On Tue, 2004-02-24 at 13:35, Phil Hunt wrote:

I am trying to get my head round Twisted, particularly to use it as a simple web server (using http as a RPC mechanism, really). I was thinknig of using a "Rosetta Stone" approach, and am wondering if someone could translate this ordinary Python program into Twisted, please:

Attached are two examples of what you've described, both of which are a lot easier on the eyes than SimpleHTTPServer code. rosetta1 just uses twisted.web's Resource object, which is relatively basic in its capabilities. If you want more scalable and flexible templating and web application design, you might want to start working with Nevow, which is what rosetta2 demonstrates. Both of these scripts should be run using the following command: $ twistd -ony rosettaX.tac.py Hope this helps. -- Alex Levy WWW: http://mesozoic.geecs.org "Never let your sense of morals prevent you from doing what is right." -- Salvor Hardin, Isaac Asimov's _Foundation_

Phil Hunt writes:

rosetta1 kind-of does what I want, but not quite, when I try to fetch the URL http://localhost:1450/xxx?aaa=bbb&c=12345 in my web browser, it says request.path = /xxx, whereas I'm interested in the variable/value pairs as well, i.e. /xxx?aaa=bbb&c=12345

Ah, yeah, that would be a difference between that and the simpler HTTP handler object in the standard library. The Twisted support code automatically parses out the arguments for you and makes them available from the request object (passed in to the render method in rosetta1) in the args attribute. It's a dictionary keyed by variable, with the value being a list of values supplied. The value is always a list even if only one instance of the variable occurs in the URL. So in your example here, in the render() method, request.args would be set to {'aaa':['bbb'],'c':['12345']}.

If I wrote a program like this that was invoked by the ``python'' program rather than ``twistd'', would that make a difference it what it can do?

Not particularly - you can pretty much do anything in either case, but the sequence of how to initialize things (and how much work you might need to do to accomplish a particular initialization) will differ. twistd provides some standard startup handling, but you can initialize things and run the reactor yourself if you want. For example, one way to have a more standalone version would be to replace the bottom portion of rosetta1 (starting from "application = " down) with: site = server.Site(resource=MyResource()) reactor.listenTCP(1450, site) reactor.run() and you'd need a "from twisted.internet import reactor" at the top (and could remove the application imports). It's not exactly identical since the application/service approach is initializing a more flexible framework, but for this example, the end result is the same. With the above change you could just run the script with Python. You can pretty much do anything you want at that point, although you need to get to the reactor.run() for most stuff to start running. You can also hang other services off of your application object and do other initialization in the twistd/tac case. I don't tend to use twistd that much myself, but I'm sure for others it's what they prefer. Oh, and if you'd like to see some simple logging of requests and what not you can just enable logging by: import sys from twisted.python import log at the top, and log.startLogging(sys.stdout) before creating your site. I think the equivalent is just a command line option with twistd. -- David