Programs & Examples On #Development process

A development process is a set of practices, roles and artifacts performed/created during development. **Important note:** General development methodology questions should be posted on Software Engineering SE or Project Management SE instead.

What should be the values of GOPATH and GOROOT?

Starting with go 1.8 (Q2 2017), GOPATH will be set for you by default to $HOME/go

See issue 17262 and Rob Pike's comment:

$HOME/go it will be.
There is no single best answer but this is short and sweet, and it can only be a problem to choose that name if $HOME/go already exists, which will only happy for experts who already have go installed and will understand GOPATH.

Format a Go string without printing?

In your case, you need to use Sprintf() for format string.

func Sprintf(format string, a ...interface{}) string

Sprintf formats according to a format specifier and returns the resulting string.

s := fmt.Sprintf("Good Morning, This is %s and I'm living here from last %d years ", "John", 20)

Your output will be :

Good Morning, This is John and I'm living here from last 20 years.

How to search in an array with preg_match?

$items = array();
foreach ($haystacks as $haystack) {
    if (preg_match($pattern, $haystack, $matches)
        $items[] = $matches[1];
}

Best HTML5 markup for sidebar

The book HTML5 Guidelines for Web Developers: Structure and Semantics for Documents suggested this way (option 1):

<aside id="sidebar">
    <section id="widget_1"></section>
    <section id="widget_2"></section>
    <section id="widget_3"></section>
</aside>

It also points out that you can use sections in the footer. So section can be used outside of the actual page content.

How do I give text or an image a transparent background using CSS?

There's an easier solution to put an overlay over an image on the same div. It's not the right use of this tool. But works like a charm to make that overlay using CSS.

Use an inset shadow like this:

box-shadow: inset 0 0 0 1000px rgba(255, 255, 255, 0.9);

That's all :)

ECONNREFUSED error when connecting to mongodb from node.js

I also got stucked with same problem so I fixed it like this :

If you are running mongo and nodejs in docker container or in docker compose

so replace localhost with mongo (which is container name in docker in my case) something like this below in your nodejs mongo connection file.

var mongoURI = "mongodb://mongo:27017/<nodejs_container_name>";

Displaying Windows command prompt output and redirecting it to a file

I install perl on most of my machines so an answer using perl: tee.pl

my $file = shift || "tee.dat";
open $output, ">", $file or die "unable to open $file as output: $!";
while(<STDIN>)
{
    print $_;
    print $output $_;
}
close $output;

dir | perl tee.pl or dir | perl tee.pl dir.bat

crude and untested.

J2ME/Android/BlackBerry - driving directions, route between two locations

J2ME Map Route Provider

maps.google.com has a navigation service which can provide you route information in KML format.

To get kml file we need to form url with start and destination locations:

public static String getUrl(double fromLat, double fromLon,
                            double toLat, double toLon) {// connect to map web service
    StringBuffer urlString = new StringBuffer();
    urlString.append("http://maps.google.com/maps?f=d&hl=en");
    urlString.append("&saddr=");// from
    urlString.append(Double.toString(fromLat));
    urlString.append(",");
    urlString.append(Double.toString(fromLon));
    urlString.append("&daddr=");// to
    urlString.append(Double.toString(toLat));
    urlString.append(",");
    urlString.append(Double.toString(toLon));
    urlString.append("&ie=UTF8&0&om=0&output=kml");
    return urlString.toString();
}

Next you will need to parse xml (implemented with SAXParser) and fill data structures:

public class Point {
    String mName;
    String mDescription;
    String mIconUrl;
    double mLatitude;
    double mLongitude;
}

public class Road {
    public String mName;
    public String mDescription;
    public int mColor;
    public int mWidth;
    public double[][] mRoute = new double[][] {};
    public Point[] mPoints = new Point[] {};
}

Network connection is implemented in different ways on Android and Blackberry, so you will have to first form url:

 public static String getUrl(double fromLat, double fromLon,
     double toLat, double toLon)

then create connection with this url and get InputStream.
Then pass this InputStream and get parsed data structure:

 public static Road getRoute(InputStream is) 

Full source code RoadProvider.java

BlackBerry

class MapPathScreen extends MainScreen {
    MapControl map;
    Road mRoad = new Road();
    public MapPathScreen() {
        double fromLat = 49.85, fromLon = 24.016667;
        double toLat = 50.45, toLon = 30.523333;
        String url = RoadProvider.getUrl(fromLat, fromLon, toLat, toLon);
        InputStream is = getConnection(url);
        mRoad = RoadProvider.getRoute(is);
        map = new MapControl();
        add(new LabelField(mRoad.mName));
        add(new LabelField(mRoad.mDescription));
        add(map);
    }
    protected void onUiEngineAttached(boolean attached) {
        super.onUiEngineAttached(attached);
        if (attached) {
            map.drawPath(mRoad);
        }
    }
    private InputStream getConnection(String url) {
        HttpConnection urlConnection = null;
        InputStream is = null;
        try {
            urlConnection = (HttpConnection) Connector.open(url);
            urlConnection.setRequestMethod("GET");
            is = urlConnection.openInputStream();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return is;
    }
}

See full code on J2MEMapRouteBlackBerryEx on Google Code

Android

Android G1 screenshot

public class MapRouteActivity extends MapActivity {
    LinearLayout linearLayout;
    MapView mapView;
    private Road mRoad;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);
        new Thread() {
            @Override
            public void run() {
                double fromLat = 49.85, fromLon = 24.016667;
                double toLat = 50.45, toLon = 30.523333;
                String url = RoadProvider
                        .getUrl(fromLat, fromLon, toLat, toLon);
                InputStream is = getConnection(url);
                mRoad = RoadProvider.getRoute(is);
                mHandler.sendEmptyMessage(0);
            }
        }.start();
    }

    Handler mHandler = new Handler() {
        public void handleMessage(android.os.Message msg) {
            TextView textView = (TextView) findViewById(R.id.description);
            textView.setText(mRoad.mName + " " + mRoad.mDescription);
            MapOverlay mapOverlay = new MapOverlay(mRoad, mapView);
            List<Overlay> listOfOverlays = mapView.getOverlays();
            listOfOverlays.clear();
            listOfOverlays.add(mapOverlay);
            mapView.invalidate();
        };
    };

    private InputStream getConnection(String url) {
        InputStream is = null;
        try {
            URLConnection conn = new URL(url).openConnection();
            is = conn.getInputStream();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return is;
    }
    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }
}

See full code on J2MEMapRouteAndroidEx on Google Code

How can you encode a string to Base64 in JavaScript?

