I have a question about using ugettext and
ugettext_lazy for translations.
I learned that in models I should use
ugettext_lazy, while in views ugettext.
But are there any other places, where I should use
ugettext_lazy too? What about form definitions?
Are there any performance diffrences between them?
And one more thing. Sometimes, instead of
ugettext_noop is used. As documentation says,
ugettext_noop strings are only marked for translation and translated at the latest possible momment before displaying them to the user, but I'm little confused here, isn't that similar to what
ugettext_lazy do? It's still hard for me to decide, which should I use in my models and forms.
In definitions like forms or models you should use
ugettext_lazy because the code of this definitions is only executed once (mostly on django's startup);
ugettext_lazy translates the strings in a lazy fashion, which means, eg. every time you access the name of an attribute on a model the string will be newly translated-which totally makes sense because you might be looking at this model in different languages since django was started!
In views and similar function calls you can use
ugettext without problems, because everytime the view is called
ugettext will be newly executed, so you will always get the right translation fitting the request!
As Bryce pointed out in his answer, this function marks a string as extractable for translation but does return the untranslated string. This is useful for using the string in two places – translated and untranslated. See the following example:
import logging from django.http import HttpResponse from django.utils.translation import ugettext as _, ugettext_noop as _noop def view(request): msg = _noop("An error has occurred") logging.error(msg) return HttpResponse(_(msg))
An excellent use of _noop, is when you want to log a message in English for the developers, but present the translated string to a viewer. An example of this is at http://blog.bessas.me/posts/using-gettext-in-django/