npm install 安装不成功，提示python2.7

1.运行npm run dev
出现
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! vue-node-mall@1.0.0 dev: node build/dev-server.js
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the vue-node-mall@1.0.0 dev script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.npm WARN Local package.json exists, but node_modules missing, did you mean to install?

2.运行
npm install --global --production windows-build-tools
3.运行
npm install --save-dev node-sass
4.npm install