On 01/24/2015 05:27 AM, 杨令 wrote: >> From: Chi Hsuan Yen <yan12125@xxxxxxxxx> >> To: General Discussion about Arch Linux <arch-general@xxxxxxxxxxxxx> >> Cc: >> Date: Fri, 23 Jan 2015 21:51:00 +0800 >> Subject: [arch-general] An archlinux-python package for managing system > default python version? >> Dear Arch enthusiasts, >> >> The package extra/java-runtime-common provides a convenient script >> archlinux-java to handle co-existing JDK/JRE versions. I can use it to >> switch between different versions of java implementations to accomplish >> numerous tasks from testing the compatibilities of my programs to running >> third party applications targeting on different platforms. Now I hope >> there's also a simple script for the same thing but for python. On the >> system, most of the scripts are written for python2 and some other scripts >> are python3-specific. In most cases it's not a problem because I can fix >> the scripts or use some tricks like $PATH to ensure the correct execution >> of the programs. However, in large projects, doing either is > time-consuming >> and costly. Recently I'm building CyanogenMod on Arch Linux. It includes >> lots of python scripts in the build system, and most of them requires >> python2. Using the tip provided on the article about Python on ArchWiki >> prevents lots of problems, but, however, some scripts have the shebang > line >> "#!/usr/bin/env python" or are invoked by some command like >> "/usr/bin/python ...". I have to change the link /usr/bin/python to >> pointing to python2 for further progress on building and changed it back >> for my daily use. If there's an archlinux-python script, lots of time on >> battling the difference between python2 and python3 does not exist > anymore, >> which I believe lots of users can benefit from it. Any ideas? > > sudo pacman -S python-virtualenv python2-virtualenv python-virtualenvwrapper > > Google how to use them. > > Actually virtualenv itself is enough. virtualenvwrapper is a useful > wrapper, so I recommend to use them together. > > Here is my virtualenv and virtualenvwrapper configuration in .zshrc. You > can take a look: > > # Python virtualenvwrapper > export WORKON_HOME=$HOME/.virtualenvs > #export VIRTUALENVWRAPPER_PYTHON=/usr/bin/python2 > > if [ -f /usr/bin/virtualenvwrapper.sh ]; then > source /usr/bin/virtualenvwrapper.sh > fi > > # Python pip -> virtualenv only > export PIP_REQUIRE_VIRTUALENV=true > export PIP_RESPECT_VIRTUALENV=true > Correct me if I'm wrong, but virtualenv can support only the python versions that virtualenv is build on. For example in arch repos there are the latest 2 and 3 python versions. In ruby, rvm/rbenv you can install **any** ruby version and use that per project or globally, etc. Now, in python there is pyenv[0] which is as the author states, a fork of rbenv ported to python. [0] https://github.com/yyuu/pyenv -- GPG : 0x3A7DDABC985EDC6E Blog: http://axilleas.me
