Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.python > #72808
| From | Terry Reedy <tjreedy@udel.edu> |
|---|---|
| Subject | Re: Python 3.2 has some deadly infection |
| Date | 2014-06-05 22:08 -0400 |
| References | (15 earlier) <87sinju1hf.fsf@elektro.pacujo.net> <mailman.10757.1401996534.18130.python-list@python.org> <8738fjumy8.fsf@elektro.pacujo.net> <5390f997$0$29978$c3e8da3$5496439d@news.astraweb.com> <87ioof53z1.fsf@elektro.pacujo.net> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.10800.1402020549.18130.python-list@python.org> (permalink) |
On 6/5/2014 7:30 PM, Marko Rauhamaa wrote:
> Steven D'Aprano <steve+comp.lang.python@pearwood.info>:
>
>>> "Can be replaced" by who? By the Python developers? By me? By random
>>> library calls?
>>
>> By you. sys.stdout and friends are writable. Any code you call may
>> have replaced them with another file-like object, and you should
>> honour that.
>
> I can of course overwrite even sys and os and open and all. That hardly
> merits mentioning in the API documentation.
>
> What I'm afraid of is that the Python developers are reserving the right
> to remove the buffer and detach attributes from the standard streams in
> a future version.
No, not at all.
> That would be terrible.
Agreed.
> If it means some other module is allowed to commandeer the standard
> streams, that would be bad as well.
I think that, for the most part, library modules should either open a
file given a filename from outside or read from and write to open files
handed to them from outside, but not hard-code the std streams. The
module doc should say if the file (name or object) must be text or in
particular binary.
The warning is also a hint as to how to solve a problem, such as testing
a binary filter. Assume the module reads from and writes to .buffer and
has a main function. One approach, untested:
import sys, io, unittest
from mod import main
class Binstd:
def __init(self):
self.buffer = io.BytesIO
sys.stdin = Binstd()
sys.stdout = Binstd()
sys.stdin.buffer.write('test data')
sys.stdin.buffer.seek(0)
main()
out = sys.stdout.buffer.getvalue()
# test that out is as expected for the input
# seek to 0 and truncate for more tests
> Worst of all, I don't know why the caveat had to be there.
Because the streams can be replaced for a variety of good reasons, as above.
> Or is it maybe because some python command line options could cause
> buffer and detach not to be there? That would explain the caveat, but
> still would be kinda sucky.
The doc set documents the Python command line options, as well any that
are CPython specific. It is possible that some implementation could add
one to open stdxyz in binary mode. CPython does not really need that.
--
Terry Jan Reedy
Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Python 3.2 has some deadly infection Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-05-31 17:10 +0100
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-05-31 22:55 +0300
Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-01 02:26 +0000
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-01 12:43 +1000
Re: Python 3.2 has some deadly infection Tim Delaney <timothy.c.delaney@gmail.com> - 2014-06-02 08:54 +1000
Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-02 01:14 +0000
Re: Python 3.2 has some deadly infection Tim Delaney <timothy.c.delaney@gmail.com> - 2014-06-02 12:23 +1000
Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-01 19:46 -0700
Re: Python 3.2 has some deadly infection Wolfgang Maier <wolfgang.maier@biologie.uni-freiburg.de> - 2014-06-02 07:45 +0000
Re: Python 3.2 has some deadly infection Tim Delaney <timothy.c.delaney@gmail.com> - 2014-06-02 19:02 +1000
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-02 19:14 +1000
Re: Python 3.2 has some deadly infection Robin Becker <robin@reportlab.com> - 2014-06-02 12:10 +0100
Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-03 16:34 +0000
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-04 02:43 +1000
Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-02 17:34 -0400
Re: Python 3.2 has some deadly infection Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-06-03 17:16 +1200
Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-03 02:21 -0400
Re: Python 3.2 has some deadly infection Robin Becker <robin@reportlab.com> - 2014-06-03 15:18 +0100
Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-04 13:08 +0000
Re: Python 3.2 has some deadly infection Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-06-05 14:01 +1200
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 10:16 +0300
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-05 17:30 +1000
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 11:05 +0300
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-05 18:36 +1000
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 12:53 +0300
Re: Python 3.2 has some deadly infection wxjmfauth@gmail.com - 2014-06-05 05:43 -0700
Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-05 14:50 -0400
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 23:21 +0300
Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-05 18:09 -0400
Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-05 23:13 +0000
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 02:30 +0300
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 09:39 +1000
Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-05 22:08 -0400
Re: Python 3.2 has some deadly infection Ethan Furman <ethan@stoneleaf.us> - 2014-06-05 20:47 -0700
Re: Python 3.2 has some deadly infection Steven D'Aprano <steve@pearwood.info> - 2014-06-05 08:34 +0000
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 12:41 +0300
Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-05 06:37 -0700
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 17:45 +0300
Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-05 15:33 +0000
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 02:12 +1000
Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-05 09:54 -0700
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 03:36 +1000
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 19:52 +0300
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 03:28 +1000
Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-05 15:35 -0700
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 08:52 +1000
Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-05 20:11 -0700
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 13:20 +1000
Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-05 20:32 -0700
Re: Python 3.2 has some deadly infection Akira Li <4kir4.1i@gmail.com> - 2014-06-06 12:03 +0400
Re: Python 3.2 has some deadly infection Robin Becker <robin@reportlab.com> - 2014-06-05 16:37 +0100
Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-05 16:16 +0000
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 01:50 +1000
Re: Python 3.2 has some deadly infection Robin Becker <robin@reportlab.com> - 2014-06-05 17:17 +0100
Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-05 16:32 +0000
Re: Python 3.2 has some deadly infection Ethan Furman <ethan@stoneleaf.us> - 2014-06-06 07:40 -0700
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 03:14 +1000
Re: Python 3.2 has some deadly infection Ian Kelly <ian.g.kelly@gmail.com> - 2014-06-05 11:16 -0600
Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-05 14:11 -0400
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 21:30 +0300
Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-05 23:02 +0000
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 02:21 +0300
Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-06 12:15 +0000
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 16:00 +0300
Re: Python 3.2 has some deadly infection rurpy@yahoo.com - 2014-06-07 21:34 -0700
Re: Python 3.2 has some deadly infection Ethan Furman <ethan@stoneleaf.us> - 2014-06-06 06:24 -0700
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 17:10 +0300
Re: Python 3.2 has some deadly infection Michael Torrie <torriem@gmail.com> - 2014-06-06 09:02 -0600
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 18:32 +0300
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 01:50 +1000
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 20:02 +0300
Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-06 10:13 -0700
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 03:26 +1000
Re: Python 3.2 has some deadly infection wxjmfauth@gmail.com - 2014-06-06 11:03 -0700
Re: Python 3.2 has some deadly infection Denis McMahon <denismfmcmahon@gmail.com> - 2014-06-06 21:18 +0000
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 08:18 +1000
Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-06 15:57 +0000
Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-06 09:21 -0700
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 02:48 +1000
Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-06 10:04 -0700
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 03:12 +1000
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 20:11 +0300
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 03:16 +1000
Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 20:18 +0300
Re: Python 3.2 has some deadly infection Ned Batchelder <ned@nedbatchelder.com> - 2014-06-06 13:33 -0400
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 01:25 +1000
Re: Python 3.2 has some deadly infection wxjmfauth@gmail.com - 2014-06-06 08:44 -0700
Re: Python 3.2 has some deadly infection wxjmfauth@gmail.com - 2014-06-06 08:48 -0700
Re: Python 3.2 has some deadly infection Robin Becker <robin@reportlab.com> - 2014-06-06 12:56 +0100
Re: Python 3.2 has some deadly infection Akira Li <4kir4.1i@gmail.com> - 2014-06-05 06:49 +0400
Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-04 00:25 +1000
Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-03 14:22 -0400
csiph-web