vkill'blog

class Person(models.Model):
    name = models.CharField(max_length=50)

class Task(models.Model):
    assign = models.ForeignKey(Person,related_name='assign')
    accept = models.ForeignKey(Person,related_name='accept')

#use
>>> Person.objects.create(name='a')
<Person: Person object>
>>> Person.objects.create(name='b')
<Person: Person object>
>>> Person.objects.create(name='c')
<Person: Person object>
>>> Person.objects.create(name='d')
<Person: Person object>
>>> Task.objects.create(assign_id=1,accept_id=2)
<Task: Task object>
>>> Task.objects.create(assign_id=1,accept_id=3)
<Task: Task object>
>>> Task.objects.create(assign_id=1,accept_id=4)
<Task: Task object>
>>> Task.objects.create(assign_id=2,accept_id=3)
<Task: Task object>
>>> Task.objects.create(assign_id=2,accept_id=4)
<Task: Task object>

>>> Person.objects.get(name='b').assign.all()
[<Task: Task object>, <Task: Task object>]
>>> Person.objects.get(name='b').accept.all()
[<Task: Task object>]
>>> Task.objects.get(pk=1).assign.name
u'a'
>>> Task.objects.get(pk=1).accept.name
u'b'