[GRASS-dev] Plural form support in GRASS 7 translated messages

[Glynn Clements]

Maris Nartiss wrote:

> Currently _n() works only in C code. I hope some of Python gurus will
> clarify/implement same thing for Python parts of GRASS.

Python code uses gettext.install(), which adds several functions to
the built-in namespace:

    def install(self, unicode=False, names=None):
        import __builtin__
        __builtin__.__dict__['_'] = unicode and self.ugettext or self.gettext
        if hasattr(names, "__contains__"):
            if "gettext" in names:
                __builtin__.__dict__['gettext'] = __builtin__.__dict__['_']
            if "ngettext" in names:
                __builtin__.__dict__['ngettext'] = (unicode and self.ungettext
                                                             or self.ngettext)
            if "lgettext" in names:
                __builtin__.__dict__['lgettext'] = self.lgettext
            if "lngettext" in names:
                __builtin__.__dict__['lngettext'] = self.lngettext

If we want _n(...) to work in Python, it will need to be added
explicitly with e.g.

	import __builtin__
	__builtin__.__dict__['_n'] = __builtin__.__dict__['ngettext']

This should immediately follow the gettext.install() call, which
exists in the following files:

	scripts/v.krige/v.krige.py
	lib/python/temporal/core.py
	lib/python/script/core.py
	lib/init/prompt.py
	lib/init/grass.py
	lib/init/grass.py

Some of these use unicode=True and some don't. Setting unicode=True
binds "_" to "ugettext", which returns a unicode string. The default
setting of unicode=False binds "_" to "gettext", which returns a byte
string.

Note that passing a unicode string to a function which expects a byte
string (e.g. subprocess.Popen(), or the .write() method of streams not
explicitly opened via codecs.open()) will result in it being encoded
using the default encoding (which is usually ASCII), not the locale's
encoding.

So don't use unicode=True unless you're either prepared to explicitly
handle the encoding issues when interfacing with system functions
(command execution, I/O, etc), or you're only interacting with the
system via a library which deals with this for you (e.g. wxPython).

-- 
Glynn Clements <glynn at gclements.plus.com>