When session.flush() failed on SQLAlchemy, should I call rollback?

Question

I know rollback called when session.commit() failed such as try-except block.
But when session.flush() failed, should I execute rollback()?

try:
    session.flush()
except IntegrityError:
    session.rollback()

Answer 1

The accepted answer is not entirely correct. The documentation about Session.flush() is a bit misleading about this.

Upon failure, the transaction (i.e. the database transaction) will be rolled back (by the database). Its python counterpart, the Session object itself will then be in an "inactive" state and, according to the documentation 1 2

must be explicitly rolled back by the calling application, in the same way that it would otherwise need to be explicitly committed if a failure had not occurred.

It does further acknowledge that

this is a common error when using the ORM

Answer 2

Failed flush is always rolled back, you do not need to do it yourself:

http://docs.sqlalchemy.org/en/latest/orm/session_api.html#sqlalchemy.orm.session.Session.flush

Database operations will be issued in the current transactional context and do not affect the state of the transaction, unless an error occurs, in which case the entire transaction is rolled back. You may flush() as often as you like within a transaction to move changes from Python to the database’s transaction buffer.