在 Flask 应用程序中使用 Tortoise ORM 初始化数据库的正确方法是什么？

Question

在完成关于 Tortoise ORM 的章节之前，我学习了 Flask。我尝试将烧瓶和乌龟结合起来，但找不到合适的方法。当我调用异步函数时出现错误：

Traceback (most recent call last):
  File "C:\Users\Vladlen\python\pythonBasics\venv\lib\site-packages\flask\app.py", line 2464, in __call__
    return self.wsgi_app(environ, start_response)
  File "C:\Users\Vladlen\python\pythonBasics\venv\lib\site-packages\flask\app.py", line 2450, in wsgi_app
    response = self.handle_exception(e)
  File "C:\Users\Vladlen\python\pythonBasics\venv\lib\site-packages\flask\app.py", line 1867, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "C:\Users\Vladlen\python\pythonBasics\venv\lib\site-packages\flask\_compat.py", line 39, in reraise
    raise value
  File "C:\Users\Vladlen\python\pythonBasics\venv\lib\site-packages\flask\app.py", line 2447, in wsgi_app
    response = self.full_dispatch_request()
  File "C:\Users\Vladlen\python\pythonBasics\venv\lib\site-packages\flask\app.py", line 1952, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "C:\Users\Vladlen\python\pythonBasics\venv\lib\site-packages\flask\app.py", line 1821, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "C:\Users\Vladlen\python\pythonBasics\venv\lib\site-packages\flask\_compat.py", line 39, in reraise
    raise value
  File "C:\Users\Vladlen\python\pythonBasics\venv\lib\site-packages\flask\app.py", line 1950, in full_dispatch_request
    rv = self.dispatch_request()
  File "C:\Users\Vladlen\python\pythonBasics\venv\lib\site-packages\flask\app.py", line 1936, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "C:\Users\Vladlen\python\pythonBasics\lesson 19\views\doc_income.py", line 19, in new
    run_async(create_doc(request.values['account_id'], request.values['sum']))
  File "C:\Users\Vladlen\python\pythonBasics\venv\lib\site-packages\tortoise\__init__.py", line 634, in run_async
    loop = asyncio.get_event_loop()
  File "C:\Users\Vladlen\AppData\Local\Programs\Python\Python37\lib\asyncio\events.py", line 644, in get_event_loop
    % threading.current_thread().name)
RuntimeError: There is no current event loop in thread 'Thread-7'.

我的一段调用文档创建的代码：

@doc_income_app.route("new", methods=['GET', 'POST'])
def new():
    if request.method == 'GET':
        return render_template('doc_income/new.html')
    else:
        run_async(create_doc(request.values['account_id'], request.values['sum']))
        return jsonify(ok=True)


async def create_doc(account_id, sum):
    await db.init()
    doc = db.DocIncome(
        account_id=account_id,
        sum=sum
    )
    await doc.save()

我的问题是如何在 Flask 应用程序中调用异步数据库操作代码？

Answer 1

如何从同步代码调用异步代码？

创建事件循环，并在其中运行编写代码。问题是事件循环必须清除，所以任何计划的任务都会让它永远不会结束。（这样做有风险run_until_complete）基本上：

asyncio.get_event_loop().run_until_complete(create_doc(...))

乌龟提供的 run_async 助手也强制清理数据库，所以我不确定这是你想要的。

抱歉，您实际上是从一个不兼容的 colour 调用的，并且是开拓性的，我无法提供 texbook 答案。

我原来的回答： Flask 是一个同步 Python 框架，它不使用事件循环。考虑使用 asyncio-based 框架，例如 Quart/aiohttp/starlette，它和 Tortoise-ORM 使用相同的并发方法，它应该可以工作。

在 Flask 应用程序中使用 Tortoise ORM 初始化数据库的正确方法是什么？

What is the right way to initialize database using tortoise orm in flask app?

python-3.x

flask

tortoise-orm