SQLAlchemy set default value for postgres JSON column

Question

I want to set the default value of my SQLAlchemy postgres JSON column to an empty dictionary.

from sqlalchemy.dialects.postgresql import JSON

info = Column(JSON, default='{}')
info = Column(JSON, default={})

Neither of these work.

Answer 1

Using default=lambda: {} works. Credit goes to univerio in the comments.

Answer 2

The easiest way I've found to define a JSON not null (if applies) column with a default {} value is (tested with SQLAlchemy 1.3.x):

info = db.Column(JSON, nullable=False, server_default='{}')