When does a commit in SQLAlchemy Core get pushed to disk?

I have a program that is using SQLAlchemy Core to push information to an SQLite database. I am not using auto-commit transactions and am instead controlling the rate at which commits are made, as follows:

engine = create_engine("database")
connection = engine.connect()
transaction = connection.begin()
for index in range(0, num):
    connection.execute(EXAMPLE_INSERT)
transaction.commit()

Once I am done I am checking the database modify time so that I can check later to see if the database has been modified, which I am fetching using the following:

time.ctime(os.path.getmtime(full_path))

The issue that is occurring is that the database on disk seems to be getting modified after I am done with all the transactions and commits, which leads me to believe that the push to disk is occurring in some other process at some time later than the commit.

So is this correct, and if so, is there anyway to know when all the changes have been pushed to disk so I can get the correct modify time?