decorators.py

from functools import wraps
from django.db.models.signals import pre_save

def full_clean_on_save(cls):
    """ 
    Class decorator that automatically calls full_clean() when a model is saved.
    """
    def connect(signal, func):
        cls.func = staticmethod(func)
        @wraps(func)
        def wrapper(sender, **kwargs):
            return func(kwargs.get('instance'))
        signal.connect(wrapper, sender=cls)
        return wrapper

    connect(pre_save, cls.full_clean)
    
    return cls 

#---------

# Example usage
@full_clean_on_save
class MyModel(models.Model):
    tits = CharField(max_length=5, default="(.Y.)")