tools->build system->new build system

内容替换成:

{
“cmd”: [“/Library/Frameworks/Python.framework/Versions/3.5/bin/python3“, “-u”, “$file”],
“file_regex”: “^[ ]File \”(…?)\”, line ([0-9]*)”,
“selector”: “source.python”,
“encoding”: “utf-8”
}

标红的是python目录,可以用如下命令定位:

which python3

保存,选用默认位置,命名为python3.sublime-build即可

再次进入tools->build system,就可以看到python3了。