An example showing how to use @hybrid_property in SQLAlchemy.

post_pv

#!/usr/bin/env python                                                                        
# -*- coding: utf-8 -*-

from sqlalchemy import Column, Integer
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import Session
from sqlalchemy.ext.hybrid import hybrid_property

Base = declarative_base()


class Post(Base):
    
    __tablename__ = 'post'

    id = Column(Integer, primary_key=True)
    fake_pv = Column(Integer, default=0)
    actual_pv = Column(Integer, default=0)

    @hybrid_property
    def pv(self):
        """Use `fake_pv` if it's configured, otherwise, use `actual_pv`."""
        # Caution:
        # TypeError("Boolean value of this clause is not defined")
        # will be raised if the next line is rewritten as
        # "if self.fake_pv > 0:"
        if (self.fake_pv > 0) is True:
            return self.fake_pv
        else:
            return self.actual_pv
            

def get_pop_posts(session):
    session.query(Post).order_by(Post.pv.desc())
    
    
if __name__ == '__main__':
    posts = get_pop_posts(Session())
    print(posts)

Hey, thanks for posting this. It pointed me in the right direction, but I still had some problems and that's when I came across this:
http://docs.sqlalchemy.org/en/latest/orm/mapped_sql_expr.html
It says some hybrid properties need to exist alongside a SQL expression constructor in order to work well.