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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _remove_from(self, db, index, item):
 """ Remove `item` from `db` at `index`. Note: This function is inverse to :meth:`._add_to`. Args: db (dict-obj):
 Dict-like object used to connect to database. index (str):
 Index used to look in `db`. item (obj):
 Persistent object, which may be stored in DB. """

        with transaction.manager:
            row = db.get(index, None)

        if row is None:
            return

        with transaction.manager:
            if item in row:
                row.remove(item)

        with transaction.manager:
            if not row:
                del db[index]