# Just do it in the save method. ie, override the save method of Model class. def save(self, *args, **kwargs): self.username = self.username.lower() return super(User, self).save(*args, **kwargs)
Here is what the above code is Doing:
1. It is overriding the save method of the Model class.
2. It is calling the save method of the Model class.
3. It is converting the username to lowercase before saving it.