Adding package name after `npm ls` will show you tree only with the specified package.

    npm ls express

I specifically wanted to find what package used a dependency that was breaking an initial install. This may help somebody out trying todo the same:

`find ./node_modules/ -name package.json | xargs grep &lt;the_package_name&gt;`

In case someone is using pnpm, this should help to find packages that depend on lodash for example:

`pnpm list --depth 1 | grep --color -E &#39;(^\w|\slodash)&#39;`

 I have a dataframe with this type of data (too many columns):

    col1        int64
    col2        int64
    col3        category
    col4        category
    col5        category


Columns seems like this:

    Name: col3, dtype: category
    Categories (8, object): [B, C, E, G, H, N, S, W]

I want to convert all value in columns to integer like this:
    
    [1, 2, 3, 4, 5, 6, 7, 8]

I solved this for one column by this:

    dataframe[&#39;c&#39;] = pandas.Categorical.from_array(dataframe.col3).codes

Now I have two columns in my dataframe - old `col3` and new `c` and need to drop old columns. 

That&#39;s bad practice. It&#39;s work but in my dataframe many columns and I don&#39;t want do it manually.  

How do this pythonic and just cleverly?

Convert categorical data in pandas dataframe

I have a Huawei P8 with Android 5.0 that I&#39;m using for testing an app. The app needs to be running in the background, as it tracks BLE regions.  

I&#39;ve discovered that Huawei has built in a &quot;feature&quot; called Protected Apps, that can be accessed from the phone settings (Battery Manager &gt; Protected Apps). This allows elected apps to keep running after the screen is turned off.   

Sensibly for Huawei, but unfortunately for me, it looks like it&#39;s opt-in, i.e. apps are out by default, and you have to manually put them in.
This isn&#39;t a showstopper, as I can advise users in an FAQ or printed documentation about the fix, but I recently installed Tinder (for research purposes!), and noticed that it was put in the protected list automatically.  

Does anyone know how I can do this for my app? Is it a setting in the manifest? Is it something Huawei has enabled for Tinder because it&#39;s a popular app?

&quot;Protected Apps&quot; setting on Huawei phones, and how to handle it

I&#39;d like to find out which packages depend on `express` among the installed `sails/kraken/loopback/hapi/koa` etc. Are there `npm` sub-commands or other ways to locally list all reverse dependencies on one specific npm package?

How to find reverse dependencies on npm package?

<p>I'd like to find out which packages depend on <code>express</code> among the installed <code>sails/kraken/loopback/hapi/koa</code> etc. Are there <code>npm</code> sub-commands or other ways to locally list all reverse dependencies on one specific npm package?</p>


I want to just verify something but have&#39;t been able to find anything in the Express docs or online regarding this (although I know it&#39;s a feature).


I could just test this out but I don&#39;t really have a nice template and would like to hear from the community.

If I define a route in express like such:

    app.get(&#39;/&#39;, function (req, res) {
      res.send(&#39;GET request to homepage&#39;);
    });

I can also define a middleware and load it directly, such as

    middleware = function(req, res){
      res.send(&#39;GET request to homepage&#39;);
    });

    app.get(&#39;/&#39;, middleware)

However, I can also chain at least one of these routes to run extra middleware, such as authentication, as such:

    app.get(&#39;/&#39;, middleware, function (req, res) {
      res.send(&#39;GET request to homepage&#39;);
    });

Are these infinitely chainable? Could I stick 10 middleware functions on a given route if I wanted to? I want to see the parameters that app.get can accept but like mentioned I can&#39;t find it in the docs.


Chaining multiple pieces of middleware for specific route in ExpressJS

In the past, I made some websites with notepad for example, so we must create a folder TREE and put into it a .htm file, and some folderS with stuff like Javascript, css ...

Maybe I don&#39;t understand what NPM really brings, because It seems to do the same thing but automated it ... is it just that ?

For example, why not just unpack a frameworks (e.g. Bootstrap or Kube) without use of NPM and so have folders ready to use ?

Help me to understand please because I&#39;m near the crazy state with all this stuff ...

What is NPM and why do I need it?

