Python Google Classroom API "TypeError:列表索引必须是整数或切片，而不是字符串“

from googleapiclient.discovery import build
from google.oauth2.credentials import Credentials

# 使用你的Google API凭证进行身份验证
credentials = Credentials.from_authorized_user_file('credentials.json')

# 构建Google Classroom API客户端
service = build('classroom', 'v1', credentials=credentials)

# 创建一个课程
course = {
    'name': 'My Course',
    'section': 'Section 1',
    'descriptionHeading': 'Welcome to My Course',
    'description': 'This is a sample course created using Python Google Classroom API',
    'room': 'Room 101',
    'ownerId': 'me',
    'courseState': 'ACTIVE'
}

created_course = service.courses().create(body=course).execute()
print('Created course: %s (%s)' % (created_course.get('name'), created_course.get('id')))