Pycharm Pro SQLAlchemy fragility

pycharm_sqlalchemy.py

import weakref
from sqlalchemy import \
    Column, Integer, String, MetaData, ForeignKey
from sqlalchemy.ext.declarative import \
    declarative_base, DeclarativeMeta, declared_attr
from sqlalchemy.orm import \
    relationship
# noinspection PyProtectedMember
from sqlalchemy.ext.declarative.api import \
    _declarative_constructor

db_Column = Column
db_Integer = Integer

Model = declarative_base()


class Person(Model):
    __tablename__ = 'person'
    id = Column(Integer, primary_key=True)

    name = Column(String)
    age = Column(Integer)
    age2 = Column(db_Integer)
    age3 = db_Column(db_Integer)


Person()


class Account(Model):
    __tablename__ = 'account'
    id = Column(Integer, primary_key=True)


class LBBAccountStratMixin:
    @declared_attr
    def account_id(self):
        return Column(Integer, ForeignKey(Account.id))

    @declared_attr
    def account(self):
        return relationship(Account, self.account_id)


class LBBAccountStratNullableMixin(LBBAccountStratMixin):
    @declared_attr
    def account_id(self):
        return Column(Integer, ForeignKey(Account.id), nullable=True)


class Person2(LBBAccountStratNullableMixin, Model):
    __tablename__ = 'person2'

    id = Column(Integer, primary_key=True)
    name = Column(String)


Person2(id=3, name='asdf', account_id=2)


class DeclarativeMeta2(DeclarativeMeta):
    pass


def declarative_base2(bind=None, metadata=None, mapper=None, cls=object,
                      name='Base', constructor=_declarative_constructor,
                      class_registry=None,
                      metaclass=DeclarativeMeta2):
    lcl_metadata = metadata or MetaData()
    if bind:
        lcl_metadata.bind = bind

    if class_registry is None:
        class_registry = weakref.WeakValueDictionary()

    bases = not isinstance(cls, tuple) and (cls,) or cls
    class_dict = dict(_decl_class_registry=class_registry,
                      metadata=lcl_metadata)

    if isinstance(cls, type):
        class_dict['__doc__'] = cls.__doc__

    if constructor:
        class_dict['__init__'] = constructor
    if mapper:
        class_dict['__mapper_cls__'] = mapper

    return metaclass(name, bases, class_dict)


Model2 = declarative_base2()


class Person3(Model2):
    __tablename__ = 'person3'
    id = Column(Integer, primary_key=True)

    name = Column(String)


Person3()