Public API for localtime

[Bradley Ayers <bradley.ayers@…>]

I think there should be a public API for converting timezone aware datetime objects to current timezone versions. This actually existed in django.utils.timezone as localtime, but was made private and removed from the documentation in https://code.djangoproject.com/changeset/17642

The current options for converting a datetime to the current timezone are:

1. Use Python's datetime.astimezone in conjunction with django.utils.timezone helpers:

from django.utils import timezone
local = dt.astimezone(timezone.get_current_timezone())

2. Use the public API for the localtime template filter via the privatish module django.template.defaultfilters:

from django.templatetags.tz import localtime
local = localtime(dt)

While (2) is much cleaner, I'd argue it's dirty to import from defaultfilters.

I propose re-publicising django.utils.timezone.localtime as a public API.

My use-case is generating PDFs that have datetimes in their content.

[Bradley Ayers <bradley.ayers@…>]

Correction:

django.template.defaultfilters import localtime

…should have been:

from django.templatetags.tz import localtime

EDIT(aaugustin): I made this change in the summary.

[Aymeric Augustin]

I made django.utils.timezone.localtime private because it contains some template-specific code.

I agree it would make sense to expose a similar function, without the template-specific bits, for general use.

This function actually has two variants: "default local time" or "current local time". As long as you don't have a timezone switcher for your end users, there's no difference between these. However, we should take this into account while extending the public API.

[Aymeric Augustin]

Anssi suggests that localtime should use the current time zone, which can be explicitly changed if necessary.

This would resolve the most common use case, and mirror the behavior of the template engine.

[Aymeric Augustin]

FIxed in 3e8b40f479a02e0f8c40ef3c7dae740082478b89.