[Tutor] Tutor Digest, Vol 115, Issue 2

[Majeed Khan]

help



On Sun, Sep 1, 2013 at 12:00 PM, <tutor-request at python.org> wrote:

> Send Tutor mailing list submissions to
>         tutor at python.org
>
> To subscribe or unsubscribe via the World Wide Web, visit
>         http://mail.python.org/mailman/listinfo/tutor
> or, via email, send a message with subject or body 'help' to
>         tutor-request at python.org
>
> You can reach the person managing the list at
>         tutor-owner at python.org
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Tutor digest..."
>
>
> Today's Topics:
>
>    1. Re: myown.getfilesystemencoding() (eryksun)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sun, 1 Sep 2013 01:30:21 -0400
> From: eryksun <eryksun at gmail.com>
> To: Oscar Benjamin <oscar.j.benjamin at gmail.com>, Albert-Jan Roskam
>         <fomcl at yahoo.com>
> Cc: Python Mailing List <tutor at python.org>
> Subject: Re: [Tutor] myown.getfilesystemencoding()
> Message-ID:
>         <
> CACL+1asFy+SO2bT3UbNdP7vJTkHMuMiLmDekf9NJtMJkjHKARQ at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> On Sat, Aug 31, 2013 at 9:16 AM, Oscar Benjamin
> <oscar.j.benjamin at gmail.com> wrote:
> > Spyder has both an internal interpreter and an external interpreter.
> > One is the same interpreter process that runs the Spyder GUI. The
> > other is run in a subprocess which keeps the GUI safe but reduces your
> > ability to inspect the workspace data via the GUI. So presumable
> > Albert means the "external" interpreter here.
>
> I installed Spyder on Windows to look into this. It's using Qt
> QProcess to run the external interpreter in a child process.
> sys.stdin.isatty() confirms it's not a tty, and Process Explorer
> confirms that all 3 standard I/O handles (from msvcrt.get_osfhandle())
> are pipes.
>
> The file encoding is None for piped standard I/O, so printing unicode
> falls back to the default encoding. Normally this is ASCII in 2.x, but
> Spyder uses sitecustomize to set the default encoding based on the
> default locale. It also sets the hidden console's codepage:
>
>     if os.name == 'nt': # Windows platforms
>
>         # Setting console encoding (otherwise Python does not
>         # recognize encoding)
>         try:
>             import locale, ctypes
>             _t, _cp = locale.getdefaultlocale('LANG')
>             try:
>                 _cp = int(_cp[2:])
>                 ctypes.windll.kernel32.SetConsoleCP(_cp)
>                 ctypes.windll.kernel32.SetConsoleOutputCP(_cp)
>             except (ValueError, TypeError):
>                 # Code page number in locale is not valid
>                 pass
>         except ImportError:
>             pass
>
> http://code.google.com/p/spyderlib/source/browse/spyderlib/
> widgets/externalshell/sitecustomize.py?name=v2.2.0#74
>
> Probably this was added for a good reason, but I don't grok the point.
> Python isn't interested in the hidden console window at this stage,
> and the standard handles are all pipes. I didn't notice any difference
> with these lines commented out, running with Python 2.7.5. YMMV
>
> There's a design flaw here since sys.stdin.encoding is used by the
> parser in single-input mode. With it set to None, Unicode literals
> entered in the REPL will be incorrectly parsed if they use non-ASCII
> byte values. For example, given the input is Windows 1252, then u'?'
> will be parsed as u'\x80' (i.e. PAD, a C1 Control code).
>
> Here's an alternative to messing with the default encoding -- at least
> for the new version of Spyder that doesn't have to support 2.5. Python
> 2.6+ checks for the PYTHONIOENCODING environment variable. This
> overrides the encoding/errors values in Py_InitializeEx():
>
> http://hg.python.org/cpython/file/70274d53c1dd/Python/pythonrun.c#l265
>
> You can test setting PYTHONIOENCODING without restarting Spyder. Just
> bring up Spyder's "Internal Console" and set
> os.environ['PYTHONIOENCODING']. The change applies to new interpreters
> started from the "Interpreters" menu. Spyder could set this itself in
> the environment that gets passed to the QProcess object.
>
>
> ------------------------------
>
> Subject: Digest Footer
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>
>
> ------------------------------
>
> End of Tutor Digest, Vol 115, Issue 2
> *************************************
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/tutor/attachments/20130901/8dada48e/attachment.html>