using model method to instantiate object in Django -

i have 2 classes defined in models.py file:

class branch_circle(models.model):     ...     trunk_circle = models.foreignkey('trunk_circle', null=true)  class trunk_circle(models.model):     ...     def create_branch_circle(self):         branch_circle = branch_circle(trunk_circle=self)         branch_circle.save()         return branch_circle 

using shell instantiate trunk_circle object first, call 'create_branch_circle' method , expect create branch_circle object. doesn't:

import trunk_circle import branch_circle  r = trunk_circle s = r.create_branch_circle 

when call branch_circle.objects.all() empty. also, type of 's' <bound method trunk_circle.create_branch_circle of <trunk_circle: trunk_circle object>>

to instantiate object or call method have use brackets ():

r = trunk_circle() s = r.create_branch_circle()