Porting to new Python version
Hi, I have a tough issue: we are using a Python application written quite a time ago for version 2.4. The code is mature, and there are no bugs. My bosses came up with the idea to port it to the latest release... I am not really convinced that it's a good step. I wellcome any information pro and contra. I would like to get the background as precisely as possible. Thanks in advance and good day to You! Gabor -- http://mail.python.org/mailman/listinfo/python-list
Re: Porting to new Python version
On Feb 19, 5:50 pm, Gabor Urban urbang...@gmail.com wrote: Hi, I have a tough issue: we are using a Python application written quite a time ago for version 2.4. The code is mature, and there are no bugs. My bosses came up with the idea to port it to the latest release... I am not really convinced that it's a good step. I wellcome any information pro and contra. I would like to get the background as precisely as possible. Thanks in advance and good day to You! Gabor It might be helpful if you can provide more information regarding your application. For example, does it use lot of 3rd party code, What is the reason behind porting to latest version etc. All said, 2.4 to 2.5 or even 2.6 should not be much of an issue - it even has the advantage that performance is improved and some memory leaks are no longer there. Python 3* should be a problem since many 3rd party applications are not yet ported to it. -- http://mail.python.org/mailman/listinfo/python-list
Re: Porting to new Python version
i don't know what the context is, so it's hard for me to comment on the decision (i assume there are commerical pressures like customers not wanting to install old versions). however,if you go ahead, you need to think about exactly what you want to target. the latest version is really 3.0.1. moving to 3 is probably not that hard (and there are tools to automate the process). also, 2.6 is largely compatible with 3. so moving to something that works with 2.6 and 3 is probably a reasonable target. but that code will not work, without more significant effort, on 2.5 and earlier. so one idea would be to keep your existing code for 2.4, and update for 3. for some time (years) you will need to support two versions, but if it is stable then that may not be much work. alternatively, you could ignore 3, which is not going to be mainstream for some time, and simply run against 2.6 and 2.5. that should be even less work because you're staying with 2. you could then say that your code works on 2.4 through 2.6 or, finally, you could do the second step above (to get code that works on 2.4 to 2.6) and then the first step (to get a separate version that works on 3). doing things in that order (with staged releases) lets you get most bug fixes for 2.5/6 into the code before branching for 3. hope that makes sense. disclaimer - i have not done the above; this is from reading various newsgroups and attempting to backport a project written in 3 to 2 (it was easy to go to 2.6, but i failed to get the same code to run on 2.5). andrew Gabor Urban wrote: Hi, I have a tough issue: we are using a Python application written quite a time ago for version 2.4. The code is mature, and there are no bugs. My bosses came up with the idea to port it to the latest release... I am not really convinced that it's a good step. I wellcome any information pro and contra. I would like to get the background as precisely as possible. Thanks in advance and good day to You! Gabor -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Porting to new Python version
Gabor Urban wrote: Hi, I have a tough issue: we are using a Python application written quite a time ago for version 2.4. The code is mature, and there are no bugs. My bosses came up with the idea to port it to the latest release... I am not really convinced that it's a good step. I wellcome any information pro and contra. I would like to get the background as precisely as possible. Thanks in advance and good day to You! As long as you don't plan to migrate to 3.0 you may well be surprised at how easy the port is. Python's backwards compatibility has been pretty good. Moving to 3.0 will demand more thought and testing. One might ask what the advantages are supposed to be, of course, but generally bosses aren't interested in explaining themselves ... regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Porting to new Python version
maybe i should clarify that easy below is going to be relative. the process may end up being very hard due to various other reasons. what i was trying to explain is that (1) 3 is probably going to require a separate branch from 2; (2) that 2.6 and 3 can both be considered latest; (3) moving from 2.4 to 2.6 is probably best done before branching for 3; (4) moving from 2.4 to 2.6 is probably easier than moving from 2 to 3. andrew andrew cooke wrote: i don't know what the context is, so it's hard for me to comment on the decision (i assume there are commerical pressures like customers not wanting to install old versions). however,if you go ahead, you need to think about exactly what you want to target. the latest version is really 3.0.1. moving to 3 is probably not that hard (and there are tools to automate the process). also, 2.6 is largely compatible with 3. so moving to something that works with 2.6 and 3 is probably a reasonable target. but that code will not work, without more significant effort, on 2.5 and earlier. so one idea would be to keep your existing code for 2.4, and update for 3. for some time (years) you will need to support two versions, but if it is stable then that may not be much work. alternatively, you could ignore 3, which is not going to be mainstream for some time, and simply run against 2.6 and 2.5. that should be even less work because you're staying with 2. you could then say that your code works on 2.4 through 2.6 or, finally, you could do the second step above (to get code that works on 2.4 to 2.6) and then the first step (to get a separate version that works on 3). doing things in that order (with staged releases) lets you get most bug fixes for 2.5/6 into the code before branching for 3. hope that makes sense. disclaimer - i have not done the above; this is from reading various newsgroups and attempting to backport a project written in 3 to 2 (it was easy to go to 2.6, but i failed to get the same code to run on 2.5). andrew Gabor Urban wrote: Hi, I have a tough issue: we are using a Python application written quite a time ago for version 2.4. The code is mature, and there are no bugs. My bosses came up with the idea to port it to the latest release... I am not really convinced that it's a good step. I wellcome any information pro and contra. I would like to get the background as precisely as possible. Thanks in advance and good day to You! Gabor -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Porting to new Python version
On Feb 19, 1:50 pm, Gabor Urban urbang...@gmail.com wrote: Hi, I have a tough issue: we are using a Python application written quite a time ago for version 2.4. The code is mature, and there are no bugs. My bosses came up with the idea to port it to the latest release... I am not really convinced that it's a good step. I wellcome any information pro and contra. I would like to get the background as precisely as possible. Thanks in advance and good day to You! Gabor I am a fan of smooth upgrades. Just move to Python 2.5 and you should have little troubles. You can wait one year or so for Python 2.6. As a rule of thumb, I think it is safe to upgrade to a newer Python versions after one year from its first release, to give time to third party packages. There are of course exceptions. For instance I remember Zope being far behind Python releases. I have currently a Zope application running in Python 2.4 that I cannot upgrade. It all depends from your external dependencies. If you do not have any, and you do not anticipate the need for any, you can probably upgrade to Python 2.6 with no effort. Michele Simionato -- http://mail.python.org/mailman/listinfo/python-list
