Pyppeteer - 单击 link 后 运行 page.content() 时出错

Question

JS/Html的初学者，我试图通过 Pyppeteer0.2.5 (Python3.6.9/Chromium 87.0 在单击 link 后获取页面内容.4280.66) 使用以下代码：

import asyncio, pyppeteer, time
from pyppeteer import launch

async def main():
    browser = await launch(executablePath='/usr/bin/chromium-browser', headless=False)
    page = await browser.newPage()
    await page.goto('https://en.wikipedia.org')
    time.sleep(10)
    cont = await page.content()
    print(cont)
asyncio.get_event_loop().run_until_complete(main())

1. 如果我在 time.sleep(10) 期间没有点击或执行任何操作，10 秒后维基百科主要页面内容将按预期打印。
2. 如果我在 time.sleep(10) 期间（手动）单击任何 link，新页面会按预期打开，但 10 秒后我会收到 Python 错误（请参阅以下）。我在不同的网页上发生过同样的情况，在点击 Pyppeteer 而不是手动点击时也发生过同样的情况。单击 link 后 page.content() 失败是否有原因？

    Traceback (most recent call last):
      File "/home/martin/.local/lib/python3.6/site-packages/pyppeteer/execution_context.py", line 105, in evaluateHandle
        'userGesture': True,
    pyppeteer.errors.NetworkError: Protocol error (Runtime.callFunctionOn): Cannot find context with specified id
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File "To_delete/pythonProject/testtt.py", line 11, in <module>
        asyncio.get_event_loop().run_until_complete(main())
      File "/usr/lib/python3.6/asyncio/base_events.py", line 484, in run_until_complete
        return future.result()
      File "To_delete/pythonProject/testtt.py", line 9, in main
        cont = await page.content()
      File "/home/martin/.local/lib/python3.6/site-packages/pyppeteer/page.py", line 803, in content
        return await frame.content()
      File "/home/martin/.local/lib/python3.6/site-packages/pyppeteer/frame_manager.py", line 393, in content
        '''.strip())
      File "/home/martin/.local/lib/python3.6/site-packages/pyppeteer/frame_manager.py", line 309, in evaluate
        pageFunction, *args, force_expr=force_expr)
      File "/home/martin/.local/lib/python3.6/site-packages/pyppeteer/execution_context.py", line 54, in evaluate
        pageFunction, *args, force_expr=force_expr)
      File "/home/martin/.local/lib/python3.6/site-packages/pyppeteer/execution_context.py", line 108, in evaluateHandle
        _rewriteError(e)
      File "/home/martin/.local/lib/python3.6/site-packages/pyppeteer/execution_context.py", line 237, in _rewriteError
        raise type(error)(msg)
    pyppeteer.errors.NetworkError: Execution context was destroyed, most likely because of a navigation.

Answer 1

事实证明，我需要在 await page.content() 上方添加 await page.waitForNavigation() 才能使其正常工作。