Re: Decoupling the version of the file from the name of the module.
[EMAIL PROTECTED]
I'm a newbie experimenting with Python. I want to incrementally develop
a module called 'circle'.
. . .
Basically I want to decouple the version of my file from the name of
the module.
Is there a *simple* way out of this dilemma.
In the client code, use an import/as statement and update that single
line as needed:
import circle_b as circle
If you don't want to edit the client code every time, the import can be
automated to smartly find the most recently updated version. Build a
list of filenames using your naming convention. Sort them by
modification date. Then, import the most recent one as circle:
names = glob.glob('circle_*.py')
names.sort(key=lambda f: os.stat(f).st_mtime)
newest_name = names[-1]
newest_module, ext = os.path.splitext(newest_name)
circle = __import__(newest_module)
Of course, the right answer is to do what everyone else does. Use a
version control system instead of multiple files.
Raymond
--
http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
On Sun, 29 Jan 2006 00:07:29 -0800, Raymond Hettinger wrote: [EMAIL PROTECTED] I'm a newbie experimenting with Python. I want to incrementally develop a module called 'circle'. . . . Basically I want to decouple the version of my file from the name of the module. Is there a *simple* way out of this dilemma. [snip] Of course, the right answer is to do what everyone else does. Use a version control system instead of multiple files. Which is the right answer to a question, but I'm not convinced it is the right answer to the implied question. For serious development, version control systems are the way to go. No arguments from me, we agree. But CVS or similar doesn't help you when you are *distributing* your modules to others. I fear I'm belabouring the obvious, but in case it isn't obvious what I mean, here is a made-up example: I distribute two apps, Parrot and Shrubbery. Both rely on a common module, Spam. Parrot uses version 1 of Spam and Shrubbery uses version 2. For the sake of the argument, Spam is completely backwards compatible, so I have no problems with somebody installing Parrot plus Spam version 1, then installing Shrubbery, where Spam version 2 overwrites the older Spam module. But if Spam version 1 overwrites version 2, then Shrubbery stops working. The easy answer is to say, Then don't do that, but that's a terribly impractical answer. Blaming the user is no real solution either. In old-time Windows land, installation programs would blindly nuke newer DLLs with older DLLs all the time. Under Linux, one convention is for shared libraries to include the version number in the file name, so that newer libraries weren't blown away by older ones. What is the Python solution? Enquiring minds want to know. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
[EMAIL PROTECTED] wrote: Now suppose I have make a new version with __version__ = 1.1. What shall I call this file and (I don't want to overwrite the old file if I need to go back to it) how do I import it from the shell. Your advice sounds nice, but I would appreciate if you could give me (or point me to) a simple example. Thanks As Kirk, Roy and Peter suggested (nay, commanded), use a versioning system, either CVS or Subversion for example (both are quite simple, Subversion has a 1 click installer for Windows boxes, and there is a small book/user manual with it so that you're not lost), they'll do what you need (keep the old versions around just in case) and much more to boot. Spending a day or two learning about how the versioning system you'll have chosen work is an investment that you'll get back tenfold in no time, so don't get intimidated or scared. -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
Steven D'Aprano wrote: I distribute two apps, Parrot and Shrubbery. Both rely on a common module, Spam. Parrot uses version 1 of Spam and Shrubbery uses version 2. For the sake of the argument, Spam is completely backwards compatible, so I have no problems with somebody installing Parrot plus Spam version 1, then installing Shrubbery, where Spam version 2 overwrites the older Spam module. But if Spam version 1 overwrites version 2, then Shrubbery stops working. The easy answer is to say, Then don't do that, but that's a terribly impractical answer. Blaming the user is no real solution either. In old-time Windows land, installation programs would blindly nuke newer DLLs with older DLLs all the time. Under Linux, one convention is for shared libraries to include the version number in the file name, so that newer libraries weren't blown away by older ones. What is the Python solution? Enquiring minds want to know. http://peak.telecommunity.com/DevCenter/PythonEggs http://peak.telecommunity.com/DevCenter/PkgResources -- Robert Kern [EMAIL PROTECTED] In the fields of hell where the grass grows high Are the graves of dreams allowed to die. -- Richard Harter -- http://mail.python.org/mailman/listinfo/python-list
Decoupling the version of the file from the name of the module.
