.1RC1 contains the fix for #12016. |
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| msg139995 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2011-07-07 21:37 |
| > I don't know if something changed in Python 3.3, or ... Yes, something changed in Python 3.3. I fixed this issue "by mistake" :-) The fix is the following commit: New changeset 3c7792ec4547 by Victor Stinner in branch 'default': Issue #12175: BufferedReader.read(-1) now calls raw.readall() if available. http://hg.python.org/cpython/rev/3c7792ec4547 It is a bug in BufferedReader, a bug or an unexpected behaviour. Before this commit (e.g. in Python 3.2.0), BufferedReader.read(-1) calls raw.read() two times for this issue: the first call returns an non empty string (the string until the first ^Z), the second call returns an empty string (the string until the second ^Z). BufferedReader.read(-1) loop ends with raw.read() returns an empty string. You can workaround this issue by calling sys.stdin.buffer.raw.readall() or sys.stdin.buffer.raw.read(-1). I chose to not port my BufferedRead.read(-1) fix (call raw.readall() if available) in Python 3.2 because it changes the behaviour, and I don't want to do that in a minor release. Is anyone in favor of changing the behaviour of BufferedRead.read(-1) in a minor release (next 2.7.3 and 3.2.2)? Or can I close the issue (the bug is already fixed in Python 3.3)? |
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| msg140322 - (view) |
Author: Matt Joiner (anacrolix) |
Date: 2011-07-14 04:42 |
| I get this on Linux with ^D |
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| msg140326 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2011-07-14 10:44 |
| > I get this on Linux with ^D With which Python version? Did you try Python 3.3 (development version)? |
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| msg140561 - (view) |
Author: Matt Joiner (anacrolix) |
Date: 2011-07-18 07:10 |
| Feel like a total noob: Where do I get the latest source? I can't find any pre-release tarballs for 3.3, and the suggested py3k checkout doesn't work: $ hg clone http://hg.python.org/cpython#py3k py3k abort: unknown revision 'py3k'! |
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| msg140562 - (view) |
Author: Ned Deily (ned.deily) * |
Date: 2011-07-18 07:14 |
| See the developer's guide: http://docs.python.org/devguide/setup.html#getting-the-source-code hg clone http://hg.python.org/cpython directory_name |
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| msg140563 - (view) |
Author: Matt Joiner (anacrolix) |
Date: 2011-07-18 07:17 |
| This version is fixed for me: $ ./python Python 3.3.0a0 (default:7520f1bf0a81, Jul 18 2011, 17:12:12) [GCC 4.1.2 20070115 (SUSE Linux)] on linux2 |
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| msg140564 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2011-07-18 07:38 |
| @pitrou: Antoine, do you think that the following commit should be backported from 3.3 to 3.2? New changeset 3c7792ec4547 by Victor Stinner in branch 'default': Issue #12175: BufferedReader.read(-1) now calls raw.readall() if available. http://hg.python.org/cpython/rev/3c7792ec4547 It changes BufferedReader.read() behaviour a *little* bit. Only a little because FileIO.read(-1) calls FileIO.readall() internally for example. |
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| msg140572 - (view) |
Author: Antoine Pitrou (pitrou) * |
Date: 2011-07-18 11:32 |
| > Antoine, do you think that the following commit should be backported > from 3.3 to 3.2? No, I don't think so. |
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| msg140573 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2011-07-18 12:17 |
| > No, I don't think so. The issue is already fixed in 3.3, so you agree to not fix it in Python 3.2? |
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| msg261723 - (view) |
Author: Martin Panter (martin.panter) * |
Date: 2016-03-14 04:44 |
| Since this was apparenly only a bug in 3.2, can we close it as being out of date? |
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