Running Python on Windows for Node.js dependencies

I am getting into a Node.js codebase which requires that I download a few dependencies via NPM, namely jQuery.

In attempting to run npm install jquery, I keep getting this error:

Your environment has been set up for using Node.js 0.8.21 (x64) and NPM

C:\Users\Matt Cashatt>npm install jquery
npm http GET https://registry.npmjs.org/jquery
npm http 304 https://registry.npmjs.org/jquery
npm http GET https://registry.npmjs.org/jsdom
npm http GET https://registry.npmjs.org/xmlhttprequest
npm http GET https://registry.npmjs.org/htmlparser/1.7.6
npm http GET https://registry.npmjs.org/location/0.0.1
npm http GET https://registry.npmjs.org/navigator
npm http GET https://registry.npmjs.org/contextify
npm http 304 https://registry.npmjs.org/htmlparser/1.7.6
npm http 304 https://registry.npmjs.org/xmlhttprequest
npm http 304 https://registry.npmjs.org/location/0.0.1
npm http 304 https://registry.npmjs.org/navigator
npm http 304 https://registry.npmjs.org/jsdom
npm http 304 https://registry.npmjs.org/contextify
npm http GET https://registry.npmjs.org/bindings
npm http GET https://registry.npmjs.org/cssom
npm http GET https://registry.npmjs.org/cssstyle
npm http GET https://registry.npmjs.org/request
npm http 304 https://registry.npmjs.org/bindings

> [email protected] install C:\Users\Matt Cashatt\node_modules\jquery\node_module
s\contextify
> node-gyp rebuild


C:\Users\Matt Cashatt\node_modules\jquery\node_modules\contextify>node "C:\Progr
am Files\nodejs\node_modules\npm\bin\node-gyp-bin\\..\..\node_modules\node-gyp\b
in\node-gyp.js" rebuild
npm http 304 https://registry.npmjs.org/cssstyle
npm http 304 https://registry.npmjs.org/cssom
npm http 304 https://registry.npmjs.org/request
gyp ERR! configure error
gyp ERR! stack Error: Can't find Python executable "python", you can set the PYT
HON env variable.
gyp ERR! stack     at failNoPython (C:\Program Files\nodejs\node_modules\npm\nod
e_modules\node-gyp\lib\configure.js:113:14)
gyp ERR! stack     at C:\Program Files\nodejs\node_modules\npm\node_modules\node
-gyp\lib\configure.js:82:11
gyp ERR! stack     at Object.oncomplete (fs.js:297:15)
gyp ERR! System Windows_NT 6.1.7601
gyp ERR! command "node" "C:\\Program Files\\nodejs\\node_modules\\npm\\node_modu
les\\node-gyp\\bin\\node-gyp.js" "rebuild"
gyp ERR! cwd C:\Users\Matt Cashatt\node_modules\jquery\node_modules\contextify
gyp ERR! node -v v0.8.21
gyp ERR! node-gyp -v v0.8.4
gyp ERR! not ok
npm ERR! error rolling back Error: ENOTEMPTY, rmdir 'C:\Users\Matt Cashatt\node_
modules\jquery\node_modules\jsdom\node_modules\request\tests'
npm ERR! error rolling back  [email protected] { [Error: ENOTEMPTY, rmdir 'C:\Users\M
att Cashatt\node_modules\jquery\node_modules\jsdom\node_modules\request\tests']
npm ERR! error rolling back   errno: 53,
npm ERR! error rolling back   code: 'ENOTEMPTY',
npm ERR! error rolling back   path: 'C:\\Users\\Matt Cashatt\\node_modules\\jque
ry\\node_modules\\jsdom\\node_modules\\request\\tests' }
npm ERR! [email protected] install: `node-gyp rebuild`
npm ERR! `cmd "/c" "node-gyp rebuild"` failed with 1
npm ERR!
npm ERR! Failed at the [email protected] install script.
npm ERR! This is most likely a problem with the contextify package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     node-gyp rebuild
npm ERR! You can get their info via:
npm ERR!     npm owner ls contextify
npm ERR! There is likely additional logging output above.

