SqlAlchemy: получить состояние экземпляра объекта

Ответ 1

Лучше использовать API проверки:

from sqlalchemy import inspect
state = inspect(obj)

# Booleans
state.transient
state.pending
state.detached
state.persistent

Ответ 2

[Обновить: этот ответ для версий до 0.8]

Нашел здесь:

from sqlalchemy.orm import object_session 
from sqlalchemy.orm.util import has_identity 

# transient: 
object_session(obj) is None and not has_identity(obj) 
# pending: 
object_session(obj) is not None and not has_identity(obj) 
# detached: 
object_session(obj) is None and has_identity(obj) 
# persistent: 
object_session(obj) is not None and has_identity(obj) 

Ответ 3

Другой вариант object_state, перенастройка InstanceState:

from sqlalchemy.orm.util import object_state

state = object_state(obj)
# here are the four states:
state.transient  # !session & !identity_key
state.pending    #  session & !identity_key
state.persistent #  session &  identity_key
state.detached   # !session &  identity_key
# and low-level attrs
state.identity_key
state.has_identity # bool(identity_key)
state.session

Ответ 4

другая опция, которая отображает ВСЕ объекты в определенных состояниях в сеансе: http://docs.sqlalchemy.org/en/latest/orm/session.html#session-attributes

# pending objects recently added to the Session
session.new

# persistent objects which currently have changes detected
# (this collection is now created on the fly each time the property is called)
session.dirty

# persistent objects that have been marked as deleted via session.delete(obj)
session.deleted

# dictionary of all persistent objects, keyed on their
# identity key
session.identity_map