Here is a LIVE DEMO of atob() and btoa() JS built in functions:

<!DOCTYPE html>
<html>
  <head>
    <style>
      textarea{
        width:30%;
        height:100px;
      }
    </style>
    <script>
      // encode string to base64
      function encode()
      {
        var txt = document.getElementById("txt1").value;
        var result = btoa(txt);
        document.getElementById("txt2").value = result;
      }
      // decode base64 back to original string
      function decode()
      {
        var txt = document.getElementById("txt3").value;
        var result = atob(txt);
        document.getElementById("txt4").value = result;
      }
    </script>
  </head>
  <body>
    <div>
      <textarea id="txt1">Some text to decode
      </textarea>
    </div>
    <div>
      <input type="button" id="btnencode" value="Encode" onClick="encode()"/>
    </div>
    <div>
      <textarea id="txt2">
      </textarea>
    </div>
    <br/>
    <div>
      <textarea id="txt3">U29tZSB0ZXh0IHRvIGRlY29kZQ==
      </textarea>
    </div>
    <div>
      <input type="button" id="btndecode" value="Decode" onClick="decode()"/>
    </div>
    <div>
      <textarea id="txt4">
      </textarea>
    </div>
  </body>
</html>

Does Python have a ternary conditional operator?

More a tip than an answer (don't need to repeat the obvious for the hundreth time), but I sometimes use it as a oneliner shortcut in such constructs:

if conditionX:
    print('yes')
else:
    print('nah')

, becomes:

print('yes') if conditionX else print('nah')

Some (many :) may frown upon it as unpythonic (even, ruby-ish :), but I personally find it more natural - i.e. how you'd express it normally, plus a bit more visually appealing in large blocks of code.

Merge 2 arrays of objects

Merging two arrays:

var arr1 = new Array({name: "lang", value: "English"}, {name: "age", value: "18"});
var arr2 = new Array({name : "childs", value: '5'}, {name: "lang", value: "German"});
var result=arr1.concat(arr2);
// result: [{name: "lang", value: "English"}, {name: "age", value: "18"}, {name : "childs", value: '5'}, {name: "lang", value: "German"}]

Merging two arrays without duplicated values for 'name':

var arr1 = new Array({name: "lang", value: "English"}, {name: "age", value: "18"});
var arr2 = new Array({name : "childs", value: '5'}, {name: "lang", value: "German"});
var i,p,obj={},result=[];
for(i=0;i<arr1.length;i++)obj[arr1[i].name]=arr1[i].value;
for(i=0;i<arr2.length;i++)obj[arr2[i].name]=arr2[i].value;
for(p in obj)if(obj.hasOwnProperty(p))result.push({name:p,value:obj[p]});
// result: [{name: "lang", value: "German"}, {name: "age", value: "18"}, {name : "childs", value: '5'}]

<input type="file"> limit selectable files by extensions

Easy way of doing it would be:

<input type="file" accept=".gif,.jpg,.jpeg,.png,.doc,.docx">

Works with all browsers, except IE9. I haven't tested it in IE10+.

How does one capture a Mac's command key via JavaScript?

EDIT: As of 2019, e.metaKey is supported on all major browsers as per the MDN.

Note that on Windows, although the ? Windows key is considered to be the "meta" key, it is not going to be captured by browsers as such.

This is only for the command key on MacOS/keyboards.


Unlike Shift/Alt/Ctrl, the Cmd (“Apple”) key is not considered a modifier key—instead, you should listen on keydown/keyup and record when a key is pressed and then depressed based on event.keyCode.

Unfortunately, these key codes are browser-dependent:

  • Firefox: 224
  • Opera: 17
  • WebKit browsers (Safari/Chrome): 91 (Left Command) or 93 (Right Command)

You might be interested in reading the article JavaScript Madness: Keyboard Events, from which I learned that knowledge.

How can I count the occurrences of a string within a file?

This will output the number of lines that contain your search string.

grep -c "echo" FILE

This won't, however, count the number of occurrences in the file (ie, if you have echo multiple times on one line).

edit:

After playing around a bit, you could get the number of occurrences using this dirty little bit of code:

sed 's/echo/echo\n/g' FILE | grep -c "echo"

This basically adds a newline following every instance of echo so they're each on their own line, allowing grep to count those lines. You can refine the regex if you only want the word "echo", as opposed to "echoing", for example.

HighCharts Hide Series Name from the Legend

showInLegend is a series-specific option that can hide the series from the legend. If the requirement is to hide the legends completely then it is better to use enabled: false property as shown below:

legend: { enabled: false }

More information about legend is here

java.io.FileNotFoundException: (Access is denied)

  1. check the rsp's reply
  2. check that you have permissions to read the file
  3. check whether the file is not locked by other application. It is relevant mostly if you are on windows. for example I think that you can get the exception if you are trying to read the file while it is opened in notepad

What does O(log n) mean exactly?

If you had a function that takes:

1 millisecond to complete if you have 2 elements.
2 milliseconds to complete if you have 4 elements.
3 milliseconds to complete if you have 8 elements.
4 milliseconds to complete if you have 16 elements.
...
n milliseconds to complete if you have 2^n elements.

Then it takes log2(n) time. The Big O notation, loosely speaking, means that the relationship only needs to be true for large n, and that constant factors and smaller terms can be ignored.

rbenv not changing ruby version

This happened to me right after I reinstalled rbenv. Apparently I had a .ruby-version file in my home directory, specifying a version that no longer existed. Once I deleted the file, everything worked.

How to pass a variable to the SelectCommand of a SqlDataSource?

Try this instead, remove the SelectCommand property and SelectParameters:

<asp:SqlDataSource ID="SqlDataSource1" runat="server" 
    ConnectionString="<%$ ConnectionStrings:itematConnectionString %>">

Then in the code behind do this:

SqlDataSource1.SelectParameters.Add("userId", userId.ToString());

SqlDataSource1.SelectCommand = "SELECT items.name, items.id FROM items INNER JOIN users_items ON items.id = users_items.id WHERE (users_items.user_id = @userId) ORDER BY users_items.date DESC"

While this worked for me, the following code also works:

<asp:SqlDataSource ID="SqlDataSource1" runat="server" 
    ConnectionString="<%$ ConnectionStrings:itematConnectionString %>"
    SelectCommand = "SELECT items.name, items.id FROM items INNER JOIN users_items ON items.id = users_items.id WHERE (users_items.user_id = @userId) ORDER BY users_items.date DESC"></asp:SqlDataSource>


SqlDataSource1.SelectParameters.Add("userid", DbType.Guid, userId.ToString());

Null or empty check for a string variable

Yes, it works. Check the below example. Assuming @value is not int

WITH CTE 
AS
(
    SELECT NULL AS test
    UNION
    SELECT '' AS test
    UNION
    SELECT '123' AS test
)

SELECT 
    CASE WHEN isnull(test,'')='' THEN 'empty' ELSE test END AS IS_EMPTY 
FROM CTE

Result :

IS_EMPTY
--------
empty
empty
123

How to rename JSON key

If you want to rename all occurrences of some key you can use a regex with the g option. For example:

var json = [{"_id":"1","email":"[email protected]","image":"some_image_url","name":"Name 1"},{"_id":"2","email":"[email protected]","image":"some_image_url","name":"Name 2"}];

str = JSON.stringify(json);

now we have the json in string format in str.