npm ERR! System Windows_NT 6.1.7601
npm ERR! command "C:\\Program Files\\nodejs\\\\node.exe" "C:\\Program Files\\nod
ejs\\node_modules\\npm\\bin\\npm-cli.js" "install" "jquery"
npm ERR! cwd C:\Users\Matt Cashatt
npm ERR! node -v v0.8.21
npm ERR! npm -v 1.2.11
npm ERR! code ELIFECYCLE
npm ERR! Error: ENOENT, lstat 'C:\Users\Matt Cashatt\node_modules\jquery\node_mo
dules\jsdom\node_modules\request\tests\test-pipes.js'
npm ERR! If you need help, you may report this log at:
npm ERR!     <http://github.com/isaacs/npm/issues>
npm ERR! or email it to:
npm ERR!     <[email protected]>

npm ERR! System Windows_NT 6.1.7601
npm ERR! command "C:\\Program Files\\nodejs\\\\node.exe" "C:\\Program Files\\nod
ejs\\node_modules\\npm\\bin\\npm-cli.js" "install" "jquery"
npm ERR! cwd C:\Users\Matt Cashatt
npm ERR! node -v v0.8.21
npm ERR! npm -v 1.2.11
npm ERR! path C:\Users\Matt Cashatt\node_modules\jquery\node_modules\jsdom\node_
modules\request\tests\test-pipes.js
npm ERR! fstream_path C:\Users\Matt Cashatt\node_modules\jquery\node_modules\jsd
om\node_modules\request\tests\test-pipes.js
npm ERR! fstream_type File
npm ERR! fstream_class FileWriter
npm ERR! code ENOENT
npm ERR! errno 34
npm ERR! fstream_stack C:\Program Files\nodejs\node_modules\npm\node_modules\fst
ream\lib\writer.js:284:26
npm ERR! fstream_stack Object.oncomplete (fs.js:297:15)
npm ERR!
npm ERR! Additional logging details can be found in:
npm ERR!     C:\Users\Matt Cashatt\npm-debug.log
npm ERR! not ok code 0

C:\Users\Matt Cashatt>

It looks like the failure is due to a missing Python installation. Well, I have installed Python, set the variable, and rebooted and still the error.

Any clue as to what I am missing?

Solution 1:

If you haven't got python installed along with all the node-gyp dependencies, simply open Powershell or Git Bash with administrator privileges and execute:

npm install --global --production windows-build-tools

and then to install the package:

npm install --global node-gyp

once installed, you will have all the node-gyp dependencies downloaded, but you still need the environment variable. Validate Python is indeed found in the correct folder:

C:\Users\ben\.windows-build-tools\python27\python.exe 

*Note - it uses python 2.7 not 3.x as it is not supported*

If it doesn't moan, go ahead and create your (user) environment variable:

setx PYTHON "%USERPROFILE%\.windows-build-tools\python27\python.exe"

restart cmd, and verify the variable exists via set PYTHON which should return the variable ($env:PYTHON if using Powershell)

Lastly re-apply npm install <module>

Solution 2:

Your problem is that you didn't set the environment variable.

The error clearly says this:

gyp ERR! stack Error: Can't find Python executable "python", you can set the PYTHON env variable.

And in your comment, you say you did this:

set PYTHONPATH=%PYTHONPATH%;C:\My_python_lib

That's nice, but that doesn't set the PYTHON variable, it sets the PYTHONPATH variable.

Meanwhile, just using the set command only affects the current cmd session. If you reboot after that, as you say you did, you end up with a whole new cmd session that doesn't have that variable set in it.

There are a few ways to set environment variables permanently—the easiest is in the System Control Panel in XP, which is of course different in Vista, different again in 7, and different again in 8, but you can google for it.

Alternatively, just do the set right before the npm command, without rebooting in between.

You can test whether you've done things right by doing the exact same thing the config script is trying to do: Before running npm, try running %PYTHON%. If you've done it right, you'll get a Python interpreter (which you can immediately quit). If you get an error, you haven't done it right.

There are two problems with this:

set PYTHON=%PYTHON%;D:\Python

First, you're setting PYTHON to ;D:\Python. That extra semicolon is fine for a semicolon-separated list of paths, like PATH or PYTHONPATH, but not for a single value like PYTHON. And likewise, adding a new value to the existing value is what you want when you want to add another path to a list of paths, but not for a single value. So, you just want set PYTHON=D:\Python.

Second, D:\Python is not the path to your Python interpreter. It's something like D:\Python\Python.exe, or D:\Python\bin\Python.exe. Find the right path, make sure it works on its own (e.g., type D:\Python\bin\Python.exe and make sure you get a Python interpreter), then set the variable and use it.

So:

set PYTHON=D:\Python\bin\Python.exe

Or, if you want to make it permanent, do the equivalent in the Control Panel.