Just started working with Node.js. In my `app/js` file, I am doing something like this:

**app.js**


    var http = require(&#39;http&#39;);
    
    http.createServer(function (request, response) {
      response.writeHead(200, {&#39;Content-Type&#39;: &#39;text/plain&#39;});
      response.end(&#39;Am I really running a server?!&#39;);
    }).listen(8080, &#39;127.0.0.1&#39;);
    
    console.log(&#39;running server!&#39;);


When I&#39;m in my terminal and run `node app.js`, the console spits out `&#39;running server!&#39;`, but in my browser I get, `Uncaught ReferenceError: require is not defined`.

Can someone explain to me why in the terminal, it works correctly but in the browser, it doesn&#39;t? 

I am using the node&#39;s `http-server` to serve my page. 

require is not defined? Node.js

I have been playing around with React and so far I really like it. I am building an app with NodeJS and would like to use React for some of the interactive components across the application. I do not want to make it single page app. 

I haven&#39;t yet found anything on the web that answer the following questions:

**How do I break up or bundle  my React components across a multi-page app?**

Currently all my components are in one file even though I may never load them in some sections of the app. 

So far I am trying using conditional statements to render components by searching for the ID of the container where React will render. I am not 100% sure of what the best practices are with React. It looks something like this.

    if(document.getElementById(&#39;a-compenent-in-page-1&#39;)) {
        React.render(
            &lt;AnimalBox url=&quot;/api/birds&quot; /&gt;,
            document.getElementById(&#39;a-compenent-in-page-1&#39;)
        );
    }
        
    if(document.getElementById(&#39;a-compenent-in-page-2&#39;)) {
        React.render(
            &lt;AnimalBox url=&quot;/api/cats&quot; /&gt;,
            document.getElementById(&#39;a-compenent-in-page-2&#39;)
        );
    }

    if(document.getElementById(&#39;a-compenent-in-page-3&#39;)) {
        React.render(
            &lt;AnimalSearchBox url=&quot;/api/search/:term&quot; /&gt;,
            document.getElementById(&#39;a-compenent-in-page-3&#39;)
        );
    }


I am still reading the documentation and haven&#39;t found what I need yet for a multi page app. 

Thanks in advance.

Using React in a multi-page app

I&#39;m receiving this error when trying to debug my node application using the `npm start` command.

#### Error:

&lt;!-- language: lang-none --&gt;

    npm ERR! Windows_NT 6.3.9600
    npm ERR! argv &quot;C:\\Program Files\\nodejs\\\\node.exe&quot; &quot;C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js&quot; &quot;start&quot;
    npm ERR! node v0.12.7
    npm ERR! npm  v2.11.3
    
    npm ERR! missing script: start
    npm ERR!
    npm ERR! If you need help, you may report this error at:
    npm ERR!     &lt;https://github.com/npm/npm/issues&gt;npm ERR! Please include the following file with any support request:
    npm ERR!     C:\Users\andrmoll.NORTHAMERICA\Documents\GitHub\SVIChallenge\npm-debug.log
 

#### From the debug file:

&lt;!-- language: lang-none --&gt;

    Error: missing script: start
           at run (C:\Program Files\nodejs\node_modules\npm\lib\run-script.js:142:19)
           at C:\Program Files\nodejs\node_modules\npm\lib\run-script.js:58:5
           at C:\Program Files\nodejs\node_modules\npm\node_modules\read-package-json\read-json.js:345:5
           at checkBinReferences_ (C:\Program Files\nodejs\node_modules\npm\node_modules\read-package-json\read-json.js:309:45)
           at final (C:\Program Files\nodejs\node_modules\npm\node_modules\read-package-json\read-json.js:343:3)
           at then (C:\Program Files\nodejs\node_modules\npm\node_modules\read-package-json\read-json.js:113:5)
           at C:\Program Files\nodejs\node_modules\npm\node_modules\read-package-json\read-json.js:300:12
           at evalmachine.&lt;anonymous&gt;:334:14
           at C:\Program Files\nodejs\node_modules\npm\node_modules\graceful-fs\graceful-fs.js:102:5
           at FSReqWrap.oncomplete (evalmachine.&lt;anonymous&gt;:95:15)


Start script missing error when running npm start

I have a small node.js project that is company-internal and will not be released publicly or shared with third parties.  It certainly will not be contributed to any public package repositories.

