npm install error about setting up the python path

Question

I get this error while doing an npm start:

PS C:\Users\Concierge\downloads\prod\pdf2\ipfs_image_uploader> npm start

> react-box@0.1.0 start C:\Users\Concierge\downloads\prod\pdf2\ipfs_image_uploader
> node scripts/start.js

internal/modules/cjs/loader.js:582
    throw err;
    ^

Error: Cannot find module 'dotenv'
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:580:15)
    at Function.Module._load (internal/modules/cjs/loader.js:506:25)
    at Module.require (internal/modules/cjs/loader.js:636:17)
    at require (internal/modules/cjs/helpers.js:20:18)
    at Object.<anonymous> (C:\Users\Concierge\downloads\prod\pdf2\ipfs_image_uploader\scripts\
    at Module._compile (internal/modules/cjs/loader.js:688:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:699:10)
    at Module.load (internal/modules/cjs/loader.js:598:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:537:12)
    at Function.Module._load (internal/modules/cjs/loader.js:529:3)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! react-box@0.1.0 start: `node scripts/start.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the react-box@0.1.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output ab
npm WARN Local package.json exists, but node_modules missing, did you mean to install?

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\Concierge\AppData\Roaming\npm-cache\_logs\2018-11-17T04_27_59_461Z-debug
PS C:\Users\Concierge\downloads\prod\pdf2\ipfs_image_uploader>

and when I run command npm install, I get this error:

> scrypt@6.0.3 preinstall /Users/user/Documents/pdfuploader/node_modules/scrypt
> node node-scrypt-preinstall.js
> scrypt@6.0.3 install /Users/user/Documents/pdfuploader/node_modules/scrypt
> node-gyp rebuild

gyp ERR! configure error 
gyp ERR! stack Error: Can't find Python executable "/path/to/executable/python2.7", you can set the PYTHON env variable.
gyp ERR! stack     at PythonFinder.failNoPython (/usr/local/lib/node_modules/npm/node_modules/node-gyp/lib/configure.js:484:19)
gyp ERR! stack     at PythonFinder.<anonymous> (/usr/local/lib/node_modules/npm/node_modules/node-gyp/lib/configure.js:406:16)
gyp ERR! stack     at F (/usr/local/lib/node_modules/npm/node_modules/which/which.js:68:16)
gyp ERR! stack     at E (/usr/local/lib/node_modules/npm/node_modules/which/which.js:80:29)
gyp ERR! stack     at /usr/local/lib/node_modules/npm/node_modules/which/which.js:89:16
gyp ERR! stack     at /usr/local/lib/node_modules/npm/node_modules/isexe/index.js:42:5
gyp ERR! stack     at /usr/local/lib/node_modules/npm/node_modules/isexe/mode.js:8:5
gyp ERR! stack     at FSReqWrap.oncomplete (fs.js:152:21)
gyp ERR! System Darwin 17.5.0
gyp ERR! command "/usr/local/bin/node" "/usr/local/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild"
gyp ERR! cwd /Users/user/Documents/pdfuploader/node_modules/scrypt
gyp ERR! node -v v8.12.0
gyp ERR! node-gyp -v v3.8.0
gyp ERR! not ok 
npm WARN ajv-keywords@3.2.0 requires a peer of ajv@^6.0.0 but none is installed. You must install peer dependencies yourself.

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! scrypt@6.0.3 install: `node-gyp rebuild`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the scrypt@6.0.3 install 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!     /Users/user/.npm/_logs/2018-11-18T05_45_00_864Z-debug.log`

I tried to set up the pythonpath like here: https://www.tutorialspoint.com/How-to-set-your-python-path-on-Mac but it didn't help

I just sort it out by using this tutorial to insert that path /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages : https://www.howtogeek.com/118594/how-to-edit-your-system-path-for-easy-command-line-access/

but then again i got that error when npm run start: `users-Air:pdfuploader user$ npm run start

client@0.1.0 start /Users/user/Documents/pdfuploader react-scripts start

Could not find a required file. Name: index.html Searched in: /Users/user/Documents/pdfuploader/public npm ERR! code ELIFECYCLE npm ERR! errno 1 npm ERR! client@0.1.0 start: react-scripts start npm ERR! Exit status 1 npm ERR! npm ERR! Failed at the client@0.1.0 start 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! /Users/user/.npm/_logs/2018-11-18T06_44_50_004Z-debug.log`

Files which i am trying to npm run start: https://github.com/damianjnc/pdfuploader

Answer 1

Some of the nodeJS modules are written in c++, and need to be compiled when being installed. This process requires python2 to be installed. Now, most Macs actually have python2 installed by default, but 'python' might not be on your executables path yet.

On a Mac, the python application is typically located at /System/Library/Frameworks/Python.framework/Versions/2.7/bin/python2.7. If there is no 'Python.framework' folder in /System/Library/Frameworks/ you will need to install python. If it is there, then simply symlink the previously mentioned python2.7 executable in /usr/bin. Also ensure that /usr/bin is present on your executable path by typing echo $PATH on your terminal.

To create a symlink run:

cd /usr/bin sudo ln -s /path/to/original/python python