On 3/5/07, Facundo Batista <[EMAIL PROTECTED]> wrote: > Thomas Wouters wrote: > > > developers and people who develop their own software. I would like to hear > > from people who have concrete doubts about this upgrade path. I don't mean > > Disclaimer: I'm not involved in Py3k, and not even tried it once. And > don't know the details of the tool to "transform" Py2 to Py3. > > Having said that, the *only* fear I have, is how safe it will be. And > here comes the explanation. > > I'm now in an enviroment where we rely on Python, and I advocates on it > everyday. We use 2.3, and 2.4, some servers we're about to deploy have > 2.5, and we'll use the lastest Py2.x everytime we deploy a new machine. > > But, as we have always running behind our ToDo, we don't have time to > say "Ok, this server runs 2.3, how can I start using 2.5?". Too many > servers, too many applications, too many > undocumented-and-nobody-knows-about-it applications. And they all are > applications running 7x24.
I know the feeling. Google still uses Python 2.2 for most apps. We're supporting 2.4 as well, and hope to have the last apps migrated to 2.4 in a year or so. *Then* we'll start supporting a higher version -- probably 2.6 by then. > And Py3k is around the corner, and I even heard some guys saying "If I'd > spent time taking care that this app runs ok after changing a bit of > it, I'll wait to Python 3000". In your kind of env it's clearly too early to think about 3.0. You shouldn't expect to be switching until a year after 3.0 is released, probably. > So, the enviroment is explained, now I go with "how safe it will be". > I'd love to know that there'll be a tool that tells me, after running it > over my application, Your app is "ready for migration"'. I do *not* care > if it takes a lot of work to make the proper changes, but I need to feel > confident that after running the last changed version during a week in, > say, Py2.7, and no warnings appear, and the "verification tool" say > green light, I can start running it in Py3k. And look at it a week more. > And say "life is great", :) You need comperhensive unit tests too. Then: *If* you get the green light from 2.6's py3k warning mode, *and* the conversion tool produces syntactically correct code without issuing warnings, *and* your unit tests all pass, *then* I expect you'll be in about the same situation as for any version upgrade in such an environment (e.g. 2.4 -> 2.5). I.e. you need to do a big integration test and once that passes you should be set for a stress-free transition. I think that's the best we can hope for. I plan to do it this way at Google too. > Anyway, I know how hard is it, and I regret not having the time I'd love > to have to help you. All I can do is thank you. > > Thank you very much! You're welcome! > > One thing in particular I wonder about is the warning about mixing tabs and > > spaces. Should it be in category 2) (on by default) or 3) (still off by > > default, but part of -Wpy3k)? > > For me, I'd love to 2.6 start warning "you're mixing tab and spaces, > shame yourself!". (The English say "shame on you" :-) While I'd like to do this too I don't know how many folks there are out there who have no way to suppress the warning (because they're end users of a script someone else wrote for them). I think it may be more of a development warning, so I think category is appropriate. -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
