broken csv loading

from src.swen344_db_utils import connect, exec_commit
import csv


def seed_users():
    """Seed default users into db"""
    users = [
        (
            "Ada Lovelace",
            "[email protected]",
        ),
        (
            "Mary Shelley",
            "[email protected]",
        ),
        (
            "Jackie Gleason",
            "[email protected]",
        ),
        (
            "Art Garfunkel",
            "[email protected]",
        ),
    ]
    for user in users:
        exec_commit(
            """
            INSERT INTO library_users (name, email)
            VALUES (%s, %s)
            ON CONFLICT (email) DO NOTHING
            """,
            user
        )


def seed_inventory(path_to_csv):
    """Given a CSV file, add each book and it's data into the csv one row at a time."""
    conn = connect()
    cur = conn.cursor()

    # Clear inventory table
    cur.execute("TRUNCATE TABLE library_inventory RESTART IDENTITY CASCADE;")

    # Read from csv file and populate the inventory
    with open(path_to_csv) as inventory:
        reader = csv.DictReader(inventory)
        for row in reader:
            cur.execute(
                "INSERT INTO library_inventory (Title, Comment, Category, Subcategory, Copies) VALUES (%s, %s, %s, %s, %s)"
                "RETURNING InventoryID",
                (
                    row["Title"],
                    row["Comments"],
                    row["Category"],
                    row["Sub-category"],
                    row["Copies"],
                ),
            )
            
            author = row["author(s)"]
            
            authors = [a.strip() for a in author.split(',')]
            inventory_id = cur.fetchone()[0]
            
            for author in authors:
                cur.execute(
                    "INSERT INTO library_authors (Name) VALUES (%s)"
                    "ON CONFLICT (name) DO UPDATE SET NAME = EXCLUDED.Name RETURNING AuthorID",
                    (author, )
                )
                author_id = cur.fetchone()[0]
                
                cur.execute(
                    "INSERT INTO library_book_authors (InventoryID, AuthorID) VALUES (%s, %s)"
                    "ON CONFLICT DO NOTHING",
                    (inventory_id, author_id)
                )

    conn.commit()
    cur.close()
    conn.close()


def main():
    seed_users()
    seed_inventory("db/Library.csv")


if __name__ == "__main__":
    main()