James T. Dennis <[EMAIL PROTECTED]> wrote: ... just to follow-up my own posting --- as gauche as that is:
> You'd think that using things like gettext would be easy. Superficially > it seems well documented in the Library Reference(*). However, it can > be surprisingly difficult to get the external details right. > * http://docs.python.org/lib/node738.html > Here's what I finally came up with as the simplest instructions, suitable > for an "overview of Python programming" class: > Start with the venerable "Hello, World!" program ... slightly modified > to make it ever-so-slightly more "functional:" > #!/usr/bin/env python > import sys > def hello(s="World"): > print "Hello,", s > if __name__ == "__main__": > args = sys.argv[1:] > if len(args): > for each in args: > hello(each) > else: > hello() > ... and add gettext support (and a little os.path handling on the > assumption that our message object files will not be readily > installable into the system /usr/share/locale tree): > #!/usr/bin/env python > import sys, os, gettext > _ = gettext.lgettext > mydir = os.path.realpath(os.path.dirname(sys.argv[0])) > localedir = os.path.join(mydir, "locale") > gettext.bindtextdomain('HelloPython', localedir) > gettext.textdomain('HelloPython') > def hello(s=_("World")): > print _("Hello,"), s Turns out this particular version is a Bad Idea(TM) if you ever try to import this into another script and use it after changing you os.environ['LANG'] value. I mentioned in another message awhile back that I have an aversion to using defaulted arguments other than by setting them as "None" and I hesitated this time and then thought: "Oh, it's fine in this case!" Here's my updated version of this script: ----------------------------------------------------------------------- #!/usr/bin/env python import gettext, os, sys _ = gettext.lgettext i18ndomain = 'HelloPython' mydir = os.path.realpath(os.path.dirname(sys.argv[0])) localedir = os.path.join(mydir, "locale") gettext.install(i18ndomain, localedir=None, unicode=1) gettext.bindtextdomain(i18ndomain, localedir) gettext.textdomain(i18ndomain) def hello(s=None): """Print "Hello, World" (or its equivalent in any supported language): Examples: >>> os.environ['LANG']='' >>> hello() Hello, World >>> os.environ['LANG']='es_ES' >>> hello() Hola, Mundo >>> os.environ['LANG']='fr_FR' >>> hello() Bonjour, Monde """ if s is None: s = _("World") print _("Hello,"), s def test(): import doctest doctest.testmod() if __name__ == "__main__": args = sys.argv[1:] if 'PYDOCTEST' in os.environ and os.environ['PYDOCTEST']: test() elif len(args): for each in args: hello(each) else: hello() ----------------------------------------------------------------------- ... now with doctest support. :) > if __name__ == "__main__": > args = sys.argv[1:] > if len(args): > for each in args: > hello(each) > else: > hello() > Note that I've only added five lines, the two modules to my import > line, and wrapped two strings with the conventional _() function. > This part is easy, and well-documented. > Running pygettext or GNU xgettext (-L or --language=Python) is > also easy and gives us a file like: > # SOME DESCRIPTIVE TITLE. > # Copyright (C) YEAR ORGANIZATION > # FIRST AUTHOR <[EMAIL PROTECTED]>, YEAR. > # > msgid "" > msgstr "" > "Project-Id-Version: PACKAGE VERSION\n" > "POT-Creation-Date: 2007-05-14 12:19+PDT\n" > "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" > "Last-Translator: FULL NAME <[EMAIL PROTECTED]>\n" > "Language-Team: LANGUAGE <[EMAIL PROTECTED]>\n" > "MIME-Version: 1.0\n" > "Content-Type: text/plain; charset=CHARSET\n" > "Content-Transfer-Encoding: ENCODING\n" > "Generated-By: pygettext.py 1.5\n" > #: HelloWorld.py:10 > msgid "World" > msgstr "" > #: HelloWorld.py:11 > msgid "Hello," > msgstr "" > ... I suppose I should add the appropriate magic package name, > version, author and other values to my source. Anyone remember > where those are documented? Does pygettext extract them from the > sources and insert them into the .pot? > Anyway, I minimally have to change one line thus: > "Content-Type: text/plain; charset=utf-8\n" > ... and I suppose there are other ways to do this more properly. > (Documented where?) > I did find that I could either change that in the .pot file or > in the individual .po files. However, if I failed to change it > then my translations would NOT work and would throw an exception. > (Where is the setting to force the _() function to fail gracefully > --- falling back to no-translation and NEVER raise exceptions? > I seem to recall there is one somewhere --- but I just spent all > evening reading the docs and various Google hits to get this far; so > please excuse me if it's a blur right now). > Now we just copy these templates to individual .po files and > make our LC_MESSAGES directories: > mkdir locale && mv HelloPython.pot locale > cd locale > for i in es_ES fr_FR # ... > do > cp HelloPython.pot HelloPython_$i.po > mkdir -p $i/LC_MESSAGES > done > ... and finally we can work on the translations. > We edit each of the _*.po files inserting "Hola" and "Bonjour" and > "Mundo" and "Monde" in the appropriate places. And then process > these into .mo files and move them into place as follows: > for i in *_*.po; do > i=${i#*_} > msgfmt -o ./${i%.po}/LC_MESSAGES/HelloPython.mo > done > ... in other words HelloPython_es_ES.po is written to > ./es_ES/LC_MESSAGES/HelloPython.mo, etc. > This last part was the hardest to get right. > To test this we simply run: > $HELLO_PATH/HelloPython.py > Hello, World > export LANG=es_ES > $HELLO_PATH/HelloPython.py > Hola, Mundo > export LANG=fr_FR > $HELLO_PATH/HelloPython.py > Bonjour, Monde > export LANG=zh_ZH > $HELLO_PATH/HelloPython.py > Hello, World > ... and we find that our Spanish and French translations work. (With > apologies if my translations are technically wrong). > Of course I realize this only barely scratches the surface of I18n and > L10n issues. Also I don't know, offhand, how much effort would be > required to make even this trivial example work on an MS Windows box. > It would be nice to find a document that would cover the topic in more > detail while still giving a sufficiently clear and concise set of examples > that one could follow them without getting hung up on something stupid > like: "Gee! You have to create $LANG/LC_MESSAGES/ directories and put > the .mo files thereunder; the Python won't find them under directly > under $LANG nor under LC_MESSAGES/$LANG" ... and "Gee! For reasons > I don't yet understand you need call both the .bindtextdomain() AND > the .textdomain() functions." ... and even "Hmmm ... seems that we > don't need to import locale and call local.setlocale() despite what > some examples in Google seem to suggest"(*) > * http://www.pixelbeat.org/programming/i18n.html > (So, when to you need that and when is gettext.install() really > useful?) > (I gather that the setlocale() stuff is not for simple string > translations but for things like numeric string formatting > with "%d" % ... for example). -- Jim Dennis, Starshine: Signed, Sealed, Delivered -- http://mail.python.org/mailman/listinfo/python-list
