Running Python on Windows for Node.js dependencies

Question

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

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.

Solution 2

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 3

For me after installing windows-build-tools with the below comment

npm --add-python-to-path='true' --debug install --global windows-build-tools

running the code below

npm config set python "%USERPROFILE%\.windows-build-tools\python27\python.exe"

has worked.

Solution 4

Here is a guide that resolved a lot of these issues for me.

http://www.steveworkman.com/node-js/2012/installing-jsdom-on-windows/

I remember in particular the python version as important. Make sure you install 2.7.3 instead of 3's.

Solution 5

One and/or multiple of those should help:

1. Add C:\Python27\ to your PATH variable (considering you have Python installed in this directory)
   How to set PATH env variable: http://www.computerhope.com/issues/ch000549.htm
   Restart your console and/or Windows after setting variable.

2. In the same section as above ("Environment Variables"), add new variable with name PYTHON and value C:\Python27\python.exe
   Restart your console and/or Windows after setting variable.

3. Open Windows command line (cmd) in Admin mode.
   Change directory to your Python installation path: cd C:\Python27
   Make symlink needed for some installations: mklink python2.7.exe python.exe

Please note that you should have Python 2.x, NOT 3.x, to run node-gyp based installations!

The text below says about Unix, but Windows version also requires Python 2.x:

You can install with npm:

$ npm install -g node-gyp
You will also need to install:

On Unix:
python (v2.7 recommended, v3.x.x is not supported)
make
A proper C/C++ compiler toolchain, like GCC

This article may also help: https://github.com/nodejs/node-gyp#installation

View more solutions

Comments

[abarnert]

Can you paste text as text, instead of an image? Besides being hard to read (especially since it's apparently scaled down the already low-res bitmap fonts), it's not copyable.

[abarnert]

More importantly: How did you set the environment variable before rebooting? If you just did PYTHON=C:\Python27\Python.exe in your cmd window and rebooted, the setting was lost.

[abarnert]

Also, which Python version did you install? At least older versions of waf and gyp required 2.x but didn't say anything about it, and would give all kinds of mysterious errors if you installed 3.x instead.

[Matt Cashatt]

Thanks for your comments. I have posted the error in text format. I am using v2.7

[abarnert]

OK, but please answer the "more importantly" question, because that's, as the text implies, important. You may also want to test this yourself: In the cmd.exe window, before trying the npm command, does either python or %PYTHON% start a Python interpreter? If not, you haven't set it up right.

[Matt Cashatt]

set PYTHONPATH=%PYTHONPATH%;C:\My_python_lib

[Matt Cashatt]

Of course I used my actual file path ( not My_python_lib).

[abarnert]

You still only answered half of the question, but… that's more than enough to give you the answer.

[demoncodemonkey]

And if it can't find cl.exe - like it needs for contextify - you'll need to install Visual Studio with C++ too as mentioned here stackoverflow.com/questions/31953769/…

[Matt Cashatt]

OK, so I get this:Microsoft Windows [Version 6.1.7601] Copyright (c) 2009 Microsoft Corporation. All rights reserved. C:\Users\Matt Cashatt>set PYTHON=%PYTHON%;D:\Python C:\Users\Matt Cashatt>%PYTHON% '%PYTHON%' is not recognized as an internal or external command, operable program or batch file. C:\Users\Matt Cashatt>

[Matt Cashatt]

Also, the D drive is where I have Python in case you are wondering. Thanks again for your help.

[Matt Cashatt]

Worked like a charm, thanks! For others: I had to run the set command in the NPM command window for some reason and then run the mpm install jquery command right after that. If I did them separately it didn't work for some reason.

[abarnert]

@MatthewPatrickCashatt: As I explained, the set command only affects the current cmd window, so you have to do it before running npm in the same window. If you want to set environment variables more permanently, that's in the System Control Panel, or equivalent for your version of Windows.

[reach4thelasers]

@abarnert is the actual answer to this question then set PYTHON=D:\Python\bin\Python.exe - would be helpful if you gave the correct way as well as explaining the wrong way

[d.raev]

I had some permissions error, but managed to manually install python from: C:\Users[me]\.windows-build-tools\python.msi . In the installation is an option to add it to the path. (Restarting the cmd/PS ) and it worked

[user1428716]

I get the error dh key too small : openssk\ssl\s3_clnt,c:3641

[Bae]

Installing windows-build-tools required PowerShell run as Admin on Windows 10. This means the setx command becomes setx PYTHON $env:USERPROFILE\.windows-build-tools\python27\python.exe

[FrozenKiwi]

keep in mind: requires Python2.7, 3.X is not supported.

[JeffryHouser]

I did have to run these commands in an elevated command prompt, but it seems to have worked. Manually installing Python 3.x and setting the PYTHON environment variable to point to that did not work. I assume my error related to the difference in python versioning? Thanks regardless!

[StackOverflowUser]

I also needed both of the above steps. I'll also add that, for me, (Windows 10 Pro 1803, node v10.15.3, npm v6.9.0) when I ran the first step, the 'npm install windows-build-tools' step, that install never seemed to complete, it seemed to be looping endlessly (feeding back the same output lines to the console). After watching this seeming endless loop for a number of minutes, I elected to use Ctrl+C to "end the batch job". Everything worked as intended, interrupting the loop didn't appear to be a problem.

[Chamin Thilakarathne]

npm install -g node-gyp was enough

[vitaly-t]

For pg-promise you do not need this. You probably were caught up by this. Just use the latest version, and you will be fine, no need for any of that extra stuff ;)

[MwamiTovi]

Same solution worked for me while installing [email protected], when i switched to windows-10, using [email protected] and [email protected]

[MwamiTovi]

Note that Python36/python should be the path to your python executable file .exe

[MwamiTovi]

If new, goto where your python executable was installed. In windows, Press hold Shift, and Right-Click and enter this: npm config set python

[Juangui Jordán]

The link is unfortunately broken.

[lcnittl]

@JuanguiJordán In the meantime, the required python version is python3

[lcnittl]

Not anymore, luckily.

[Tom Pietrosanti]

The whole point of dependency management is so we don't have to do stuff like this... smh

[KLMN]

npm --vs2015 install --global windows-build-tools resolve my problem. (github.com/felixrieseberg/windows-build-tools/issues/208)

[Brandon Hollenbeck]

I was getting a similar error to OP and I had to set the Python path as well. I set it like this " npm config set python C:\Users\ben\.windows-build-tools\python27\python.exe "

[kaushalpranav]

windows-build-tools is corrupting my anaconda installation by installing a separate python 2.7. For my problem, updating npm version from 6 -> 8, resolved the issue without asking for any python at all. So, I would suggest updating npm before installing windows-build-tools

[sylargaf]

2022, Windows 10, this worked! Thanks