How do I filter by a date range based on a dictionary value in python, otherwise filter a list by a dictionary?

Question

I have a dictionaries that look like this:

s_dates_dict = {17: datetime.date(2009,21,9,0,24), 19: datetime.datetime(2011,12,1,19,39,16), ....}  
e_dates_dict = {17: datetime.date(2010,25,9,10,24), 19: datetime.datetime(2012,1,11,17,39,16), ....}

I want to use these dictionaries to find the next record of type (A or B) after that date for each record. So it seems that I would be best off creating a query similar to below:

next_record_list = Tasks.objects.filter(date__range(s_dates_dict,e_dates_dict), client__in=client_list, task_type__in=[A,B])  

Whereby the dictionaries would cause a dynamically changing range to the pk referenced. I haven't found anything suggesting this is possible or efficient, so I am guessing the next best would be creating a list by eliminating the date range filter and then iterating a dictionary of the oldest values using a for statement and cutting off iteration of each record at the date referenced in dates_dict. But I haven't figured out a method to do this either. Could I get some suggestions of how to do this, or a totally different better method? Thanks.

EDIT:

client_list is a list of client objects.

Here is some of the models.py:

class Client(models.Model):
    user_name = models.CharField

class Task(models.Model):
    client = models.ForeignKey(
                               'Client',
                               )
    task_type = models.ForeginKey(
                                  'Task_Type',
                                  )
    date = models.DateTimeField(
                                 default = datetime.now(),
                                 blank = True,
                                 null = True,
                                 )

class Task_Type(models.Model):
    name = models.CharField  

Answer 1

I think I understand now. I am assuming client_list is actually a list of client objects. Someone may come up with a more efficient solution, but I would try something like this:

next_record = {}
for client in client_list:
    s = s_dates_dict[client.pk]
    e = e_dates_dict[client.pk]
    next_record[client.pk] = client.tasks_set.filter(date__range(s,e), task_type__in=[A,B])

This gives you a dict ( next_record ) where each key corresponds to a list of tasks. I am assuming there is a ForeignKey relationship between your Tasks and Client models.

Hopefully this works, if not, can you please post the code for your models?