Python 2.7 升 3.4

安装，有PPA可用（支持所有Ubuntu版本及衍生系统）

sudo add-apt-repository ppa:fkrull/deadsnakes
sudo apt-get update
sudo apt-get install python3.4

可见在/usr/bin/下有如下相关文件

python2 python2.7-config python3.4 python-config
python2.7 python2-config python3.4m  python

更新链接

mv /usr/bin/python /usr/bin/python_old
ln -s /usr/bin/python3.4   /usr/bin/python

 安装pip

sudo apt-get install python3-pip
sudo python3 -m easy_install pip
sudo pip3 install <packagename>

据说

Well, on ubuntu 13.10/14.04, things are a little different.

Install

$ sudo apt-get install python3-pip

Install packages

$ sudo pip3 install packagename

Python 2.7 升 3.4

原文：http://www.cnblogs.com/manhua/p/4235049.html