Replace all occurrences of "_id" to "id" using regex with the g option:

str = str.replace(/\"_id\":/g, "\"id\":");

and return to json format:

json = JSON.parse(str);

now we have our json with the wanted key name.

SQlite - Android - Foreign key syntax

Since I cannot comment, adding this note in addition to @jethro answer.

I found out that you also need to do the FOREIGN KEY line as the last part of create the table statement, otherwise you will get a syntax error when installing your app. What I mean is, you cannot do something like this:

private static final String TASK_TABLE_CREATE = "create table "
    + TASK_TABLE + " (" + TASK_ID
    + " integer primary key autoincrement, " + TASK_TITLE
    + " text not null, " + TASK_NOTES + " text not null, "
+ TASK_CAT + " integer,"
+ " FOREIGN KEY ("+TASK_CAT+") REFERENCES "+CAT_TABLE+" ("+CAT_ID+"), "
+ TASK_DATE_TIME + " text not null);";

Where I put the TASK_DATE_TIME after the foreign key line.

Resize external website content to fit iFrame width

Tip for 1 website resizing the height. But you can change to 2 websites.

Here is my code to resize an iframe with an external website. You need insert a code into the parent (with iframe code) page and in the external website as well, so, this won't work with you don't have access to edit the external website.

  • local (iframe) page: just insert a code snippet
  • remote (external) page: you need a "body onload" and a "div" that holds all contents. And body needs to be styled to "margin:0"

Local:

<IFRAME STYLE="width:100%;height:1px" SRC="http://www.remote-site.com/" FRAMEBORDER="no" BORDER="0" SCROLLING="no" ID="estframe"></IFRAME>

<SCRIPT>
var eventMethod = window.addEventListener ? "addEventListener" : "attachEvent";
var eventer = window[eventMethod];
var messageEvent = eventMethod == "attachEvent" ? "onmessage" : "message";
eventer(messageEvent,function(e) {
  if (e.data.substring(0,3)=='frm') document.getElementById('estframe').style.height = e.data.substring(3) + 'px';
},false);
</SCRIPT>

You need this "frm" prefix to avoid problems with other embeded codes like Twitter or Facebook plugins. If you have a plain page, you can remove the "if" and the "frm" prefix on both pages (script and onload).

Remote:

You need jQuery to accomplish about "real" page height. I cannot realize how to do with pure JavaScript since you'll have problem when resize the height down (higher to lower height) using body.scrollHeight or related. For some reason, it will return always the biggest height (pre-redimensioned).

<BODY onload="parent.postMessage('frm'+$('#master').height(),'*')" STYLE="margin:0">
<SCRIPT SRC="path-to-jquery/jquery.min.js"></SCRIPT>
<DIV ID="master">
your content
</DIV>

So, parent page (iframe) has a 1px default height. The script inserts a "wait for message/event" from the iframe. When a message (post message) is received and the first 3 chars are "frm" (to avoid the mentioned problem), will get the number from 4th position and set the iframe height (style), including 'px' unit.

The external site (loaded in the iframe) will "send a message" to the parent (opener) with the "frm" and the height of the main div (in this case id "master"). The "*" in postmessage means "any source".

Hope this helps. Sorry for my english.

How to deserialize a JObject to .NET object

According to this post, it's much better now:

// pick out one album
JObject jalbum = albums[0] as JObject;

// Copy to a static Album instance
Album album = jalbum.ToObject<Album>();

Documentation: Convert JSON to a Type

How to dismiss keyboard for UITextView with return key?

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range  replacementText:(NSString *)text
{
    if (range.length==0) {
        if ([text isEqualToString:@"\n"]) {
            [txtView resignFirstResponder];
            if(textView.returnKeyType== UIReturnKeyGo){

                [self PreviewLatter];
                return NO;
            }
            return NO;
        }
    }   return YES;
}

Difference between System.DateTime.Now and System.DateTime.Today

Time. .Now includes the 09:23:12 or whatever; .Today is the date-part only (at 00:00:00 on that day).

So use .Now if you want to include the time, and .Today if you just want the date!

.Today is essentially the same as .Now.Date

how to declare global variable in SQL Server..?

It is not possible to declare global variables in SQL Server. Sql server has a concept of global variables, but they are system defined and can not be extended.

obviously you can do all kinds of tricks with the SQL you are sending - SqlCOmmand has such a variable replacement mechanism for example - BEFORE you send it to SqlServer, but that is about it.

document.createElement("script") synchronously

This isn't pretty, but it works:

<script type="text/javascript">
  document.write('<script type="text/javascript" src="other.js"></script>');
</script>

<script type="text/javascript">
  functionFromOther();
</script>

Or

<script type="text/javascript">
  document.write('<script type="text/javascript" src="other.js"></script>');
  window.onload = function() {
    functionFromOther();
  };
</script>

The script must be included either in a separate <script> tag or before window.onload().

This will not work:

<script type="text/javascript">
  document.write('<script type="text/javascript" src="other.js"></script>');
  functionFromOther(); // Error
</script>

The same can be done with creating a node, as Pointy did, but only in FF. You have no guarantee when the script will be ready in other browsers.

Being an XML Purist I really hate this. But it does work predictably. You could easily wrap those ugly document.write()s so you don't have to look at them. You could even do tests and create a node and append it then fall back on document.write().

How to give a pattern for new line in grep?

You can use this way...

grep -P '^\s$' file
  • -P is used for Perl regular expressions (an extension to POSIX grep).
  • \s match the white space characters; if followed by *, it matches an empty line also.
  • ^ matches the beginning of the line. $ matches the end of the line.

Regex for parsing directory and filename

Most languages have path parsing functions that will give you this already. If you have the ability, I'd recommend using what comes to you for free out-of-the-box.

Assuming / is the path delimiter...

^(.*/)([^/]*)$

The first group will be whatever the directory/path info is, the second will be the filename. For example:

  • /foo/bar/baz.log: "/foo/bar/" is the path, "baz.log" is the file
  • foo/bar.log: "foo/" is the path, "bar.log" is the file
  • /foo/bar: "/foo/" is the path, "bar" is the file
  • /foo/bar/: "/foo/bar/" is the path and there is no file.

How can I set the default timezone in node.js?

You can config global timezone with the library tzdata:

npm install tzdata -y

After set your environment with the variable for example: TZ=America/Bogota

And testing in your project:

new Date()

I hope helpyou

installing requests module in python 2.7 windows

  1. Download the source code(zip or rar package).
  2. Run the setup.py inside.

position fixed is not working

My issue was that a parent element had transform: scale(1); this apparently makes it impossible for any element to be fixed inside it. By removing that everything works normally...

