[Python] Adding metadata (annotations) to python variables

I have a sqlalchemy class User which inherits from Model.

class Model:
@declared_attr
def __tablename__(self):
return self.__name__.lower()

_id = Column(Integer, primary_key=True, autoincrement=True)
in_utc = Column(BigInteger, default=time())
out_utc = Column(BigInteger, default=config['MAX_UTC'])

def to_dict(self):
return {k: v for k, v in vars(self).items() if not isinstance(v, InstanceState)}

class User(declarative_base(), Model):
email = Column(String)
password = Column(String)
name = Column(String)


The reason for the parent class is to add some columns that are common across the tables and also the to_dict() method which creates a dictionary from the columns.

However I do not want the password column to be included when calling user.to_dict().

Is there any way to annotate the password Column (like in Java reflection) so that to_dict() knows to ignore it?

For example:

class User(declarative_base(), Model):
email = Column(String)

[IgnoredInOutput()]
password = Column(String)

name = Column(String)


I've now overridden to_dict in the User class to remove the password column for this model.

Continue reading...