1、先去python的官网下载最新的python，默认路径安装好。
2、现在要删除mac自带的python，如下：sudo rm -R /System/Library/Frameworks/Python.framework/Versions/2.7把第一步里安装好的Python目录移到原本系统所持有的目录位置。sudo mv /Library/Frameworks/Python.framework/Versions/3.4 /System/Library/Frameworks/Python.framework/Versions
3、第三步，修改文件所属的Group设置Group为wheel，原来系统自带的就是这样的sudo chown -R root:wheel /System/Library/Frameworks/Python.framework/Versions/3.4
4、第四步，更新一下Current的Link在Versions的目录里有一个Current的l坡纠课柩ink，是指向当前的Pyt茑霁酌绡hon版本，原始是指向系统自带的Python2.7，我们把它删除后，link就失效了，所以需要重新链一下sudo rm /System/Library/Frameworks/Python.framework/Versions/Currentsudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.4 /System/Library/Frameworks/Python.framework/Versions/Current
5、第五步，重新链接可执行文件1) 先把系统原来的执行文件删掉sudo rm /usr/bin/pydocsudo rm /usr/bin/pythonsudo rm /usr/bin/pytho荏鱿胫协nwsudo rm /usr/bin/python-config2) 建立新的链接sudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.4/bin/pydoc3.4 /usr/bin/pydocsudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.4/bin/python3.4 /usr/bin/pythonsudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.4/bin/pythonw3.4 /usr/bin/pythonwsudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.4/bin/python3.4m-config /usr/bin/python-config
6、最后，更新一下.bash_profile文件在终端输入vi ~/.bash_profile按一下i 进入编辑状态# Setting PATH for Python 3.4# The orginal version is saved in .bash_profile.pysavePATH="/System/Library/Frameworks/Python.framework/Versions/3.4/bin:${PATH}"export PATH再按一下 "esc" 键 ，结束编辑并输入 "：wq" 存储离开
7、打开命令行，输入python，如下：Python 3.4.1 (v3.4.1:c0e311e010fc, May 18 2014, 00:54:21)[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwinType "help", "copyright", "credits" or "license" for more information.