I'm a newbie experimenting with Python. I want to incrementally develop a module called 'circle'. The problem is now that the file name is used for two purposes. To keep track of the version number and as the name for the module. So when I develop the first version of my file I have to call it circle_a.py. The name of the module then automatically becomes circle_a. But when I develop the next increment and call my file circle_b.py the module name changes as well. Basically I want to decouple the version of my file from the name of the module. Is there a *simple* way out of this dilemma. -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
[EMAIL PROTECTED] wrote: I'm a newbie experimenting with Python. I want to incrementally develop a module called 'circle'. The problem is now that the file name is used for two purposes. To keep track of the version number and as the name for the module. So when I develop the first version of my file I have to call it circle_a.py. The name of the module then automatically becomes circle_a. But when I develop the next increment and call my file circle_b.py the module name changes as well. Basically I want to decouple the version of my file from the name of the module. Is there a *simple* way out of this dilemma. You have two choices: 1- Just get rid of the version number in the name (what's the point) and define a __version__ attribute in the module, that's what is usually done. 2- create a wrapper module called circle.py whose content will be something along the lines of from your_current_module_with_version import * I'd strongly suggest the first choice, there is no point in giving the version number into the file name of a module. -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
[EMAIL PROTECTED] wrote: I'm a newbie experimenting with Python. I want to incrementally develop a module called 'circle'. The problem is now that the file name is used for two purposes. To keep track of the version number and as the name for the module. So when I develop the first version of my file I have to call it circle_a.py. The name of the module then automatically becomes circle_a. But when I develop the next increment and call my file circle_b.py the module name changes as well. Basically I want to decouple the version of my file from the name of the module. Is there a *simple* way out of this dilemma. I would recommend just naming the file circle.py, and defining something like a variable named __version__ or maybe __revision__ at the top of the module. Then you can, I don't know, back up your old versions to other filenames or something. Or, if you really want to do this right, you could install Subversion. :-) -Kirk McDonald -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
[EMAIL PROTECTED] writes: Basically I want to decouple the version of my file from the name of the module. Is there a *simple* way out of this dilemma. Really, you should use a source control system. That's a program that tracks the different versions of the files in your program. When one of your files reaches a state of stability, you check it in to a source repository which then remembers that version. You then go on editing the file in place. Later, you can restore the old version from the repository if you need to. Source control is the only sane way to do what you're trying to do. Messing around with renaming files to save old versions, as you're doing, only works for very small, short-lived projects. That scheme will drive you crazy in short order. SubVersion (http://subversion.tigris.org) is a popular source control system, maybe not the best, but compatible with some older widely used ones. I'd personally choose this one because I have some experience with it, but it's not ideal. Even if you don't choose to use it, you might read its online docs, to get a sense of what kinds of problems these programs try to solve. There's a newer one called Codeville, written in Python, that I haven't tried. There are numerous others I won't bother trying to list. Which one is best is the topic of religious wars, like the best editor or the best language. Just pick one that you like and stick with it. -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
Xavier Morel wrote: Just get rid of the version number in the name (what's the point) and define a __version__ attribute in the module, that's what is usually done. Thanks Xavier, but as I said I'm newbie and I'm not sure how to do that. Here's my module # circle.py from math import pi __version__ = '1.0' def disk(r): Returns the area of the disk with radius r. return (pi * r**2) def test(): print disk(1) print disk(2) # end of the module Now suppose I have make a new version with __version__ = 1.1. What shall I call this file and (I don't want to overwrite the old file if I need to go back to it) how do I import it from the shell. Your advice sounds nice, but I would appreciate if you could give me (or point me to) a simple example. Thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
In article [EMAIL PROTECTED], [EMAIL PROTECTED] wrote: I'm a newbie experimenting with Python. I want to incrementally develop a module called 'circle'. The problem is now that the file name is used for two purposes. To keep track of the version number and as the name for the module. So when I develop the first version of my file I have to call it circle_a.py. The name of the module then automatically becomes circle_a. But when I develop the next increment and call my file circle_b.py the module name changes as well. Basically I want to decouple the version of my file from the name of the module. Is there a *simple* way out of this dilemma. Why do you have to change the name of the file each time you come out with a new version? I think that's where you're going wrong. Put something *inside* the file to indicated the version number, but keep the name of the file the same. -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
On Sat, 28 Jan 2006 23:13:12 +0100, Xavier Morel wrote: [EMAIL PROTECTED] wrote: I'm a newbie experimenting with Python. I want to incrementally develop a module called 'circle'. The problem is now that the file name is used for two purposes. To keep track of the version number and as the name for the module. So when I develop the first version of my file I have to call it circle_a.py. The name of the module then automatically becomes circle_a. But when I develop the next increment and call my file circle_b.py the module name changes as well. Basically I want to decouple the version of my file from the name of the module. Is there a *simple* way out of this dilemma. You have two choices: 1- Just get rid of the version number in the name (what's the point) and define a __version__ attribute in the module, that's what is usually done. 2- create a wrapper module called circle.py whose content will be something along the lines of from your_current_module_with_version import * I'd strongly suggest the first choice, there is no point in giving the version number into the file name of a module. Modules are conceptually like a shared code library, and remember the awful problem of DLL hell on Windows? In Linux land, the convention is that libraries have the version number in the file name, so that when you install a library, it doesn't overwrite any pre-existing versions of the library. This is a Good Thing. I haven't been distributing a large number of Python applications to outsiders, so I don't know how much of a practical problem it is for Python, but if you have a rapidly changing module, with changes to the API, this is certainly a theoretical problem, if not a practical one. If it is not a problem in practice, why not? What do people do to avoid this? -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
[EMAIL PROTECTED] wrote: Now suppose I have make a new version with __version__ = 1.1. What shall I call this file and (I don't want to overwrite the old file if I need to go back to it)? Stop everything right now and get yourself some kind of version control system. CVS (http://ximbiot.com/cvs/wiki/index.php?title=Main_Page) is a popular one. Subversion (http://subversion.tigris.org/) is a bit newer, and quickly gaining is popularity. If some other system (Perforce, ClearCase, RCS, SCCS, etc) is already in use where you are, just use that. Many IDEs come with something built-in. Which one you pick is a detail, but it's essential that you use something. If you don't use some kind of version control system, you end up mired in thorny questions like the one you ask above. Learning something like cvs may seem intimidating at first, but believe me, it's impossible to do any kind of serious software development without one. -- http://mail.python.org/mailman/listinfo/python-list
Re: Decoupling the version of the file from the name of the module.
Roy Smith wrote: [EMAIL PROTECTED] wrote: Now suppose I have make a new version with __version__ = 1.1. What shall I call this file and (I don't want to overwrite the old file if I need to go back to it)? Stop everything right now and get yourself some kind of version control system. CVS (http://ximbiot.com/cvs/wiki/index.php?title=Main_Page) is a popular one. Subversion (http://subversion.tigris.org/) is a bit newer, and quickly gaining is popularity. Listen to Roy. Get a source code control system. Use any one you want, provided that if your choice is between CVS and Subversion, you use Subversion. ;-) -Peter -- http://mail.python.org/mailman/listinfo/python-list
