How to clone a SQLAlchemy object including attached files?

Question

I want to clone a SQLAlchemy object:

That can be done like this:

report = reports.all()[0]
db.session.expunge(report)
make_transient(report)
report.id = None
db.session.add(report)
try:
    db.session.commit()
except SQLAlchemyError:
    db.session.rollback()

But table contains attachment column.

That attached files/images are stored in file system.

For newly created/cloned row, the file/image is not created/cloned in the file system.