Python交互式模式运行Playwright报错：'PlaywrightContextManager'无chromium属性

问题场景 #

使用Playwright脚本爬取页面时可正常运行，但在Python交互式环境中执行以下代码时触发错误：

交互式执行代码：

>>> from playwright.sync_api import Playwright, sync_playwright, expect
>>> playwright = sync_playwright()
>>> browser = playwright.chromium.launch(headless=False)

报错信息：

Traceback (most recent call last):
  File "C:\Users\hpoddar\AppData\Local\Programs\Python\Python310\lib\idlelib\run.py", line 578, in runcode
    exec(code, self.locals)
  File "<pyshell#2>", line 1, in <module>
AttributeError: 'PlaywrightContextManager' object has no attribute 'chromium'

解决方案 #

方法1：在交互式环境中使用with语句（推荐）

和脚本中的写法一致，通过with语句自动获取Playwright实例并管理上下文：

from playwright.sync_api import sync_playwright

with sync_playwright() as playwright:
    # 启动浏览器
    browser = playwright.chromium.launch(headless=False)
    # 创建上下文和页面
    context = browser.new_context()
    page = context.new_page()
    page.goto("https://www.wikipedia.org/")
    
    # 执行你的爬取操作...
    
    # 清理资源
    context.close()
    browser.close()

方法2：手动操作上下文管理器

如果不想用with语句，可以手动调用上下文管理器的__enter__()方法获取Playwright实例，用完后再调用__exit__()清理：

from playwright.sync_api import sync_playwright

# 获取上下文管理器
playwright_manager = sync_playwright()
# 进入上下文，获取Playwright实例
playwright = playwright_manager.__enter__()

# 启动浏览器并执行操作
browser = playwright.chromium.launch(headless=False)
context = browser.new_context()
page = context.new_page()
page.goto("https://www.wikipedia.org/")

# 执行操作后清理资源
context.close()
browser.close()
# 退出上下文
playwright_manager.__exit__(None, None, None)

原因说明 #

sync_playwright()返回的是PlaywrightContextManager对象，而非直接的Playwright实例。只有通过with语句自动触发__enter__()方法，或者手动调用该方法，才能得到包含chromium、firefox等浏览器驱动属性的Playwright实例。脚本中的with语句会自动处理上下文的进入和退出，而交互式模式下直接赋值playwright = sync_playwright()得到的是管理器对象，自然没有chromium属性，导致报错。

内容的提问来源于stack exchange，提问作者Himanshu Poddar