使用npm install 命令下载依赖报错：

Building: C:\Program Files\nodejs\node.exe E:\blog_web\vue-admin-template-master\node_modules\node-gyp\bin\node-gyp.js rebuild --verbose --libsass_ext= --libsass_cflags= --libsass_ldflags= --libsass_library=
gyp info it worked if it ends with ok
gyp verb cli [
gyp verb cli   'C:\\Program Files\\nodejs\\node.exe',
gyp verb cli   'E:\\blog_web\\vue-admin-template-master\\node_modules\\node-gyp\\bin\\node-gyp.js',
gyp verb cli   'rebuild',
gyp verb cli   '--verbose',
gyp verb cli   '--libsass_ext=',
gyp verb cli   '--libsass_cflags=',
gyp verb cli   '--libsass_ldflags=',
gyp verb cli   '--libsass_library='
gyp verb cli ]
gyp info using node-gyp@3.8.0
gyp info using node@12.18.2 | win32 | x64
gyp verb command rebuild []
gyp verb command clean []
gyp verb clean removing "build" directory
gyp verb command configure []
gyp verb check python checking for Python executable "python2" in the PATH
gyp verb `which` failed Error: not found: python2
gyp verb `which` failed     at getNotFoundError (E:\blog_web\vue-admin-template-master\node_modules\which\which.js:13:12)
gyp verb `which` failed     at F (E:\blog_web\vue-admin-template-master\node_modules\which\which.js:68:19)
gyp verb `which` failed     at E (E:\blog_web\vue-admin-template-master\node_modules\which\which.js:80:29)
gyp verb `which` failed     at E:\blog_web\vue-admin-template-master\node_modules\which\which.js:89:16
gyp verb `which` failed     at E:\blog_web\vue-admin-template-master\node_modules\isexe\index.js:42:5
gyp verb `which` failed     at E:\blog_web\vue-admin-template-master\node_modules\isexe\windows.js:36:5
gyp verb `which` failed     at FSReqCallback.oncomplete (fs.js:167:21)
gyp verb `which` failed  python2 Error: not found: python2
gyp verb `which` failed     at getNotFoundError (E:\blog_web\vue-admin-template-master\node_modules\which\which.js:13:12)
gyp verb `which` failed     at F (E:\blog_web\vue-admin-template-master\node_modules\which\which.js:68:19)
gyp verb `which` failed     at E (E:\blog_web\vue-admin-template-master\node_modules\which\which.js:80:29)
gyp verb `which` failed     at E:\blog_web\vue-admin-template-master\node_modules\which\which.js:89:16
gyp verb `which` failed     at E:\blog_web\vue-admin-template-master\node_modules\isexe\index.js:42:5
gyp verb `which` failed     at E:\blog_web\vue-admin-template-master\node_modules\isexe\windows.js:36:5
gyp verb `which` failed     at FSReqCallback.oncomplete (fs.js:167:21) {
gyp verb `which` failed   code: 'ENOENT'
gyp verb `which` failed }
gyp verb check python checking for Python executable "python" in the PATH
gyp verb `which` failed Error: not found: python
gyp verb `which` failed     at getNotFoundError (E:\blog_web\vue-admin-template-master\node_modules\which\which.js:13:12)
gyp verb `which` failed     at F (E:\blog_web\vue-admin-template-master\node_modules\which\which.js:68:19)
gyp verb `which` failed     at E (E:\blog_web\vue-admin-template-master\node_modules\which\which.js:80:29)
gyp verb `which` failed     at E:\blog_web\vue-admin-template-master\node_modules\which\which.js:89:16
gyp verb `which` failed     at E:\blog_web\vue-admin-template-master\node_modules\isexe\index.js:42:5
gyp verb `which` failed     at E:\blog_web\vue-admin-template-master\node_modules\isexe\windows.js:36:5
gyp verb `which` failed     at FSReqCallback.oncomplete (fs.js:167:21)
gyp verb `which` failed  python Error: not found: python
gyp verb `which` failed     at getNotFoundError (E:\blog_web\vue-admin-template-master\node_modules\which\which.js:13:12)
gyp verb `which` failed     at F (E:\blog_web\vue-admin-template-master\node_modules\which\which.js:68:19)
gyp verb `which` failed     at E (E:\blog_web\vue-admin-template-master\node_modules\which\which.js:80:29)
gyp verb `which` failed     at E:\blog_web\vue-admin-template-master\node_modules\which\which.js:89:16
gyp verb `which` failed     at E:\blog_web\vue-admin-template-master\node_modules\isexe\index.js:42:5
gyp verb `which` failed     at E:\blog_web\vue-admin-template-master\node_modules\isexe\windows.js:36:5
gyp verb `which` failed     at FSReqCallback.oncomplete (fs.js:167:21) {
gyp verb `which` failed   code: 'ENOENT'
gyp verb `which` failed }
gyp verb could not find "python". checking python launcher
gyp verb could not find "python". guessing location 
gyp verb ensuring that file exists: C:\Python27\python.exe
gyp ERR! configure error 
gyp ERR! stack Error: Can't find Python executable "python", you can set the PYTHON env variable.
gyp ERR! stack     at PythonFinder.failNoPython (E:\blog_web\vue-admin-template-master\node_modules\node-gyp\lib\configure.js:484:19)
gyp ERR! stack     at PythonFinder.<anonymous> (E:\blog_web\vue-admin-template-master\node_modules\node-gyp\lib\configure.js:509:16)
gyp ERR! stack     at callback (E:\blog_web\vue-admin-template-master\node_modules\graceful-fs\polyfills.js:295:20)
gyp ERR! stack     at FSReqCallback.oncomplete (fs.js:167:21)
gyp ERR! System Windows_NT 10.0.18362
gyp ERR! command "C:\\Program Files\\nodejs\\node.exe" "E:\\blog_web\\vue-admin-template-master\\node_modules\\node-gyp\\bin\\node-gyp.js" "rebuild" "--verbose" "--libsass_ext=" "--libsass_cflags=" "--libsass_ldflags=" "--libsass_library="
gyp ERR! cwd E:\blog_web\vue-admin-template-master\node_modules\node-sass
gyp ERR! node -v v12.18.2
gyp ERR! node-gyp -v v3.8.0
gyp ERR! not ok
Build failed with error code: 1
npm WARN notsup Unsupported engine for watchpack-chokidar2@2.0.0: wanted: {"node":"<8.10.0"} (current: {"node":"12.18.2","npm":"6.14.5"})
npm WARN notsup Not compatible with your version of node/npm: watchpack-chokidar2@2.0.0
npm WARN script-ext-html-webpack-plugin@2.0.1 requires a peer of html-webpack-plugin@^3.0.0 but none is installed. You must install peer dependencies yourself.
npm WARN vue-admin-template@3.8.0 No repository field.
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules\webpack-dev-server\node_modules\fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {"os":"darwin","arch":"any"} (current: {"os":"win32","arch":"x64"})
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules\watchpack-chokidar2\node_modules\fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {"os":"darwin","arch":"any"} (current: {"os":"win32","arch":"x64"})
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@2.1.3 (node_modules\fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@2.1.3: wanted {"os":"darwin","arch":"any"} (current: {"os":"win32","arch":"x64"})

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! node-sass@4.14.1 postinstall: `node scripts/build.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the node-sass@4.14.1 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\MACHENIKE\AppData\Roaming\npm-cache\_logs\2020-07-07T15_30_39_533Z-debug.log

解决办法：

步骤：1、npm install -g mirror-config-china --registry=http://registry.npm.taobao.org

           2、npm install node-sass