It seems to be like this in all browsers I tested (Chrome, Safari) so don't know if it comes from some strange web standard.

(It's a popup that goes from scale(0) to scale(1))

Converting JSON data to Java object

Or with Jackson:

String json = "...
ObjectMapper m = new ObjectMapper();
Set<Product> products = m.readValue(json, new TypeReference<Set<Product>>() {});

MongoDB: Combine data from multiple collections into one..how?

If there is no bulk insert into mongodb, we loop all objects in the small_collection and insert them one by one into the big_collection:

db.small_collection.find().forEach(function(obj){ 
   db.big_collection.insert(obj)
});

How do I add one month to current date in Java?

You can make use of apache's commons lang DateUtils helper utility class.

Date newDate = DateUtils.addMonths(new Date(), 1);

You can download commons lang jar at http://commons.apache.org/proper/commons-lang/

How do I trim whitespace from a string?

Just one space or all consecutive spaces? If the second, then strings already have a .strip() method:

>>> ' Hello '.strip()
'Hello'
>>> ' Hello'.strip()
'Hello'
>>> 'Bob has a cat'.strip()
'Bob has a cat'
>>> '   Hello   '.strip()  # ALL consecutive spaces at both ends removed
'Hello'

If you only need to remove one space however, you could do it with:

def strip_one_space(s):
    if s.endswith(" "): s = s[:-1]
    if s.startswith(" "): s = s[1:]
    return s

>>> strip_one_space("   Hello ")
'  Hello'

Also, note that str.strip() removes other whitespace characters as well (e.g. tabs and newlines). To remove only spaces, you can specify the character to remove as an argument to strip, i.e.:

>>> "  Hello\n".strip(" ")
'Hello\n'

Android: remove left margin from actionbar's custom layout

Only add app:contentInsetStart="0dp" to the toolbar remove that left space.

So your Toolbar definition look like this

 <android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    app:contentInsetStart="0dp"
    android:layout_height="?attr/actionBarSize"
    android:background="?attr/colorPrimary"
    app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
    app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

and it look like this

enter image description here

getting the X/Y coordinates of a mouse click on an image with jQuery

The below code works always even if any image makes the window scroll.

$(function() {
    $("#demo-box").click(function(e) {

      var offset = $(this).offset();
      var relativeX = (e.pageX - offset.left);
      var relativeY = (e.pageY - offset.top);

      alert("X: " + relativeX + "  Y: " + relativeY);

    });
});

Ref: http://css-tricks.com/snippets/jquery/get-x-y-mouse-coordinates/

VARCHAR to DECIMAL

In MySQL

select convert( if( listPrice REGEXP '^[0-9]+$', listPrice, '0' ), DECIMAL(15, 3) ) from MyProduct WHERE 1

Enable/Disable a dropdownbox in jquery

Here is one way that I hope is easy to understand:

http://jsfiddle.net/tft4t/

$(document).ready(function() {
 $("#chkdwn2").click(function() {
   if ($(this).is(":checked")) {
      $("#dropdown").prop("disabled", true);
   } else {
      $("#dropdown").prop("disabled", false);  
   }
 });
});

How to convert integer to char in C?

To convert int to char use:

int a=8;  
char c=a+'0';
printf("%c",c);       //prints 8  

To Convert char to int use:

char c='5';
int a=c-'0';
printf("%d",a);        //prints 5

Changing the text on a label

I made a small tkinter application which is sets the label after button clicked

#!/usr/bin/env python
from Tkinter import *
from tkFileDialog import askopenfilename
from tkFileDialog import askdirectory


class Application:
    def __init__(self, master):
        frame = Frame(master,width=200,height=200)
        frame.pack()

        self.log_file_btn = Button(frame, text="Select Log File", command=self.selectLogFile,width=25).grid(row=0)
        self.image_folder_btn = Button(frame, text="Select Image Folder", command=self.selectImageFile,width=25).grid(row=1)
        self.quite_button = Button(frame, text="QUIT", fg="red", command=frame.quit,width=25).grid(row=5)

        self.logFilePath =StringVar()
        self.imageFilePath = StringVar()
        self.labelFolder = Label(frame,textvariable=self.logFilePath).grid(row=0,column=1)
        self.labelImageFile = Label(frame,textvariable = self.imageFilePath).grid(row = 1,column=1)

        def selectLogFile(self):
            filename = askopenfilename()
            self.logFilePath.set(filename)

        def selectImageFile(self):
            imageFolder = askdirectory()
            self.imageFilePath.set(imageFolder)

root = Tk()
root.title("Geo Tagging")
root.geometry("600x100")
app = Application(root)
root.mainloop()

Using scanner.nextLine()

It's because when you enter a number then press Enter, input.nextInt() consumes only the number, not the "end of line". Primitive data types like int, double etc do not consume "end of line", therefore the "end of line" remains in buffer and When input.next() executes, it consumes the "end of line" from buffer from the first input. That's why, your String sentence = scanner.next() only consumes the "end of line" and does not wait to read from keyboard.

Tip: use scanner.nextLine() instead of scanner.next() because scanner.next() does not read white spaces from the keyboard. (Truncate the string after giving some space from keyboard, only show string before space.)

Single Form Hide on Startup

In the designer, set the form's Visible property to false. Then avoid calling Show() until you need it.

A better paradigm is to not create an instance of the form until you need it.

Find string between two substrings

This I posted before as code snippet in Daniweb:

# picking up piece of string between separators
# function using partition, like partition, but drops the separators
def between(left,right,s):
    before,_,a = s.partition(left)
    a,_,after = a.partition(right)
    return before,a,after

s = "bla bla blaa <a>data</a> lsdjfasdjöf (important notice) 'Daniweb forum' tcha tcha tchaa"
print between('<a>','</a>',s)
print between('(',')',s)
print between("'","'",s)

""" Output:
('bla bla blaa ', 'data', " lsdjfasdj\xc3\xb6f (important notice) 'Daniweb forum' tcha tcha tchaa")
('bla bla blaa <a>data</a> lsdjfasdj\xc3\xb6f ', 'important notice', " 'Daniweb forum' tcha tcha tchaa")
('bla bla blaa <a>data</a> lsdjfasdj\xc3\xb6f (important notice) ', 'Daniweb forum', ' tcha tcha tchaa')
"""

Create Windows service from executable

You can check out my small free utility for service create\edit\delete operations. Here is create example:

Go to Service -> Modify -> Create

enter image description here

Executable file (google drive): [Download]

Source code: [Download]

Blog post: [BlogLink]

Service editor class: WinServiceUtils.cs

No @XmlRootElement generated by JAXB

JAXBElement wrappers works for cases where no @XmlRootElement is generated by JAXB. These wrappers are available in ObjectFactory class generated by maven-jaxb2-plugin. For eg:

     public class HelloWorldEndpoint {
        @PayloadRoot(namespace = NAMESPACE_URI, localPart = "person")
        @ResponsePayload
        public JAXBElement<Greeting> sayHello(@RequestPayload JAXBElement<Person> request) {

        Person person = request.getValue();

        String greeting = "Hello " + person.getFirstName() + " " + person.getLastName() + "!";

        Greeting greet = new Greeting();
        greet.setGreeting(greeting);

        ObjectFactory factory = new ObjectFactory();
        JAXBElement<Greeting> response = factory.createGreeting(greet);
        return response;
      }
 }

How do I get the Git commit count?

