Mac替换python环境

将mac本地python环境从3.6切为3.7

1. 先将软链接重命名
   mv /usr/local/bin/python /usr/local/bin/python3.6
2. 创建新的python软链接
   ln -s /opt/anaconda3/bin/python3.7 /usr/local/bin/python
3. pip也别忘记了
   mv /usr/local/bin/pip /usr/local/bin/pip3.6
ln -s /opt/anaconda3/bin/pip /usr/local/bin/pip