An implementation of lazy strings. Can be used in combination with gettext for the translation of web apps.
It's less beautiful than speaklater (an other implementation of lazy strings), but I wanted lazy strings that work even if a single thread interleaves the processing of many http requests (this happens with async frameworks).
postpone doesn't rely on a global state. And it doesn't use the thread.local() trick that speaklater uses either.
Example of use:
>>> from postpone import evalr, LazyString as _
>>> translations = {
"Order {item}.": "Commander {item}.",
"Take a nap": "Faire une sieste",
"Stare at the wall for %s minutes.": "Fixer le mur pendant %s minutes." ,
"a new pillow": "un nouvel oreiller"
}
>>> tasklist = [
_("Order {item}.").format(item = _("a new pillow")),
_("Take a nap") + '!',
_("Stare at the wall for %s minutes.") % 30
]
>>> evalr(tasklist, translations.get)
['Commander un nouvel oreiller.', 'Faire une sieste!', 'Fixer le mur pendant 30 minutes.']evalr walks python dictionaries, lists, tuples or sets and apply a function to all the strings wrapped inside a LazyString object.
To apply a function to the strings inside a single expression, you can use the eval method:
>>> s = _("Take a nap") + '!'
>>> s.eval(str.upper)
'TAKE A NAP!'
>>> s.eval(translations.get)
'Faire une sieste!'Or, again, the evalr function
>>> evalr(_("a new pillow").capitalize(), translations.get)
'Un nouvel oreiller'For most projects containing more than a few strings or languages, you'll probably want to use the gettext module to supply you with a translation function.
import gettext
translation = gettext.translation("myproject", "./locale", ["fr"])
translated_tasklist = evalr(tasklist, translation.ugettext)GitHub repo: https://github.com/leforestier/postpone
