带有 Python 龙卷风的自定义 404 错误页面

Question

我正在尝试使用 python tornado 实现自定义 404 页面。文档说：“default_handler_class 和 default_handler_args：如果没有找到其他匹配项，将使用此处理程序；使用它来实现自定义 404 页面（Tornado 3.2 中的新功能）。”。没有关于处理程序需要如何工作的好信息。我尝试使用此代码：

    class defaultHandler(tornado.web.RequestHandler):
        def __init__(self, arg2, arg3):
            print("Called default handler")
            self.arg2 = arg2
            self.arg3 = arg3
    
        def get(self):
            self.write("404 - my thing")

使用这个龙卷风配置：

 return tornado.web.Application([
        (r"/main", MainHandler),
        (r"/update_kurse", updateCallback),
        (r"/", LoginPage),
    ], static_path=os.path.join(os.path.dirname(__file__), "static"),
    template_path=os.path.join(os.path.dirname(__file__), "templates"),
    default_handler_class=defaultHandler)

这会导致错误：

ERROR:tornado.application:Uncaught exception
Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\http1connection.py", line 273, in _read_message
    delegate.finish()
  File "C:\Users\******\lib\site-packages\tornado\routing.py", line 268, in finish
    self.delegate.finish()
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 2297, in finish
    self.execute()
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 2337, in execute
    return self.handler._prepared_future
AttributeError: 'defaultHandler' object has no attribute '_prepared_future'
ERROR:tornado.application:Error in exception logger
Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1665, in _execute
    if self.request.method not in self.SUPPORTED_METHODS:
AttributeError: 'function' object has no attribute 'method'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1752, in _handle_request_exception
    self.log_exception(*sys.exc_info())
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1790, in log_exception
    self._request_summary(),
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1740, in _request_summary
    self.request.method,
AttributeError: 'function' object has no attribute 'method'
ERROR:tornado.application:Exception in exception handler
Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1665, in _execute
    if self.request.method not in self.SUPPORTED_METHODS:
AttributeError: 'function' object has no attribute 'method'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1708, in _execute
    self._handle_request_exception(e)
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1757, in _handle_request_exception
    if self._finished:
AttributeError: 'defaultHandler' object has no attribute '_finished'
ERROR:asyncio:Exception in callback _HandlerDelegate.execute.<locals>.<lambda>(<Task finishe...ed_future'",)>) at C:\Users\******\lib\site-packages\tornado\web.py:2333
handle: <Handle _HandlerDelegate.execute.<locals>.<lambda>(<Task finishe...ed_future'",)>) at C:\Users\******\lib\site-packages\tornado\web.py:2333>
Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1665, in _execute
    if self.request.method not in self.SUPPORTED_METHODS:
AttributeError: 'function' object has no attribute 'method'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\******\lib\asyncio\events.py", line 145, in _run
    self._callback(*self._args)
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 2333, in <lambda>
    fut.add_done_callback(lambda f: f.result())
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1714, in _execute
    if self._prepared_future is not None and not self._prepared_future.done():
AttributeError: 'defaultHandler' object has no attribute '_prepared_future'
Called default handler
ERROR:tornado.application:Uncaught exception
Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\http1connection.py", line 273, in _read_message
    delegate.finish()
  File "C:\Users\******\lib\site-packages\tornado\routing.py", line 268, in finish
    self.delegate.finish()
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 2297, in finish
    self.execute()
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 2337, in execute
    return self.handler._prepared_future
AttributeError: 'defaultHandler' object has no attribute '_prepared_future'
ERROR:tornado.application:Error in exception logger
Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1665, in _execute
    if self.request.method not in self.SUPPORTED_METHODS:
AttributeError: 'function' object has no attribute 'method'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1752, in _handle_request_exception
    self.log_exception(*sys.exc_info())
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1790, in log_exception
    self._request_summary(),
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1740, in _request_summary
    self.request.method,
AttributeError: 'function' object has no attribute 'method'
ERROR:tornado.application:Exception in exception handler
Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1665, in _execute
    if self.request.method not in self.SUPPORTED_METHODS:
AttributeError: 'function' object has no attribute 'method'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1708, in _execute
    self._handle_request_exception(e)
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1757, in _handle_request_exception
    if self._finished:
AttributeError: 'defaultHandler' object has no attribute '_finished'
ERROR:asyncio:Exception in callback _HandlerDelegate.execute.<locals>.<lambda>(<Task finishe...ed_future'",)>) at C:\Users\******\lib\site-packages\tornado\web.py:2333
handle: <Handle _HandlerDelegate.execute.<locals>.<lambda>(<Task finishe...ed_future'",)>) at C:\Users\******\lib\site-packages\tornado\web.py:2333>
Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1665, in _execute
    if self.request.method not in self.SUPPORTED_METHODS:
AttributeError: 'function' object has no attribute 'method'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\******\lib\asyncio\events.py", line 145, in _run
    self._callback(*self._args)
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 2333, in <lambda>
    fut.add_done_callback(lambda f: f.result())
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1714, in _execute
    if self._prepared_future is not None and not self._prepared_future.done():
AttributeError: 'defaultHandler' object has no attribute '_prepared_future'
Called default handler
ERROR:tornado.application:Uncaught exception
Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\http1connection.py", line 273, in _read_message
    delegate.finish()
  File "C:\Users\******\lib\site-packages\tornado\routing.py", line 268, in finish
    self.delegate.finish()
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 2297, in finish
    self.execute()
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 2337, in execute
    return self.handler._prepared_future
AttributeError: 'defaultHandler' object has no attribute '_prepared_future'
ERROR:tornado.application:Error in exception logger
Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1665, in _execute
    if self.request.method not in self.SUPPORTED_METHODS:
AttributeError: 'function' object has no attribute 'method'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1752, in _handle_request_exception
    self.log_exception(*sys.exc_info())
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1790, in log_exception
    self._request_summary(),
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1740, in _request_summary
    self.request.method,
AttributeError: 'function' object has no attribute 'method'
ERROR:tornado.application:Exception in exception handler
Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1665, in _execute
    if self.request.method not in self.SUPPORTED_METHODS:
AttributeError: 'function' object has no attribute 'method'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1708, in _execute
    self._handle_request_exception(e)
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1757, in _handle_request_exception
    if self._finished:
AttributeError: 'defaultHandler' object has no attribute '_finished'
ERROR:asyncio:Exception in callback _HandlerDelegate.execute.<locals>.<lambda>(<Task finishe...ed_future'",)>) at C:\Users\******\lib\site-packages\tornado\web.py:2333
handle: <Handle _HandlerDelegate.execute.<locals>.<lambda>(<Task finishe...ed_future'",)>) at C:\Users\******\lib\site-packages\tornado\web.py:2333>
Traceback (most recent call last):
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1665, in _execute
    if self.request.method not in self.SUPPORTED_METHODS:
AttributeError: 'function' object has no attribute 'method'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\******\lib\asyncio\events.py", line 145, in _run
    self._callback(*self._args)
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 2333, in <lambda>
    fut.add_done_callback(lambda f: f.result())
  File "C:\Users\******\lib\site-packages\tornado\web.py", line 1714, in _execute
    if self._prepared_future is not None and not self._prepared_future.done():
AttributeError: 'defaultHandler' object has no attribute '_prepared_future'

我做错了什么？我找不到带有 python tornado 的 404 页面的任何示例。我查看了路由器，但这似乎不适合这里。

Answer 1

你不应该在不调用超类的 __init__ 方法的情况下覆盖 __init__。 RequestHandler.__init__ 有两个你必须传递的参数。出于这个原因，通常覆盖 RequestHandler.initialize 方法而不是 __init__。但是不清楚这个例子中的 arg2 和 arg3 是什么，所以我完全不确定你为什么要重写这个方法。

传统的 404 处理程序如下所示：

class DefaultHandler(RequestHandler):
    def prepare(self):
        # Use prepare() to handle all the HTTP methods
        self.set_status(404)
        self.finish("404 - my thing")

带有 Python 龙卷风的自定义 404 错误页面

Custom 404 Errorpage with Python tornado

python

tornado

traceback