ISBNから書籍タイトルを取得する

books.py

import json

import requests

url = 'https://www.googleapis.com/books/v1/volumes?q=isbn:'

with open('list.txt', 'r') as f:
    for line in f.readlines():
        isbn = line.rstrip()
        res = requests.get(url + isbn, headers={"content-type": "application/json"}).json()
        title = res['items'][0]['volumeInfo']['title']
        print(f'{isbn},{title}')