How we add new column in django

to add a new column or file in Django after creating a table we should manage the following steps

1)  go into model.py and add field if filed is CharacterField then write

models.CharField(max_length=100, default='')

if field is DateTime then write following 
code 
models.DateTimeField(auto_now=True)

2)  python manage.py makemigrations appname


3)  python manage.py migrate