This command returns count of commits grouped by committers:

git shortlog -s

Output:

14 John lennon
9  Janis Joplin

You may want to know that the -s argument is the contraction form of --summary.

Flexbox Not Centering Vertically in IE

Found a good solution what worked for me, check this link https://codepen.io/chriswrightdesign/pen/emQNGZ/?editors=1100 First, we add a parent div, second we change min-height:100% to min-height:100vh. It works like a charm.

// by having a parent with flex-direction:row, 
// the min-height bug in IE doesn't stick around.
.flashy-content-outer { 
    display:flex;
    flex-direction:row;
}
.flashy-content-inner {
    display:flex;
    flex-direction:column;
    justify-content:center;
    align-items:center;
    min-width:100vw;
    min-height:100vh;
    padding:20px;
    box-sizing:border-box;
}
.flashy-content {
    display:inline-block;
    padding:15px;
    background:#fff;
}  

How does Python return multiple values from a function?

Since the return statement in getName specifies multiple elements:

def getName(self):
   return self.first_name, self.last_name

Python will return a container object that basically contains them.

In this case, returning a comma separated set of elements creates a tuple. Multiple values can only be returned inside containers.

Let's use a simpler function that returns multiple values:

def foo(a, b):
    return a, b

You can look at the byte code generated by using dis.dis, a disassembler for Python bytecode. For comma separated values w/o any brackets, it looks like this:

>>> import dis
>>> def foo(a, b):
...     return a,b        
>>> dis.dis(foo)
  2           0 LOAD_FAST                0 (a)
              3 LOAD_FAST                1 (b)
              6 BUILD_TUPLE              2
              9 RETURN_VALUE

As you can see the values are first loaded on the internal stack with LOAD_FAST and then a BUILD_TUPLE (grabbing the previous 2 elements placed on the stack) is generated. Python knows to create a tuple due to the commas being present.

You could alternatively specify another return type, for example a list, by using []. For this case, a BUILD_LIST is going to be issued following the same semantics as it's tuple equivalent:

>>> def foo_list(a, b):
...     return [a, b]
>>> dis.dis(foo_list)
  2           0 LOAD_FAST                0 (a)
              3 LOAD_FAST                1 (b)
              6 BUILD_LIST               2
              9 RETURN_VALUE

The type of object returned really depends on the presence of brackets (for tuples () can be omitted if there's at least one comma). [] creates lists and {} sets. Dictionaries need key:val pairs.

To summarize, one actual object is returned. If that object is of a container type, it can contain multiple values giving the impression of multiple results returned. The usual method then is to unpack them directly:

>>> first_name, last_name = f.getName()
>>> print (first_name, last_name)

As an aside to all this, your Java ways are leaking into Python :-)

Don't use getters when writing classes in Python, use properties. Properties are the idiomatic way to manage attributes, for more on these, see a nice answer here.

Start an external application from a Google Chrome Extension?

There's an extension for Chrome (SimpleGet) that has a plugin for Windows and Linux that can execute an app with command line parameters.....
http://pinel.cc/
http://code.google.com/p/simple-get/
http://www.chromeextensions.org/other/simple-get/

The best way to remove duplicate values from NSMutableArray in Objective-C?

Using Orderedset will do the trick. This will keep the remove duplicates from the array and maintain order which sets normally doesn't do

Does it make sense to use Require.js with Angular.js?

Yes it makes sense to use requireJS with Angular, I spent several days to test several technical solutions.

I made an Angular Seed with RequireJS on Server Side. Very simple one. I use SHIM notation for no AMD module and not AMD because I think it's very difficult to deal with two different Dependency injection system.

I use grunt and r.js to concatenate js files on server depends on the SHIM configuration (dependency) file. So I refer only one js file in my app.

For more information go on my github Angular Seed : https://github.com/matohawk/angular-seed-requirejs

What is the best way to conditionally apply attributes in AngularJS?

Was able to get this working:

ng-attr-aria-current="{{::item.isSelected==true ? 'page' : undefined}}"

The nice thing here is that if item.isSelected is false then the attribute simply isn't rendered.

How to determine SSL cert expiration date from a PEM encoded certificate?

With openssl:

openssl x509 -enddate -noout -in file.pem

The output is on the form:

notAfter=Nov  3 22:23:50 2014 GMT

Also see MikeW's answer for how to easily check whether the certificate has expired or not, or whether it will within a certain time period, without having to parse the date above.

Placeholder in UITextView

Simple way to use this within some line of code:

Take one label up to UITextView in .nib connecting this label to your code , After it.

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{

    if (range.location>0 || text.length!=0) {
        placeholderLabel1.hidden = YES;
    }else{
        placeholderLabel1.hidden = NO;
    }
    return YES;
}

Execute Insert command and return inserted Id in Sql

Change the query to

"INSERT INTO Mem_Basic(Mem_Na,Mem_Occ) VALUES(@na,@occ); SELECT SCOPE_IDENTITY()"

This will return the last inserted ID which you can then get with ExecuteScalar

GCC dump preprocessor defines

Late answer - I found the other answers useful - and wanted to add a bit extra.


How do I dump preprocessor macros coming from a particular header file?

echo "#include <sys/socket.h>" | gcc -E -dM -

or (thanks to @mymedia for the suggestion):

gcc -E -dM -include sys/socket.h - < /dev/null

In particular, I wanted to see what SOMAXCONN was defined to on my system. I know I could just open up the standard header file, but sometimes I have to search around a bit to find the header file locations. Instead I can just use this one-liner:

$ gcc -E -dM -include sys/socket.h - < /dev/null | grep SOMAXCONN
#define SOMAXCONN 128
$ 

Access elements in json object like an array

var coordinates = [jsonObject[3][0], 
                   jsonObject[3][0],
                   jsonObject[4][1], 
                   jsonObject[4][1]];

How to convert a list into data table

private DataTable CreateDataTable(IList<T> item)
{
    Type type = typeof(T);
    var properties = type.GetProperties();

    DataTable dataTable = new DataTable();
    foreach (PropertyInfo info in properties)
    {
        dataTable.Columns.Add(new DataColumn(info.Name, Nullable.GetUnderlyingType(info.PropertyType) ?? info.PropertyType));
    }

    foreach (T entity in item)
    {
        object[] values = new object[properties.Length];
        for (int i = 0; i < properties.Length; i++)
        {
            values[i] = properties[i].GetValue(entity);
        }

        dataTable.Rows.Add(values);
    }
    return dataTable;
}

Apache: "AuthType not set!" 500 Error

I think that you have a version 2.4.x of Apache.

