Tarek Ziadé wrote: > On Wed, Oct 21, 2009 at 10:42 AM, M.-A. Lemburg <m...@egenix.com> wrote: >> Tarek Ziadé wrote: >>> On Tue, Oct 20, 2009 at 5:20 PM, M.-A. Lemburg <m...@egenix.com> wrote: >>>>>> The micro-language should provide a limited number of >>>>>> variables to use on the conditions: >>>>>> >>>>>> python_version = sys.version >>>>>> sys_platform = sys.platform >>>>> >>>>> If we adopt such a micro-language (I'm reserving judgment until I've >>>>> had more time to read the relevant PEPs carefully), I'd rather see the >>>>> names match what's in the Python runtime more closely, probably only >>>>> avoiding the call syntax. >>>> >>>> We could do that as well, yes. >>> >>> +1 on close names + no call syntax >>> >>> but, notice that "python_version" here is: "%s.%s" % >>> sys.version_info[0], sys.version_info[1] >>> >>> thats why we came up with that name, to disinguish it from sys.version >>> (that contains more stuff) >> >> I think we do need the full version here, so perhaps using >> sys.version.split()[0] would be better or simply the full >> version string and then have conditions use >=, <=, <, > >> only (ie. not =, since that would likely never match). > > Notice that for the comparisons >, < to work, that requires more than string > comparisons in case we provide the ability to work with rc versions, because: > >>>> '2.6.3rc4' < '2.6.3' > False > > We said earlier that we could use sys.hexversion to handle this, but > otherwise, > at least for the Python version, we can use the StrictVersion() class > from Distutils, > > *But* we ended up thinking that it would be better for the first version to > keep > just "==", "!=", "in" and "not in" operators and a MAJOR.MINOR string. > > These are enough just to compare strings, on a limited number of > versions for Python.
Ok. > What use case you have in mind for a three numbers version ? This may occur when you for example rely on PyXML, elementtree or simplejson which are also available as external packages (with a different release cycle). E.g. say there's a bug in the JSON package included in Python versions 2.6.0, 2.6.1, 2.6.2 which is fixed in 2.6.3 and has also been fixed in the PyPI version of the package. Now say that a system ships with 2.6.1 as Python version. For Python versions with the bug, you'd add a requirement for the external package in order to work around the bug in the system installation of Python. For Python versions >= 2.6.3, you'd continue to use the package from the system provided Python installation. It's a rather rare use case, so just something to think about for a future revision of the proposal. >> Note that packages do sometimes need to know that a certain >> Python patch level release is installed (e.g. Zope often has >> had this need) and a proper dependency checker would have to >> detect a possible mismatch. > > I see. I would rather have this patch info in another variable, and restrict > the micro language capabilities as much as possible. > > Any hint were Zope does this ? Early Zope versions simply warned about the problem in the release documentation. IIRC, later versions actually tested the installed Python version and warned about issues during the installation process. I'm not sure how Zope 2.12 with all the tiny little packages handles this case. -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Oct 21 2009) >>> Python/Zope Consulting and Support ... http://www.egenix.com/ >>> mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ >>> mxODBC, mxDateTime, mxTextTools ... http://python.egenix.com/ ________________________________________________________________________ ::: Try our new mxODBC.Connect Python Database Interface for free ! :::: eGenix.com Software, Skills and Services GmbH Pastor-Loeh-Str.48 D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg Registered at Amtsgericht Duesseldorf: HRB 46611 http://www.egenix.com/company/contact/ _______________________________________________ Distutils-SIG maillist - Distutils-SIG@python.org http://mail.python.org/mailman/listinfo/distutils-sig
