class number_of_children_in_family(Variable):
value_type = int
definition_period = MONTH
entity = Family
label = u"The number of children in a family"
def formula(families, period):
return families.nb_persons(role=Family.CHILD)
class is_a_child_in_a_family(Variable):
value_type = bool
entity = Person
label = u"person is a child in a family"
definition_period = ETERNITY
def formula(person, period):
return person.has_role(Family.CHILD)