Have you sure that you load this 2 modules ? - mod_authn_core - mod_authz_core

LoadModule authn_core_module modules/mod_authn_core.so
LoadModule authz_core_module modules/mod_authz_core.so

PS : My recommendation for authorization and rights is (by default) :

LoadModule authn_file_module modules/mod_authn_file.so
LoadModule authn_core_module modules/mod_authn_core.so
LoadModule authz_host_module modules/mod_authz_host.so
LoadModule authz_groupfile_module modules/mod_authz_groupfile.so
LoadModule authz_user_module modules/mod_authz_user.so
LoadModule authz_core_module modules/mod_authz_core.so
LoadModule auth_basic_module modules/mod_auth_basic.so
LoadModule auth_digest_module modules/mod_auth_digest.so

How to pass an array into a function, and return the results with an array

Here is how I do it. This way I can actually get a function to simulate returning multiple values;

function foo($array) 
{ 
    foreach($array as $_key => $_value) 
    {
       $str .= "{$_key}=".$_value.'&';
    }
    return $str = substr($str, 0, -1);
} 

/* Set the variables to pass to function, in an Array */

    $waffles['variable1'] = "value1"; 
    $waffles['variable2'] = "value2"; 
    $waffles['variable3'] = "value3"; 

/* Call Function */

    parse_str( foo( $waffles ));

/* Function returns multiple variable/value pairs */

    echo $variable1 ."<br>";
    echo $variable2 ."<br>";
    echo $variable3 ."<br>";

Especially usefull if you want, for example all fields in a database to be returned as variables, named the same as the database table fields. See 'db_fields( )' function below.

For example, if you have a query

select login, password, email from members_table where id = $id

Function returns multiple variables:

$login, $password and $email

Here is the function:

function db_fields($field, $filter, $filter_by,  $table = 'members_table') {

 /*
    This function will return as variable names, all fields that you request, 
    and the field values assigned to the variables as variable values.  

    $filter_by = TABLE FIELD TO FILTER RESULTS BY
    $filter =  VALUE TO FILTER BY
    $table = TABLE TO RUN QUERY AGAINST

    Returns single string value or ARRAY, based on whether user requests single
    field or multiple fields.

    We return all fields as variable names. If multiple rows
    are returned, check is_array($return_field); If > 0, it contains multiple rows.
    In that case, simply run parse_str($return_value) for each Array Item. 
*/
    $field = ($field == "*") ? "*,*" : $field;
    $fields = explode(",",$field);

    $assoc_array = ( count($fields) > 0 ) ? 1 : 0;

    if (!$assoc_array) {
        $result = mysql_fetch_assoc(mysql_query("select $field from $table where $filter_by = '$filter'"));
        return ${$field} = $result[$field];
    }
    else
    {
        $query = mysql_query("select $field from $table where $filter_by = '$filter'");
        while ($row = mysql_fetch_assoc($query)) {
            foreach($row as $_key => $_value) {
                $str .= "{$_key}=".$_value.'&';
            }
            return $str = substr($str, 0, -1);
        }
    }
}

Below is a sample call to function. So, If we need to get User Data for say $user_id = 12345, from the members table with fields ID, LOGIN, PASSWORD, EMAIL:

$filter = $user_id;
$filter_by = "ID";
$table_name = "members_table"

parse_str(db_fields('LOGIN, PASSWORD, EMAIL', $filter, $filter_by, $table_name));

/* This will return the following variables: */

echo $LOGIN ."<br>";
echo $PASSWORD ."<br>";
echo $EMAIL ."<br>";

We could also call like this:

parse_str(db_fields('*', $filter, $filter_by, $table_name));

The above call would return all fields as variable names.

Is it possible only to declare a variable without assigning any value in Python?

If I'm understanding your example right, you don't need to refer to 'value' in the if statement anyway. You're breaking out of the loop as soon as it could be set to anything.

value = None
for index in sequence:
   doSomethingHere
   if conditionMet:
       value = index
       break 

Cleanest way to toggle a boolean variable in Java?

Unfortunately, there is no short form like numbers have increment/decrement:

i++;

I would like to have similar short expression to invert a boolean, dmth like:

isEmpty!;

ImportError: No module named 'bottle' - PyCharm

in your PyCharm project:

  • press Ctrl+Alt+s to open the settings
  • on the left column, select Project Interpreter
  • on the top right there is a list of python binaries found on your system, pick the right one
  • eventually click the + button to install additional python modules
  • validate

enter image description here

Pure JavaScript: a function like jQuery's isNumeric()

There is Javascript function isNaN which will do that.

isNaN(90)
=>false

so you can check numeric by

!isNaN(90)
=>true

Comparing two byte arrays in .NET

It seems that EqualBytesLongUnrolled is the best from the above suggested.

Skipped methods (Enumerable.SequenceEqual,StructuralComparisons.StructuralEqualityComparer.Equals), were not-patient-for-slow. On 265MB arrays I have measured this:

Host Process Environment Information:
BenchmarkDotNet.Core=v0.9.9.0
OS=Microsoft Windows NT 6.2.9200.0
Processor=Intel(R) Core(TM) i7-3770 CPU 3.40GHz, ProcessorCount=8
Frequency=3323582 ticks, Resolution=300.8802 ns, Timer=TSC
CLR=MS.NET 4.0.30319.42000, Arch=64-bit RELEASE [RyuJIT]
GC=Concurrent Workstation
JitModules=clrjit-v4.6.1590.0

Type=CompareMemoriesBenchmarks  Mode=Throughput  

                 Method |      Median |    StdDev | Scaled | Scaled-SD |
----------------------- |------------ |---------- |------- |---------- |
             NewMemCopy |  30.0443 ms | 1.1880 ms |   1.00 |      0.00 |
 EqualBytesLongUnrolled |  29.9917 ms | 0.7480 ms |   0.99 |      0.04 |
          msvcrt_memcmp |  30.0930 ms | 0.2964 ms |   1.00 |      0.03 |
          UnsafeCompare |  31.0520 ms | 0.7072 ms |   1.03 |      0.04 |
       ByteArrayCompare | 212.9980 ms | 2.0776 ms |   7.06 |      0.25 |

