How to use the huey.crontab function in huey

@periodic_task(crontab(minute='*/2'))
def every_other_minute():
    tprint('This task runs every 2 minutes.', 35)

@huey.periodic_task(crontab(hour='3', minute=str(30 + random.randrange(-30, +30))))
def download_wsusscan_crontab():
    descr = make_dl_task_descr()
    return download_wsusscan(task_descr=descr)

from app.persistence.events_manager import get_all_events, add_scrambles_to_scramble_pool
from app.util.events.resources import get_event_resource_for_name, EVENT_COLL

from . import huey
from .admin_notification import notify_admin, AdminNotificationType

# -------------------------------------------------------------------------------------------------

ScramblePoolTopOffInfo = namedtuple('ScramblePoolTopOffInfo', ['event_id', 'event_name', 'num_scrambles'])

# In dev environments, run the task to check the scramble pool every minute.
# In prod, run it every hour (frequently enough so that new events get populated with scrambles quickly)
if app.config['IS_DEVO']:
    CHECK_SCRAMBLE_POOL_SCHEDULE = crontab(minute="*/1")  # Once every minute
else:
    CHECK_SCRAMBLE_POOL_SCHEDULE = crontab(hour="*/1", minute="0")   # Once every hour

# -------------------------------------------------------------------------------------------------

@huey.periodic_task(CHECK_SCRAMBLE_POOL_SCHEDULE)
def check_scramble_pool():
    """ A periodic task to check the pre-generated pool of scrambles for all events. If the pool
    is too low for any event, enqueue a task to generate more scrambles for those events. """

    event_scramble_msgs = list()

    for event in get_all_events():

        # Don't pre-generate COLL scrambles. The fact we need a specific COLL each week, and that
        # rotates weekly, makes this more difficult than it needs to be. We'll just generate them
        # on the fly during competition generation, since it's fast anyway
        if event.name == EVENT_COLL.name:

@db_periodic_task(crontab(minute='0', hour='*/12'))
def read_all_assets():
    for x in EveUser.objects.filter(scope_read_assets=True):
        read_assets_for_character(x)

@db_periodic_task(crontab(minute="*"))
def dispatch_push_tasks():
    generic_push_targets = GenericPushTarget.objects.filter(status=GenericPushTarget.STATUS_ACTIVE).all()
    brewers_friend_push_targets = BrewersFriendPushTarget.objects.filter(status=BrewersFriendPushTarget.STATUS_ACTIVE).all()
    brewfather_push_targets = BrewfatherPushTarget.objects.filter(status=BrewfatherPushTarget.STATUS_ACTIVE).all()

    # Run through the list of generic push targets and trigger a (future) data send for each
    for target in generic_push_targets:
        if timezone.now() >= (target.last_triggered + datetime.timedelta(seconds=target.push_frequency)):
            target.last_triggered = timezone.now()
            target.save()

            # Queue the generic_push_target_push task (going to do it asynchronously)
            generic_push_target_push(target.id)

    # Run through the list of Brewer's Friend push targets and trigger a (future) data send for each
    for target in brewers_friend_push_targets:

@db_periodic_task(crontab(minute='*'))
def sendReminderEmails():

    if not getConstant('general__enableCronTasks'):
        return

    reminders_needed = EventReminder.objects.filter(**{
        'time__lte': timezone.now(),
        'completed':False,
        'notifyList__isnull': False})
    if reminders_needed:
        for note in reminders_needed:
            for user in note.notifyList.all():
                sent = sendReminderEmailToUser(user,note)
                if sent:
                    # Mark reminder as sent so it won't be sent twice.
                    note.completed = True