先去python的官網下載最新的python，預設路徑安裝好。

sudo rm -R /System/Library/Frameworks/Python.framework/Versions/2.7

把第一步裡安裝好的Python目錄移到原本系統所持有的目錄位置。

sudo mv /Library/Frameworks/Python.framework/Versions/3.4 /System/Library/Frameworks/Python.framework/Versions

第三步，修改檔案所屬的Group設定Group為wheel，原來系統自帶的就是這樣的

sudo chown -R root:wheel /System/Library/Frameworks/Python.framework/Versions/3.4

sudo rm /System/Library/Frameworks/Python.framework/Versions/Current

sudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.4 /System/Library/Frameworks/Python.framework/Versions/Current

第五步，重新連結可執行檔案

1) 先把系統原來的執行檔案刪掉

sudo rm /usr/bin/pydocsudo rm /usr/bin/pythonsudo rm /usr/bin/pythonwsudo rm /usr/bin/python-config

2) 建立新的連結sudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.4/bin/pydoc3.4 /usr/bin/pydoc

sudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.4/bin/python3.4 /usr/bin/python

sudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.4/bin/pythonw3.4 /usr/bin/pythonw

sudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.4/bin/python3.4m-config /usr/bin/python-config

最後，更新一下.bash_profile檔案在終端輸入vi ~/.bash_profile

按一下i 進入編輯狀態

# 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" 鍵 ，結束編輯並輸入 "：wq" 儲存離開

開啟命令列，輸入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 darwin

Type "help", "copyright", "credits" or "license" for more information.