顾客姓名：John Smith
创建一个程序来获取客户账户余额。
# 程序来获取客户账户余额

def fetch_account_balance(name):
    # 从数据库中获取客户数据
    customer_data = get_data_from_db(name)

    # 获取客户账户余额
    customer_balance = customer_data['account_balance']

    # 返回客户账户余额
    return customer_balance

# 获取 John Smith 的账户余额
john_smith_balance = fetch_account_balance('John Smith')
print(john_smith_balance)