tornado.wsgi.WSGIApplication 问题：__call__ 正好需要 3 个参数（给定 2 个）

Question

作为项目的一部分，我一直在尝试移植 Tornado 服务器以在 Google App Engine 上工作。由于 App Engine 没有实现普通 Tornado 的异步功能，所以我一直在尝试将主应用程序转换为 WSGIApplication。正常的主代码工作正常（原谅导入和格式化，尝试遵循其他示例会一团糟）：

import wsgiref
import tornado.wsgi
import tornado.web
import tornado.httpserver
import os
import Handlers
from tornado.options import define, options

define("port", default=8000, help="run on the given port", type=int)

def application():
    handlers=[(r"/", Handlers.MainHandler),
            (r"/Login", Handlers.LoginHandler),
            (r"/ViewHistory",Handlers.ViewHistoryHandler),
            (r"/UploadFile", Handlers.UploadHandler),
            (r"/Index", Handlers.IndexHandler),
            (r"/About", Handlers.AboutHandler),
            (r"/Profile", Handlers.ProfileHandler)]

    settings=dict(template_path=os.path.join(os.path.dirname(__file__), "templates"),
                static_path=os.path.join(os.path.dirname(__file__), "static"),
                debug=True)

    return tornado.web.Application(handlers, **settings)

def main():
    tornado.options.parse_command_line()
    http_server = tornado.httpserver.HTTPServer(application())
    http_server.listen(options.port)
    tornado.ioloop.IOLoop.instance().start()

if __name__ == "__main__":
    main()

我可以访问网页，浏览网站，效果很好。如果我将第 24 行更改为返回 tornado.wsgi.WSGIApplication，如下所示：

import wsgiref
import tornado.wsgi
import tornado.web
import tornado.httpserver
import os
import Handlers
from tornado.options import define, options

define("port", default=8000, help="run on the given port", type=int)

def application():
    handlers=[(r"/", Handlers.MainHandler),
            (r"/Login", Handlers.LoginHandler),
            (r"/ViewHistory",Handlers.ViewHistoryHandler),
            (r"/UploadFile", Handlers.UploadHandler),
            (r"/Index", Handlers.IndexHandler),
            (r"/About", Handlers.AboutHandler),
            (r"/Profile", Handlers.ProfileHandler)]

    settings=dict(template_path=os.path.join(os.path.dirname(__file__), "templates"),
                static_path=os.path.join(os.path.dirname(__file__), "static"),
                debug=True)

    return tornado.wsgi.WSGIApplication(handlers, **settings)

def main():
    tornado.options.parse_command_line()
    http_server = tornado.httpserver.HTTPServer(application())
    http_server.listen(options.port)
    tornado.ioloop.IOLoop.instance().start()

if __name__ == "__main__":
    main()

它也运行得很好。但是，当我尝试访问任何网页时，都会出现以下错误：

[E 140131 10:02:18 iostream:357] Uncaught exception, closing connection.
    Traceback (most recent call last):
      File "/usr/local/lib/python2.7/dist-packages/tornado-3.2-py2.7-linux-x86_64.egg/tornado/iostream.py", line 354, in wrapper
        callback(*args)
      File "/usr/local/lib/python2.7/dist-packages/tornado-3.2-py2.7-linux-x86_64.egg/tornado/stack_context.py", line 331, in wrapped
        raise_exc_info(exc)
      File "/usr/local/lib/python2.7/dist-packages/tornado-3.2-py2.7-linux-x86_64.egg/tornado/stack_context.py", line 302, in wrapped
        ret = fn(*args, **kwargs)
      File "/usr/local/lib/python2.7/dist-packages/tornado-3.2-py2.7-linux-x86_64.egg/tornado/httpserver.py", line 328, in _on_headers
        self.request_callback(self._request)
    TypeError: __call__() takes exactly 3 arguments (2 given)
[E 140131 10:02:18 ioloop:491] Exception in callback <functools.partial object at 0xf6e3ecfc>
    Traceback (most recent call last):
      File "/usr/local/lib/python2.7/dist-packages/tornado-3.2-py2.7-linux-x86_64.egg/tornado/ioloop.py", line 477, in _run_callback
        callback()
      File "/usr/local/lib/python2.7/dist-packages/tornado-3.2-py2.7-linux-x86_64.egg/tornado/stack_context.py", line 331, in wrapped
        raise_exc_info(exc)
      File "/usr/local/lib/python2.7/dist-packages/tornado-3.2-py2.7-linux-x86_64.egg/tornado/stack_context.py", line 302, in wrapped
        ret = fn(*args, **kwargs)
      File "/usr/local/lib/python2.7/dist-packages/tornado-3.2-py2.7-linux-x86_64.egg/tornado/iostream.py", line 354, in wrapper
        callback(*args)
      File "/usr/local/lib/python2.7/dist-packages/tornado-3.2-py2.7-linux-x86_64.egg/tornado/stack_context.py", line 331, in wrapped
        raise_exc_info(exc)
      File "/usr/local/lib/python2.7/dist-packages/tornado-3.2-py2.7-linux-x86_64.egg/tornado/stack_context.py", line 302, in wrapped
        ret = fn(*args, **kwargs)
      File "/usr/local/lib/python2.7/dist-packages/tornado-3.2-py2.7-linux-x86_64.egg/tornado/httpserver.py", line 328, in _on_headers
        self.request_callback(self._request)
    TypeError: __call__() takes exactly 3 arguments (2 given)

我无法确定这一点，而且 Google 还没有发现任何有同样问题的人（除了建议在 Tornado 文件中乱搞的人，这对 App Engine AFAIK 没有帮助）。有没有其他人以前见过这个错误，或者可以发现为什么 WSGIApplication 在默认应用程序没有崩溃时崩溃？

Answer 1

不幸的是，“应用程序”这个名字在这里被重载了——tornado.web.Application 和 WSGIApplication 在它们与服务器的接口上有所不同。 tornado.web.Application 可以被 tornado HTTPServer 使用，但是 WSGIApplication 必须在 WSGI 容器中运行。在应用引擎部署中，您只需在配置文件中直接提及您的 WSGIApplication 实例，而不提及 tornado.httpserver。要使用将 WSGIApplication 适配到 tornado.httpserver，请使用 tornado.wsgi.WSGIContainer：HTTPServer(WSGIContainer(application()))