如何使用Python的nodriver库保存和加载会话（Cookies）？

问题说明 #

作为Python新手，尝试用nodriver保存和加载会话Cookie时，发现网上示例代码过时，尝试多种方法后仍未能实现第二次启动程序时自动处于登录状态，现有可执行登录代码如下，需添加Cookie持久化逻辑：

# 原代码
import asyncio
import nodriver as uc

user = "User"
password = "passwort"


async def type_text(element, text):
    for char in text:
        await element.send_keys(char)


async def main():
    browser = None
    try:
        browser = await uc.start()
        page = await browser.get('https://html-php.de/php/zb_php_f/index.php')

        email_field = await page.select("input[name=a_nick]")
        password_field = await page.select("input[name=a_pass]")
        login_task = None

        if email_field and password_field:
            await type_text(email_field, user)
            await type_text(password_field, password)

            login_button = await page.select("input[type=submit]")
            if login_button:
                login_task = asyncio.create_task(login_button.click())

        if login_task:
            await login_task

    except Exception as e:
        print(f"Error during login: {e}")
    finally:
        if browser:
            await asyncio.sleep(10)
            await browser.stop()


if __name__ == '__main__':
    uc.loop().run_until_complete(main())

解决方案 #

通过page.get_cookies()获取登录后的Cookie并保存为JSON文件；启动程序时先读取该文件，用page.add_cookie()将Cookie注入浏览器会话，实现免登录。

修改后完整代码 #

import asyncio
import nodriver as uc
import json
import os

# 配置信息
user = "User"
password = "passwort"
COOKIE_FILE = "session_cookies.json"
TARGET_URL = 'https://html-php.de/php/zb_php_f/index.php'


async def type_text(element, text):
    for char in text:
        await element.send_keys(char)


def save_cookies(cookies, file_path):
    """将Cookie保存到JSON文件"""
    with open(file_path, 'w', encoding='utf-8') as f:
        json.dump(cookies, f, indent=2)


def load_cookies(file_path):
    """从JSON文件加载Cookie"""
    if not os.path.exists(file_path):
        return None
    with open(file_path, 'r', encoding='utf-8') as f:
        return json.load(f)


async def is_logged_in(page):
    """判断是否已登录：检查登录框是否不存在"""
    try:
        email_field = await page.select("input[name=a_nick]", timeout=2)
        return not email_field  # 找不到登录框则视为已登录
    except Exception:
        return True


async def main():
    browser = None
    try:
        browser = await uc.start()
        page = await browser.get(TARGET_URL)

        # 尝试加载本地Cookie
        cookies = load_cookies(COOKIE_FILE)
        if cookies:
            for cookie in cookies:
                # 修正Cookie域名，确保与目标网站匹配
                if 'domain' not in cookie or cookie['domain'].startswith('.'):
                    cookie['domain'] = '.html-php.de'
                try:
                    await page.add_cookie(cookie)
                except Exception as e:
                    print(f"添加Cookie失败: {e}")
            # 重新加载页面使Cookie生效
            await page.get(TARGET_URL)

        # 检查登录状态
        if not await is_logged_in(page):
            # 执行登录流程
            email_field = await page.select("input[name=a_nick]")
            password_field = await page.select("input[name=a_pass]")
            login_task = None

            if email_field and password_field:
                await type_text(email_field, user)
                await type_text(password_field, password)

                login_button = await page.select("input[type=submit]")
                if login_button:
                    login_task = asyncio.create_task(login_button.click())
                    await login_task
                    # 等待页面加载完成后保存Cookie
                    await asyncio.sleep(2)
                    session_cookies = await page.get_cookies()
                    save_cookies(session_cookies, COOKIE_FILE)
                    print("已保存登录Cookie")
            else:
                print("未找到登录输入框，页面结构可能已变化")
        else:
            print("已通过Cookie自动登录")

        await asyncio.sleep(10)

    except Exception as e:
        print(f"执行出错: {e}")
    finally:
        if browser:
            await browser.stop()


if __name__ == '__main__':
    uc.loop().run_until_complete(main())

关键说明 #

1. Cookie持久化：用JSON文件存储Cookie，save_cookies和load_cookies函数负责读写操作
2. Cookie有效性：添加Cookie时需确保domain参数与目标网站匹配，否则Cookie无法生效
3. 登录状态判断：通过检查登录输入框是否存在判断登录状态，可根据目标网站实际结构调整逻辑
4. 异常处理：处理Cookie文件不存在、添加Cookie失败等场景，避免程序崩溃

内容的提问来源于stack exchange，提问作者Aca