[Python] How do I create a both nullable and autoincremented column in SQLAlchemy?

I have a SQLAlchemy model like this:

class User(db.Model):
id: Mapped[int] = mapped_column(primary_key=True)
column: Mapped[int] = mapped_column(nullable=True, unique=True)


How can I make it so column column can be null, and will be an autoincremented integer value otherwise?

user1 = User() # here the `column` should be null
user2 = User() # missing code to make `column` autoincremented value, so for example if the previous user had it as NULL here it would be the first value, 0


I am using PostgreSQL and Flask-SQLAlchemy if this helps.

Continue reading...