node-sass安装失败解决方法

node-sass安装失败，提示如下：

gyp verb check python checking for Python executable "python" in the PATH
gyp verb `which` succeeded python D:\Program Files\Python38\python.EXE
gyp ERR! configure error
gyp ERR! stack Error: Command failed: D:\Program Files\Python38\python.EXE -c import sys; print "%s.%s.%s" % sys.version_info[:3];
gyp ERR! stack   File "<string>", line 1
gyp ERR! stack     import sys; print "%s.%s.%s" % sys.version_info[:3];
gyp ERR! stack                       ^
gyp ERR! stack SyntaxError: invalid syntax
gyp ERR! stack
gyp ERR! stack     at ChildProcess.exithandler (child_process.js:303:12)
gyp ERR! stack     at ChildProcess.emit (events.js:310:20)
gyp ERR! stack     at maybeClose (internal/child_process.js:1021:16)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:286:5)
gyp ERR! System Windows_NT 10.0.18362
gyp ERR! command "D:\\Program Files\\nodejs\\node.exe" "E:\\JDProject\\renren-fast-vue\\node_modules\\node-gyp\\bin\\node-gyp.js" "rebuild" "--verbose" "--libsass_ext=" "--libsass_cflags=" "--libsass_ldflags=" "--libsass_library="
gyp ERR! cwd E:\JDProject\renren-fast-vue\node_modules\node-sass
gyp ERR! node -v v12.16.3
gyp ERR! node-gyp -v v3.8.0
gyp ERR! not ok
Build failed with error code: 1
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.9 (node_modules\fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.9: wanted {"os":"darwin","arch":"any"} (current: {"os":"win32","arch":"x64"})

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! node-sass@4.9.0 postinstall: `node scripts/build.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the node-sass@4.9.0 postinstall script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\HP\AppData\Roaming\npm-cache\_logs\2020-05-23T06_27_44_952Z-debug.log

原因：

print "%s.%s.%s" % sys.version_info[:3];

为python2.x版本的语法，如果本地安装的是python3.x，就会报此错误

解决方法：

 1. 删除项目中的package-lock.json文件，清除缓存，更新版本号

　　#后续步骤运行npm install 命令时会重新生成package-lock.json文件

rm ./package-lock.json  （如果windows系统，手动删除即可）
# linux 或windows cmd命令窗口下：
npm cache clear --force
npm install -g npm

 2. 修改package-lock.json中依赖包的版本号

    "node-sass": "4.14.1",
    "npm": "^6.14.5",
　　#sass-loader版本为可选项，如果项目很旧，sass-loader版本最好不要改动，否则容易引起项目启动异常
    "sass-loader": "8.0.2",
　　
　　

npm 版本号： npm -v  命令获取

node-sass 版本号：https://www.npmjs.com/package/node-sa      #用比较新的版本

sass-loader 版本号：https://www.npmjs.com/package/sass-loader  #用比较新的版本

 3 重新运行 npm install 命令，即可成功