group objects with same field value

Question

I've got two models like these:

class Schedule(models.Model):
    name = models.CharField(_('name'), blank=True, max_length=15)


class Day(models.Model):
    DAYS_OF_THE_WEEK = (
        (0, _('Monday')),
        (1, _('Tuesday')),
        (2, _('Wednesday')),
        (3, _('Thursday')),
        (4, _('Friday')),
        (5, _('Saturday')),
        (6, _('Sunday')),
    )
    schedule = models.ForeignKey(Schedule, blank=True, null=True, verbose_name=_('schedule'))
    day = models.SmallIntegerField(_('day'), choices=DAYS_OF_THE_WEEK)
    opening = models.TimeField(_('opening'), blank=True)
    closing = models.TimeField(_('closing'), blank=True)

It's possible that a schedule can have two Day objects like so:

Day(schedule=1, day=0, opening=datetime.time(7, 30), closing=datetime.time(10, 30)) Day(schedule=1, day=0, opening=datetime.time(12, 30), closing=datetime.time(15, 30))

like different shifts on the same day.

If I iterate them now i'll get two entries of day 0, like so [day for day in schedule] [0, 0, 1, 2, 3, 4, 5, 6]

How can I create a queryset so it'll group same days together and keep their attributes?

[day for day in schedule]
[0 (two entries), 1, 3, 4, 5, 6]

Maybe something like

[id: [day], id: [day]]

Answer 1

The code I ended up using is this:

from itertools import groupby

day_set = store.schedule_set.all()[0].day_set.all()
    schedule = dict()
    for k, v in groupby(day_set, lambda x: x.day):
        schedule[k] = list(v)

and sending schedule to the template for rendering, which works like a charm.

Answer 2

You can group them at template level, using {% regroup %} or {% for %}-loop with {% ifchanged %} tag.

In Python code use groupby.