1
Seems that you are doing it the wrong way.
You have some class in which you have this keyword field which is efffectively a many to many relationship with another model (something like ‘Tags’)
How you use it is:
lets say the class is Fruits then you will have to take the instance of that class say Mango(the object you want to create keywords for)
Then you use:
Mango.keywords.add(ss)
or
self.keywords.add(ss)
Source:stackexchange.com