python - ugettext and ugettext_lazy

Question

Could you explain what principal difference between ugettext and ugettext_lazy?

When I'm trying to

return HttpResponse(ugettext_lazy("Hello"))

I see nothing, but

return HttpResponse(ugettext("Hello"))

is working.

Why?

Answer 1

ugettext is used to load a translation of a string right now. ugettext_lazy returns an object that can eventually be turned into a string. You need that if the ugettext_lazy call is evaluated before the proper locale has been set.

ugettext_lazy can be used where you use a Unicode object. Double-check your HTML output, it might look like this:

<django.utils.functional...>

and the browser is ignoring it all as an unrecognized tag.

You don't need a lazy translation in this case, because you are immediately using the string. If you really want to continue with ugettext_lazy for some reason, try this:

return HttpResponse(ugettext_lazy("Hello").encode('utf-8'))

See the docs for more information.