Tengo una consulta de unión interna sin procesar con conteo, escrita directamente en Postgres SQL:

    SELECT "films"."id" AS "megaId", 
           COUNT("filmComments"."id") AS "numOfComments" 
      FROM "films"
INNER JOIN "filmComments" 
        ON ("films"."id" = "filmComments"."filmId") 
  GROUP BY "films"."id";

¿Cómo puedo hacer lo mismo, usando SqlAlchemy normal, sinconnection.execute(sqlCode)?

PD Mis clases de tabla SqlAlchemy:

from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
from sqlalchemy import Column, Integer, String, Date, Float

class Film(Base):
    __tablename__ = "films"
    id = Column(Integer, primary_key = True)
    name = Column(String)
    rating = Column(Float)
    marksCount = Column(Integer)
    commentsCount = Column(Integer, index=True)


class FilmComment(Base):
    __tablename__ = "filmComments"
    id = Column(Integer, primary_key = True)
    filmId = Column(Integer, index=True)
    rating = Column(Integer, index=True)
    text = Column(String)
    votesUp = Column(Integer)
    votesDown = Column(Integer)
    userId = Column(Integer)
    date = Column(Date)