https://www.zhihu.com/question/30941329
首先终端的“python”命令会执行/usr/local/bin下的“python”链接,链接相当于win下的快捷方式,现在链接指向了python2.7.9的解释器。我们改一下这个链接就好了,建议先备份这个“python”链接,比如像我:
接着把3.4.3的解释器做一个链接到原目录下,请适当修改相关路径:
mv /usr/local/bin/python /Users/python_backup
sudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.4/bin/python3.4 /usr/local/bin/python