Django: Total birthdays each day for the next 30 days - django

Question

I've got a model similar to this:
class Person(models.Model):
name = models.CharField(max_length=40)
birthday = DateTimeField() # their next birthday
I would like to get a list of the total birthdays for each day for the next 30 days. So for example, the list would look like this:
[[9, 0], [10, 3], [11, 1], [12, 1], [13, 5], ... #30 entries in list
Each list entry in the list is a date number followed by the number of birthdays on that day. So for example on the 9th of May there are 0 birthdays.
UPDATES
My db is sqlite3 - will be moving to postgres in the future.

Answer 1

from django.db.models import Count
import datetime
today = datetime.date.today()
thirty_days = today + datetime.timedelta(days=30)
birthdays = dict(Person.objects.filter(
birthday__range=[today, thirty_days]
).values_list('birthday').annotate(Count('birthday')))
for day in range(30):
date = today + datetime.timedelta(day)
print "[%s, %s]" % (date, birthdays.get(date, 0))

Answer 2

I would get the list of days and birthday count this way:
from datetime import date, timedelta
today = date.today()
thirty_days = today + timedelta(days=30)
# get everyone with a birthday
people = Person.objects.filter(birthday__range=[today, thirty_days])
birthday_counts = []
for date in [today + timedelta(x) for x in range(30)]:
# use filter to get only birthdays on given date's day, use len to get total
birthdays = [date.day, len(filter(lambda x: x.birthday.day == date.day, people))]
birthday_counts.append(birthdays)

Answer 3

Something like this --
from datetime import date, timedelta
class Person(models.Model):
name = models.CharField(max_length=40)
birthday = models.DateField()
#staticmethod
def upcoming_birthdays(days=30):
today = date.today()
where = 'DATE_ADD(birthday, INTERVAL (YEAR(NOW()) - YEAR(birthday)) YEAR) BETWEEN DATE(NOW()) AND DATE_ADD(NOW(), INTERVAL %S DAY)'
birthdays = Person.objects.extra(where=where, params=[days]).values_list('birthday', flat=True)
data = []
for offset in range(0, days):
i = 0
d = today + timedelta(days=offset)
for b in birthdays:
if b.day == d.day and b.month == d.month:
i += 1
data.append((d.day, i))
return data
print Person.upcoming_birthdays()

Answer 4

(Queryset of people with a birthday in the next X days)
Found cool solution for this!
For me it works!
from datetime import datetime, timedelta
import operator
from django.db.models import Q
def birthdays_within(days):
now = datetime.now()
then = now + timedelta(days)
# Build the list of month/day tuples.
monthdays = [(now.month, now.day)]
while now <= then:
monthdays.append((now.month, now.day))
now += timedelta(days=1)
# Tranform each into queryset keyword args.
monthdays = (dict(zip(("birthday__month", "birthday__day"), t))
for t in monthdays)
# Compose the djano.db.models.Q objects together for a single query.
query = reduce(operator.or_, (Q(**d) for d in monthdays))
# Run the query.
return Person.objects.filter(query)
But it get a list of persons that have a birthday in date range. You should change a bit.