import csv

with open('books.csv') as books_csv:
  books_reader = csv.DictReader(books_csv, delimiter='@')
  isbn_list = []
  for book in books_reader:
    isbn_list.append(book['ISBN'])
import csv

with open('books.csv') as books_csv:
  books_reader = csv.DictReader(books_csv, delimiter='@')
  isbn_list = []
  for book in books_reader:
    isbn_list.append(book['ISBN'])