But when I run `npm install` I always get the following error:

    npm WARN package.json &lt;&lt;myproject&gt;&gt;@0.1.0 license should be a valid SPDX license expression

The desired license is: &quot;copyright by us and all rights reserved&quot;.  I could not find anything that looked applicable in the [SPDX license list][1].  The suggestion in [this answer][2] does not work either.  If I simply remove the `license` field from `package.json` the error changes to `no license field`.

How do I get `npm install` to show no errors or warnings without putting a license reference in there that we do not want to use?


  [1]: https://spdx.org/licenses/
  [2]: https://stackoverflow.com/a/30986100/729627

I try to make a gulp compile my sass then autoprefixit with `gulp-autoprefixer` but i&#39;m getting an error.

    var gulp = require(&#39;gulp&#39;),
        sass = require(&#39;gulp-sass&#39;),
        autoprefixer = require(&#39;gulp-autoprefixer&#39;);
    
    gulp.task(&#39;test&#39;, function(){
        gulp.src(&#39;_sass/main.sass&#39;)
            .pipe(sass())
            .pipe(autoprefixer()) 
            .pipe(gulp.dest(&#39;./assets/css&#39;)); 
    });

I&#39;m trying to run this `Gulpfile.js` and i&#39;m using :

    &quot;gulp&quot;: &quot;~3.9.0&quot;,
    &quot;gulp-sass&quot;: &quot;~2.0.4&quot;,
    &quot;gulp-autoprefixer&quot;: &quot;~3.0.1&quot;,
and NPM version `1.3.10`


When i run `gulp test` i get this :  
  

    /home/matei/Tests/test-4/node_modules/gulp-autoprefixer/node_modules/postcss/lib/lazy-result.js:152
            this.processing = new Promise(function (resolve, reject) {
                                  ^
    ReferenceError: Promise is not defined
        at LazyResult.async (/home/matei/Tests/test-4/node_modules/gulp-autoprefixer/node_modules/postcss/lib/lazy-result.js:152:31)
        at LazyResult.then (/home/matei/Tests/test-4/node_modules/gulp-autoprefixer/node_modules/postcss/lib/lazy-result.js:75:21)
        at DestroyableTransform._transform (/home/matei/Tests/test-4/node_modules/gulp-autoprefixer/index.js:28:13)
        at DestroyableTransform.Transform._read (/home/matei/Tests/test-4/node_modules/gulp-autoprefixer/node_modules/through2/node_modules/readable-stream/lib/_stream_transform.js:172:10)
        at DestroyableTransform.Transform._write (/home/matei/Tests/test-4/node_modules/gulp-autoprefixer/node_modules/through2/node_modules/readable-stream/lib/_stream_transform.js:160:12)
        at doWrite (/home/matei/Tests/test-4/node_modules/gulp-autoprefixer/node_modules/through2/node_modules/readable-stream/lib/_stream_writable.js:326:12)
        at writeOrBuffer (/home/matei/Tests/test-4/node_modules/gulp-autoprefixer/node_modules/through2/node_modules/readable-stream/lib/_stream_writable.js:312:5)
        at DestroyableTransform.Writable.write (/home/matei/Tests/test-4/node_modules/gulp-autoprefixer/node_modules/through2/node_modules/readable-stream/lib/_stream_writable.js:239:11)
        at write (/home/matei/Tests/test-4/node_modules/gulp-sass/node_modules/through2/node_modules/readable-stream/lib/_stream_readable.js:623:24)
        at flow (/home/matei/Tests/test-4/node_modules/gulp-sass/node_modules/through2/node_modules/readable-stream/lib/_stream_readable.js:632:7)

I don&#39;t really know what i&#39;m doing wrong. Is not working when i use sass or plain css. I think is something with my files.



