Reading attributes of a detached sqlalchemy object raises DetachedInstanceError

I am using short lived sqlalchemy sessions to add objects to a sqlite database. A few objects outlive the session in a readonly, detached state. Unfortunately, accessing attributes of a detached object throws an exception if the session has been closed. Here is a simplified code example

from sqlalchemy import Column, String, Integer, create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

Base = declarative_base()

class Foo(Base):
    __tablename__ = 'foo'
    id = Column(Integer, primary_key=True)
    name = Column(String, nullable=False)

engine = create_engine('sqlite:///foo.db', echo=False)
Base.metadata.create_all(engine)
Session = sessionmaker(bind=engine)
session = Session()

f = Foo(name='foo1')
print('state=transient : name=', f.name)
session.add(f)
print('state=pending : name=', f.name)
session.commit()
session.close()
print('state=detached : name=', f.name)

# output
state=transient : name= foo1
state=pending : name= foo1
Traceback (most recent call last):
  File "scratch_46.py", line 23, in <module>
    print('state=detached : name=', f.name)
  File "lib/python3.7/site-packages/sqlalchemy/orm/attributes.py", line 282, in __get__
    return self.impl.get(instance_state(instance), dict_)
  File "lib/python3.7/site-packages/sqlalchemy/orm/attributes.py", line 705, in get
    value = state._load_expired(state, passive)
  File "lib/python3.7/site-packages/sqlalchemy/orm/state.py", line 660, in _load_expired
    self.manager.deferred_scalar_loader(self, toload)
  File "lib/python3.7/site-packages/sqlalchemy/orm/loading.py", line 913, in load_scalar_attributes
    "attribute refresh operation cannot proceed" % (state_str(state))
sqlalchemy.orm.exc.DetachedInstanceError: Instance <Foo at 0x7f266c758ac8> is not bound to a Session; attribute refresh operation cannot proceed (Background on this error at: http://sqlalche.me/e/bhk3)

Oddly enough, the error is not thrown if I do either of these

• Read the name attribute between the commit and close calls while the object is in the persistent state
• Expunge the object from the session and leave the session open. Still detached state, but I can access the attribute.

Should I be able to read attributes of a detached object? Is there a way to have objects safely outlive transient sessions? I read the suggested link in the output, but it talks mostly about parent/child relationships.

I created a an issue on the sqlalchemy repo because I thought this was a bug at first, but now I am not so certain.