[PyQt] Logging UTF-8 when pyqtdeployed [CLOSED]

[Barry Scott]

> On 9 Feb 2017, at 00:24, Dave Gradwell <davegradwell at yahoo.co.uk> wrote:
> 
> Just for the archives…
> To workaround this, I changed my Python Logging configuration:
> from	:	logging.basicConfig(filename=APP_LOG_PATH, level=logging.DEBU…..
> to	:	logging.basicConfig(handlers=[logging.FileHandler(filename=APP_LOG_PATH, encoding='utf-8')], level=logging.DEBU…...
> With the explicit encoding parameter, UTF-8 characters are now logged without complaint.
> 
> During investigation, I dumped os.environ in the different launching contexts and noticed:
> - When launched from PyCharm, PYTHONIOENCODING and LC_CTYPE are set to “UTF-8” and “en_US.UTF-8” respectively.
> - When invoked by launching .app/Contents/MacOS/<binary> from the Terminal.app, LANG is set to "en_GB.UTF-8”.
> - When launched by pyqtdeploy, LANG is set to "en_GB.UTF-8” (perhaps unsurprisingly, as pyqtdeploy was itself launched from Terminal.app and presumably confers its environment onto the binary it makes and launches).


> - When the app is just double-clicked, however, no environment variables are set relating to any of PYTHONIOENCODING, LC_CTYPE or LANG.   I see that __CF_USER_TEXT_ENCODING is set but I don’t think Python is particularly wowed by this.

True python does not look a __CF_USER_TEXT_ENCODING.

> 
> I checked pyqtdeploy_start.cpp.  
> locale_codec_name is "UTF-8” (which is good).  
> I also hacked-in  Py_SetStandardStreamEncoding("UTF-8", "strict”);   just before   Py_Initialize();   but this had no discernible effect.
> 
> I wonder if the lack of 'LANGUAGE', 'LC_ALL', 'LC_CTYPE' or ‘LANG’ is causing Python to fall back on a more primitive encoding…
> 
> locale.getdefaultlocale()  consistently returns None, None.

My double clicked app has LC_CTYPE=en_US.UTF-8, which is not my locale, I’m guessing that it is put there by py2app that I use
to create my apps, to get around these issues maybe.

You could add code that looks at __CF_USER_TEXT_ENCODING and do a local.setlocale early on in main.
I used to do this to make wxPython apps work well on Mac.

As yet I have not coded the conversion code for PyQt apps. But the shape of the solution is to decode the __CF_USER_TEXT_ENCODING
Into a pair of ints. Then use them in a look up table to get the country code to use in setlocale. Always using UTF-8 as the encoding.

Note that if your locale is setup then you would not have a problem with the log file. The docs for open state that the default encoding
is locale.getpreferredencoding(False) which should be utf-8 on macOS if the locale is setup.

If you do handle __CF_USER_TEXT_ENCODING be aware that some versions of macOS hex for the values and others decimal.
0x1f or 31 for example.

Of course the simplest fix is to add setlocale( ‘en_US.utf-8’ ) at the start of main() until you care about the locale in detail.

> 
> Possibly of interest:
> - https://docs.python.org/2/library/locale.html#locale.getdefaultlocale <https://docs.python.org/2/library/locale.html#locale.getdefaultlocale>
> - http://stackoverflow.com/questions/25661295/why-does-qcoreapplication-call-setlocalelc-all-by-default-on-unix-linux <http://stackoverflow.com/questions/25661295/why-does-qcoreapplication-call-setlocalelc-all-by-default-on-unix-linux>
> 
> Anyway I’m just sending this into the ether so maybe it can sit in the archives and possibly help someone else one day…
> — Dave

Barry


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