tornado | 易学教程

Python Errno 9 Bad file descriptor in Mac OS X

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问题 I have the following code running without any problem multiple times after each other in Linux: def test_ftp(ftpserver): with FTP() as f: f.connect("localhost", port=ftpserver.server_port) f.login("M1", "bachmann") f.cwd("/") f.mkd("FOO") f.quit() The same tests can only be run once in MacOS X, after that it will simply hang. Rebooting the machines, is the only way I can re-run the tests. ftpserver is a test fixture defined in pytest-localftpserver, I am posting the code for this fixture here

how do twisted/tornado et cetera work

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问题 I understand that they work in some way distinct from making a thread per user. How exactly does that work? (Does 'non-blocking' have something to do with it?) 回答1: From the Twisted documentation: The reactor is the core of the event loop within Twisted -- the loop which drives applications using Twisted. The event loop is a programming construct that waits for and dispatches events or messages in a program. It works by calling some internal or external "event provider", which generally

How do I send a websocket message in Tornado at will?

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问题 I'm very new to Tornado and wanted to know if it is possible to send a message (write_message) at will from within my Python program to all clients? For example, say my program is monitoring a directory to see if a file appears/exists. When it appears, I want to send a web socket message to a browser client that the file exists. I can't seem to understand how to invoke the "write_message" method without first receiving a websocket message (on_message handler.) Even if I use the

Python3.8安装 jupyter报错 NotImplementedError

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报错如下：原因：是由于 python3.8 asyncio 在 windows 上默认使用 ProactorEventLoop 造成的，而不是之前的 SelectorEventLoop。jupyter 依赖 tornado，而 tornado 在 window 上需要使用 SelectorEventLoop，所以产生这个报错。 On Windows, Tornado requires the ``WindowsSelectorEventLoop``. This is the default in Python 3.7 and older, but Python 3.8 defaults to an event loop that is not compatible with Tornado. Applications that use Tornado on Windows with Python 3.8 must call ``asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())`` at the beginning of their ``main`` file/function. 而对于像 jupyter 这种依赖于 tornado 的库，则无法用这种方式。目前这个问题已由 python

Why isn't this Jinja2 template rendering faster than Djangos?

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问题 I was curious to see how much faster Jinja2 (2.6) was than the stock Django (1.3.1) template engine. Running it I get: Django: 275.729 ms per iteration Jinja2: 281.190 ms per iteration (the smaller the better) Here's the Django benchmark: http://hastebin.com/DyGcxEybYd.py Here's the Jinja2 benchmark: http://hastebin.com/uorDENWrkM.py For a reference, the same Tornado template test manages to do it in 28.127 ms per iteration which is about 10 times faster which is almost too good to be true.

Is it possible to send a message to all active WebSocket connections? Using either node.js or python tornado websockets

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问题 I'm experimenting with building a websocket's based application. I am wondering whether it's possible to send a message to all active connections as they are persistant. Say I'm running a live auction site and I have multiple users watching the auction page, each of them is connected via sockets to my server. Now let's say one user raises the bid. I want to send a message to all connected clients. Easiest way is to have the clients poll the server via socket every second, but I think the idea

Python BaseHTTPServer and Tornado

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问题 I'm running a BaseHTTPServer, passed through ThreadedHTTPServer so I get threading. server = ThreadedHTTPServer(('', int(port)), MainHandler) Next I fork according to the info here: Daemonizing python's BaseHTTPServer Then I do: server.serve_forever() What I am trying to do is have the same Python script run a Tornado WebSocket server as well, I tried creating the second handler and in my main creating the second server similar to above, but then the serve_forever() blocks (I assume) and I

Tornado POST 405: Method Not Allowed

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问题 For some reason, I am not able to use post methods in torando. Even the hello_world example does not work when I change get to post. import tornado.ioloop import tornado.web class MainHandler(tornado.web.RequestHandler): def post(self): self.write("Hello, world") application = tornado.web.Application([ (r"/", MainHandler), ]) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start() It throws 405 method not allowed. Any suggestions ? 回答1: You still need get

send multiple async post request with tornado

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问题 there are several questions on stackoverflow regarding tornado I still haven't found out an answer to my question I have a big text file that I wish to iterate on and send each line as a POST http request. I wish to do it async ( I need it to be fast) and then check the responses of the requests. I have something like that http_client = httpclient.AsyncHTTPClient() with open(filename) as log_file: for line in log_file: request = httpclient.HTTPRequest(self.destination,method="POST",headers

Standalone Python web server and/or nginx

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问题 So I've done some reading about Python web frameworks (or servers?), mostly Tornado and Bottle but also FAPWS3, and there are still some grey areas. First, these three web frameworks are all said to be fast, yet they all include a web server written in Python (except FAPWS3) which should be put behind nginx/Apache. Isn't this reducing the performance? I mean, we know that Python is much slower than C, why not only use nginx, or at worst, only the included Python web server? 回答1: First of,