Gulp-autoprefixer throwing ReferenceError: Promise is not defined

I want to develop desktop app using [electron][1] that uses sqlite3 package installed via npm with the command

    npm install --save sqlite3

but it gives the following error in electron browser console

    Uncaught Error: Cannot find module &#39;E:\allcode\eapp\node_modules\sqlite3\lib\binding\node-v45-win32-x64\node_sqlite3.node&#39;

My development environment is windows 8.1 x64
node version 12.7


my **package.json** file looks like this:

    {
      &quot;name&quot;: &quot;eapp&quot;,
      &quot;version&quot;: &quot;1.0.0&quot;,
      &quot;description&quot;: &quot;&quot;,
      &quot;main&quot;: &quot;index.js&quot;,
      &quot;scripts&quot;: {
        &quot;start&quot;: &quot;electron .&quot;
      },
      &quot;author&quot;: &quot;&quot;,
      &quot;license&quot;: &quot;ISC&quot;,
      &quot;devDependencies&quot;: {
        &quot;electron-prebuilt&quot;: &quot;^0.32.1&quot;
      },
      &quot;dependencies&quot;: {
        &quot;angular&quot;: &quot;^1.3.5&quot;,   
        &quot;sqlite3&quot;: &quot;^3.1.0&quot;
      }
    }

**index.js file**

    var app = require(&#39;app&#39;);
    var BrowserWindow = require(&#39;browser-window&#39;); 
    require(&#39;crash-reporter&#39;).start();
    var mainWindow = null;
    
    
    app.on(&#39;window-all-closed&#39;, function() {  
        if (process.platform != &#39;darwin&#39;) {
            app.quit();
        }
    });
    
    app.on(&#39;ready&#39;, function() {
        // Create the browser window.
        mainWindow = new BrowserWindow({width: 800, height: 600}); 
        mainWindow.loadUrl(&#39;file://&#39; + __dirname + &#39;/index.html&#39;);   
        mainWindow.openDevTools();  
        mainWindow.on(&#39;closed&#39;, function() {       
            mainWindow = null;
        });
    });

**my.js file** 

    var sqlite3 = require(&#39;sqlite3&#39;).verbose();
    var db = new sqlite3.Database(&#39;mydb.db&#39;);
    
    db.serialize(function() {
        db.run(&quot;CREATE TABLE if not exists lorem (info TEXT)&quot;);
    
        var stmt = db.prepare(&quot;INSERT INTO lorem VALUES (?)&quot;);
        for (var i = 0; i &lt; 10; i++) {
            stmt.run(&quot;Ipsum &quot; + i);
        }
        stmt.finalize();
    
        db.each(&quot;SELECT rowid AS id, info FROM lorem&quot;, function(err, row) {
            console.log(row.id + &quot;: &quot; + row.info);
        });
    });
    
    db.close();

**index.html file**

    &lt;!DOCTYPE html&gt;
    &lt;html&gt;
    &lt;head lang=&quot;en&quot;&gt;
        &lt;meta charset=&quot;UTF-8&quot;&gt;
        &lt;title&gt;&lt;/title&gt;
    &lt;/head&gt;
    &lt;body&gt;
    &lt;div &gt;
        &lt;div&gt;
            &lt;h2&gt;Hello&lt;/h2&gt;
        &lt;/div&gt;
    
    &lt;/div&gt;
    &lt;!--&lt;script src=&quot;js/jquery-1.11.3.min.js&quot;&gt;&lt;/script&gt;--&gt;
    &lt;script src=&quot;js/my.js&quot;&gt;&lt;/script&gt;
    &lt;/body&gt;
    &lt;/html&gt;


  [1]: http://electron.atom.io/

How to use sqlite3 module with electron?

Here is my problem. We have a private NPM registry which only works in VPN. I would like to have a fallback registry https://registry.npmjs.org so that when I am out of VPN it works seamlessly.

**P.S.** Currently I am using [npmrc][1] which does a good job in switching between .npmrc files as a workaround


  [1]: https://www.npmjs.com/package/npmrc

Content Type	Original Author	Original Content on Stackoverflow
Question	sof	View Question on Stackoverflow
Solution 1 - node.js	hassansin	View Answer on Stackoverflow
Solution 2 - node.js	Neil Gaetano Lindberg	View Answer on Stackoverflow
Solution 3 - node.js	peterhil	View Answer on Stackoverflow

How to find reverse dependencies on npm package?

node.js Problem Overview

node.js Solutions

Solution 1 - node.js

Solution 2 - node.js

Solution 3 - node.js

"Protected Apps" setting on Huawei phones, and how to handle it

Convert categorical data in pandas dataframe

Attributions