[Python-ideas] Gettext syntax (was Re: Allow "assigning" to ...)

[Terry Reedy]

On 2/12/2015 10:53 AM, Barry Warsaw wrote:
> On Feb 12, 2015, at 02:40 PM, Ben Finney wrote:
>
>> Gettext has been using the name ‘_’ since 1995, which was in Python's
>> infancy. The name ‘_’ is pretty obvious, I'm sure it was in use before
>> Python came along.
>
> Exactly.  All this was designed for compatibility with GNU gettext conventions
> such as in i18n'd C programs.  It was especially useful to interoperate with
> source text extraction tools.

Are you referring to then existing tools that would pull out string 
literals inside _(...) and put them in a file for translation?  I can 
see how you (all) would not want to break them.

>  We were aware of the collision with the
> interactive interpreter convenience but that wasn't deemed enough to buck
> established convention.

It leads to this

 >>> import gettext
 >>> gettext.install('foo')
 >>> _
<bound method NullTranslations.gettext of <gettext.NullTranslations 
object at 0x000000000361E978>>
 >>> _('abc')
'abc'
 >>> _
'abc'  # whoops

of
 >>> _('cat')
...
TypeError: 'str' object is not callable

Of course, one can learn to forgo the '_' convenience and test or 
experiment with explicit assignments.

 >>> s = _('cat')
 >>> s
'gato'  # for instance

I presume you decided then that this was less evil that bucking the 
external convention.

>  Using _ to imply "ignore this value" came along afterward.

Since interactive _ is usually ignored, I do not see this usage as all 
that different, except that it extends the conflict to batch made -- 
which is, of course, an important difference.



-- 
Terry Jan Reedy