从csv创建本地帐户，但如何省略已创建的帐户？

import csv
import subprocess

def create_local_accounts(csv_file):
    with open(csv_file, 'r') as file:
        reader = csv.reader(file)
        for row in reader:
            username = row[0]
            # 检查帐户是否已存在
            if check_account_exists(username):
                print(f"帐户 {username} 已存在，将被省略")
                continue
            # 创建本地帐户
            create_account(username)
            print(f"成功创建帐户 {username}")

def check_account_exists(username):
    # 调用操作系统命令来检查帐户是否存在
    result = subprocess.run(['getent', 'passwd', username], capture_output=True)
    return result.returncode == 0

def create_account(username):
    # 调用操作系统命令来创建本地帐户
    subprocess.run(['useradd', username])

# 使用示例
create_local_accounts('accounts.csv')