Django: Filter Model on Date Range

A generic filter function to filter query results by data ranges

I'm sure this is in the documentation somewhere but it wasn't totally obvious to me and I knew there had to be an easy way to filter a model based on a date range. I'm in the process of filtering transactions for Inzolo and giving the user options for the following date filters:

Month to date
Last month
Past week
Past 2 weeks
Last 30 days
Last 60 days
Last 90 days
All transactions

There really is easy ways to do all of these, but they are slightly different. What I got hung up on was the range. My assumption would be to do something like .filter(date >= begin_date, date <= today) but that obviously won't work. I finally found what I needed with the range function.

So to get each of the filters to work, I created a filter function that looks like this (I'll let you read between the lines to figure out what it is doing):

1def filter_trans(request, trans):
2    today = date.today()
3    if 'filter' in request.POST:
4        fltr = request.POST['filter']
5        if fltr == 'this_month':
6            trans = trans.filter(date__year=today.year, date__month=today.month)
7        elif fltr == 'last_month':
8            year = today.year
9            month = today.month - 1
10            if month == 0:
11                month = 12
12                year = year - 1
13            trans = trans.filter(date__year=year, date__month=month)
14        elif fltr[:4] == 'last':
15            days = int(fltr[4:])
16            trans = filter_trans_days(trans, today, days)
17        elif fltr == 'all':
18            return trans
19    else:
20        trans = trans.filter(date__year=today.year, date__month=today.month)
21    return trans
22
23def filter_trans_days(trans, today, days):
24    days = timedelta(days=days)
25    begin = today - days
26    return trans.filter(date__range=(begin, today))