take a look at the kedpm PKGBUILD [1], the package have /usr/bin/python as shebang, but if you run: python2 setup.py the script will automatically fix the shebangs to /usr/bin/python2 before installing ** [1] https://aur.archlinux.org/packages/ke/kedpm/PKGBUILD On Fri, Dec 16, 2011 at 5:30 AM, C Anthony Risinger <anthony@xxxxxxx> wrote: > On Thu, Dec 15, 2011 at 9:51 AM, Alex Bolgarov <alex@xxxxxxxxxxxx> wrote: >>> you all think the proper fix is for >>> me to put in the docs something like "on Arch systems you need to do >>> [x] before building", whether [x] is "get the PKGBUILD with the patch >>> from AUR" or even "run the sed-python-with-python2.sh included in the >>> distribution". >> >> I personally don't think it is a proper fix - I think it is not a fix >> at all. My opinion is that Python3 is sufficiently different from >> Python2 to be considered a new language, not just a new version of old >> (thus it would be appropriate to use new name, 'python3', for it, >> leaving 'python' forever referring to python2). (That is, desire to be >> on the bleeding edge does not warrant breaking existing software) > > http://mail.python.org/pipermail/python-dev/2011-March/108562.html > > ... the thread starts here: > > http://mail.python.org/pipermail/python-dev/2011-March/108491.html > > ... if it hasn't been linked already. that discussion led to the > aforementioned PEP, and was generally well-received (hence creation of > the PEP). > >> If I were you, I would probably stop putting shebangs into my Python >> scripts (so that they would be not executables), and write a shell >> wrapper script for every python script that figures out during runtime >> how python2 executable is called, and call python2 script using this >> python executables (or write single script with symbolic links to it >> with different names and use $0 shell variable to find which python >> script to call). > > you can factor out pieces into separate files and selectively import > based on various criteria, like any other module. create an small > bootstrap file that is python2/3 compatible and either run/import > according to the binary you're running under, or re-exec under a > different one (slightly rude form a user's perspective, but possible). > > a little funky, but you can test syntax using eval: > > http://stackoverflow.com/questions/446052/python-best-way-to-check-for-python-version-in-program-that-uses-new-language-f/446061#446061 > > ... and catch SyntaxError. > > per: > > http://mail.python.org/pipermail/python-dev/2011-March/108495.html > http://mail.python.org/pipermail/python-dev/2011-March/108499.html > > ... not sure if that's changed, but Arch isn't alone ... there was an > incubation period of a couple years, until 3.2 release, for > applications/libraries to catch up. python3 is here now, so let's > give her a big welcome, and move on ;-) > > -- > > C Anthony
