python - django model filter with validate_unique -

there error says 'invalid syntax' newbie django , python... error in code? first if-block works second doesn't...

class membership(models.model):     person = models.foreignkey(person)     group = models.foreignkey(group)     is_joined = models.booleanfield(default = false) #if true, joined, else wish_member     is_master = models.booleanfield(default = false)     def __str__(self):         if(self.is_joined):             return self.person.name + " member in group " + self.group.name         return self.person.name + " wishes join in group " + self.group.name     def validate_unique(self, *args, **kwargs):         #super(person, self.person).validate_unique(*args, **kwargs)         #tests if there same person in same group.         if(self.__class__.objects.filter(person_id = self.person.id, group_id = self.group.id,).exists()):         raise validationerror(             {                 non_field_errors:                 ('the person exists.',)             }         )     elif(self.__class__objects.filter(is_master = true, group_id = self.group.id,).exists()):         raise validationerror(             {                 non_field_errors:                 ('the master exists.')             }) 

edits: noticed dot missing.leaving there credit found it. error occurs in:

elif(self.__class__.objects.filter(is_master = true, group_id = self.group.id,).exists()): 

you can use unique_together make set of fields, taken together, unique. in case, specify

class membership(models.model): ....      class meta:         unique_together = (                                ("person", "group"),                                ("is_master", "group"),                           ) 

this make sure person , group , is_master , group unique together. read more information here.