OS=Windows
Processor=?, ProcessorCount=8
Frequency=3323582 ticks, Resolution=300.8802 ns, Timer=TSC
CLR=CORE, Arch=64-bit ? [RyuJIT]
GC=Concurrent Workstation
dotnet cli version: 1.0.0-preview2-003131

Type=CompareMemoriesBenchmarks  Mode=Throughput  

                 Method |      Median |    StdDev | Scaled | Scaled-SD |
----------------------- |------------ |---------- |------- |---------- |
             NewMemCopy |  30.1789 ms | 0.0437 ms |   1.00 |      0.00 |
 EqualBytesLongUnrolled |  30.1985 ms | 0.1782 ms |   1.00 |      0.01 |
          msvcrt_memcmp |  30.1084 ms | 0.0660 ms |   1.00 |      0.00 |
          UnsafeCompare |  31.1845 ms | 0.4051 ms |   1.03 |      0.01 |
       ByteArrayCompare | 212.0213 ms | 0.1694 ms |   7.03 |      0.01 |

JAVA_HOME should point to a JDK not a JRE

I met the same problem. (Window 10 environment) I solved it by deleting the JAVA_HOME="C:\Program Files\Java\jdk1.8.0_161\bin" in the User Variables instead of adding to the System Variables directly.

Then I test that editing JAVA_HOME="C:\Program Files\Java\jdk1.8.0_161\" worked too. When I run "mvn -version" in command prompt window, it shows "Java home: C:\Program Files\Java\jdk1.8.0_161\jre".

In conclusion, I guess the JAVA_HOME shouldn't include bin directory.

Passing an array using an HTML form hidden element

Use:

$postvalue = array("a", "b", "c");
foreach($postvalue as $value)
{
    echo '<input type="hidden" name="result[]" value="'. $value. '">';
}

And you will get $_POST['result'] as an array.

print_r($_POST['result']);

retrieve links from web page using python and BeautifulSoup

For completeness sake, the BeautifulSoup 4 version, making use of the encoding supplied by the server as well:

from bs4 import BeautifulSoup
import urllib.request

parser = 'html.parser'  # or 'lxml' (preferred) or 'html5lib', if installed
resp = urllib.request.urlopen("http://www.gpsbasecamp.com/national-parks")
soup = BeautifulSoup(resp, parser, from_encoding=resp.info().get_param('charset'))

for link in soup.find_all('a', href=True):
    print(link['href'])

or the Python 2 version:

from bs4 import BeautifulSoup
import urllib2

parser = 'html.parser'  # or 'lxml' (preferred) or 'html5lib', if installed
resp = urllib2.urlopen("http://www.gpsbasecamp.com/national-parks")
soup = BeautifulSoup(resp, parser, from_encoding=resp.info().getparam('charset'))

for link in soup.find_all('a', href=True):
    print link['href']

and a version using the requests library, which as written will work in both Python 2 and 3:

from bs4 import BeautifulSoup
from bs4.dammit import EncodingDetector
import requests

parser = 'html.parser'  # or 'lxml' (preferred) or 'html5lib', if installed
resp = requests.get("http://www.gpsbasecamp.com/national-parks")
http_encoding = resp.encoding if 'charset' in resp.headers.get('content-type', '').lower() else None
html_encoding = EncodingDetector.find_declared_encoding(resp.content, is_html=True)
encoding = html_encoding or http_encoding
soup = BeautifulSoup(resp.content, parser, from_encoding=encoding)

for link in soup.find_all('a', href=True):
    print(link['href'])

The soup.find_all('a', href=True) call finds all <a> elements that have an href attribute; elements without the attribute are skipped.

BeautifulSoup 3 stopped development in March 2012; new projects really should use BeautifulSoup 4, always.

Note that you should leave decoding the HTML from bytes to BeautifulSoup. You can inform BeautifulSoup of the characterset found in the HTTP response headers to assist in decoding, but this can be wrong and conflicting with a <meta> header info found in the HTML itself, which is why the above uses the BeautifulSoup internal class method EncodingDetector.find_declared_encoding() to make sure that such embedded encoding hints win over a misconfigured server.

With requests, the response.encoding attribute defaults to Latin-1 if the response has a text/* mimetype, even if no characterset was returned. This is consistent with the HTTP RFCs but painful when used with HTML parsing, so you should ignore that attribute when no charset is set in the Content-Type header.

Multiplying across in a numpy array

Normal multiplication like you showed:

>>> import numpy as np
>>> m = np.array([[1,2,3],[4,5,6],[7,8,9]])
>>> c = np.array([0,1,2])
>>> m * c
array([[ 0,  2,  6],
       [ 0,  5, 12],
       [ 0,  8, 18]])

If you add an axis, it will multiply the way you want:

>>> m * c[:, np.newaxis]
array([[ 0,  0,  0],
       [ 4,  5,  6],
       [14, 16, 18]])

You could also transpose twice:

>>> (m.T * c).T
array([[ 0,  0,  0],
       [ 4,  5,  6],
       [14, 16, 18]])

Invalidating JSON Web Tokens

WITHOUT USING REFRESHING OF JWT...

2 scenarios of an attack come to mind. One is about compromised login credentials. And the other is an actual theft of JWT.

For compromised login credentials, when a new login happens, normally send the user an email notification. So, if the customer doesn't consent to being the one who logged in, they should be advised to do a reset of credentials, which should save to database/cache the date-time the password was last set (and set this too when user sets password during initial registration). Whenever a user action is being authorized, the date-time a user changed their password should be fetched from database/cache and compared to the date-time a given JWT was generated, and forbid the action for JWTs that were generated before the said date-time of credentials reset, hence essentially rendering such JWTs useless. That means save the date-time of generation of a JWT as a claim in the JWT itself. In ASP.NET Core, a policy/requirement can be used to do do this comparison, and on failure, the client is forbidden. This consequently logs out the user on the backend, globally, whenever a reset of credentials is done.

For actual theft of JWT... A theft of JWT is not easy to detect but a JWT that expires easily solves this. But what can be done to stop the attacker before the JWT expires? It is with an actual global logout. It is similar to what was described above for credentials reset. For this, normally save on database/cache the date-time a user initiated a global logout, and on authorizing a user action, get it and compare it to the date-time of generation of a given JWT too, and forbid the action for JWTs that were generated before the said date-time of global logout, hence essentially rendering such JWTs useless. This can be done using a policy/requirement in ASP.NET Core, as previously described.

Now, how do you detect the theft of JWT? My answer to this for now is to occasionally alert user to globally log out and log in again, as this would definitely log the attacker out.

How to use Tomcat 8 in Eclipse?

UPDATE: Eclipse Mars EE and later have native support for Tomcat8. Use this only if you have an earlier version of eclipse.


The latest version of Eclipse still does not support Tomcat 8, but you can add the new version of WTP and Tomcat 8 support will be added natively. To do this:

  • Download the latest version of Eclipse for Java EE
  • Go to the WTP downloads page, select the latest version (currently 3.6), and download the zip (under Traditional Zip Files...Web App Developers). Here's the current link.
  • Copy the all of the files in features and plugins directories of the downloaded WTP into the corresponding Eclipse directories in your Eclipse folder (overwriting the existing files).

Start Eclipse and you should have a Tomcat 8 option available when you go to deploy. enter image description here

Android Drawing Separator/Divider Line in Layout?

Adding this view; that draws a separator between your textviews

<View
    android:layout_width="match_parent"
    android:layout_height="1dp"
    android:background="#000000" />

Use Excel pivot table as data source for another Pivot Table

  • Make your first pivot table.

  • Select the first top left cell.

  • Create a range name using offset:

    OFFSET(Sheet1!$A$3,0,0,COUNTA(Sheet1!$A:$A)-1,COUNTA(Sheet1!$3:$3))

  • Make your second pivot with your range name as source of data using F3.

If you change number of rows or columns from your first pivot, your second pivot will be update after refreshing pivot

GFGDT

Large WCF web service request failing with (400) HTTP Bad Request

In the server in .NET 4.0 in web.config you also need to change in the default binding. Set the follwowing 3 parms:

 < basicHttpBinding>  
   < !--http://www.intertech.com/Blog/post/NET-40-WCF-Default-Bindings.aspx  
    - Enable transfer of large strings with maxBufferSize, maxReceivedMessageSize and maxStringContentLength
    -->  
   < binding **maxBufferSize="2147483647" maxReceivedMessageSize="2147483647"**>  
      < readerQuotas **maxStringContentLength="2147483647"**/>            
   < /binding>

Formatting Numbers by padding with leading zeros in SQL Server

Change the number 6 to whatever your total length needs to be:

SELECT REPLICATE('0',6-LEN(EmployeeId)) + EmployeeId

If the column is an INT, you can use RTRIM to implicitly convert it to a VARCHAR

SELECT REPLICATE('0',6-LEN(RTRIM(EmployeeId))) + RTRIM(EmployeeId)

And the code to remove these 0s and get back the 'real' number:

SELECT RIGHT(EmployeeId,(LEN(EmployeeId) - PATINDEX('%[^0]%',EmployeeId)) + 1)

how do I join two lists using linq or lambda expressions

It sounds like you want something like:

var query = from order in workOrders
            join plan in plans
                 on order.WorkOrderNumber equals plan.WorkOrderNumber
            select new
            {
                order.WorkOrderNumber,
                order.Description,
                plan.ScheduledDate
            };

Android Service needs to run always (Never pause or stop)

Add this in manifest.

      <service
        android:name=".YourServiceName"
        android:enabled="true"
        android:exported="false" />

Add a service class.

public class YourServiceName extends Service {


    @Override
    public void onCreate() {
        super.onCreate();

      // Timer task makes your service will repeat after every 20 Sec.
       TimerTask doAsynchronousTask = new TimerTask() {
            @Override
            public void run() {
                handler.post(new Runnable() {
                    public void run() {
                       // Add your code here.

                     }

               });
            }
        };
  //Starts after 20 sec and will repeat on every 20 sec of time interval.
        timer.schedule(doAsynchronousTask, 20000,20000);  // 20 sec timer 
                              (enter your own time)
    }
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // TODO do something useful

      return START_STICKY;
    }

}

Ternary operator in AngularJS templates

  <body ng-app="app">
  <button type="button" ng-click="showme==true ? !showme :showme;message='Cancel Quiz'"  class="btn btn-default">{{showme==true ? 'Cancel Quiz': 'Take a Quiz'}}</button>
    <div ng-show="showme" class="panel panel-primary col-sm-4" style="margin-left:250px;">
      <div class="panel-heading">Take Quiz</div>
      <div class="form-group col-sm-8 form-inline" style="margin-top: 30px;margin-bottom: 30px;">

        <button type="button" class="btn btn-default">Start Quiz</button>
      </div>
    </div>
  </body>

Button toggle and change header of button and show/hide div panel. See the Plunkr

How to Flatten a Multidimensional Array?

You can do it with ouzo goodies:

 $result = Arrays::flatten($multidimensional);

See: Here

PHP foreach with Nested Array?

If you know the number of levels in nested arrays you can simply do nested loops. Like so:

//  Scan through outer loop
foreach ($tmpArray as $innerArray) {
    //  Check type
    if (is_array($innerArray)){
        //  Scan through inner loop
        foreach ($innerArray as $value) {
            echo $value;
        }
    }else{
        // one, two, three
        echo $innerArray;
    }
}

if you do not know the depth of array you need to use recursion. See example below:

//  Multi-dementional Source Array
$tmpArray = array(
    array("one", array(1, 2, 3)),
    array("two", array(4, 5, 6)),
    array("three", array(
            7,
            8,
            array("four", 9, 10)
    ))
);

//  Output array
displayArrayRecursively($tmpArray);

/**
 * Recursive function to display members of array with indentation
 *
 * @param array $arr Array to process
 * @param string $indent indentation string
 */
function displayArrayRecursively($arr, $indent='') {
    if ($arr) {
        foreach ($arr as $value) {
            if (is_array($value)) {
                //
                displayArrayRecursively($value, $indent . '--');
            } else {
                //  Output
                echo "$indent $value \n";
            }
        }
    }
}

The code below with display only nested array with values for your specific case (3rd level only)

$tmpArray = array(
    array("one", array(1, 2, 3)),
    array("two", array(4, 5, 6)),
    array("three", array(7, 8, 9))
);

//  Scan through outer loop
foreach ($tmpArray as $inner) {

    //  Check type
    if (is_array($inner)) {
        //  Scan through inner loop
        foreach ($inner[1] as $value) {
           echo "$value \n";
        }
    }
}

'No database provider has been configured for this DbContext' on SignInManager.PasswordSignInAsync

Override constructor of DbContext Try this :-

public DataContext(DbContextOptions<DataContext> option):base(option) {}

how to check if the input is a number or not in C?

I was struggling with this for awhile, so I thought I'd just add my two cents:

1) Create a separate function to check if an fgets input consists entirely of numbers:

int integerCheck(){
char myInput[4];
fgets(myInput, sizeof(myInput), stdin);
    int counter = 0;
    int i;
    for (i=0; myInput[i]!= '\0'; i++){
        if (isalpha(myInput[i]) != 0){
            counter++;
            if(counter > 0){
                printf("Input error: Please try again. \n ");
                return main();
            }
        }

    }
    return atoi(myInput); 
}

The above starts a loop through every unit of an fgets input until the ending NULL value. If it comes across a letter or an operator, it adds "1" to the int "counter" which is initially set to 0. Once the counter becomes greater than 0, the nested if statement instructs the loop to print an error message & then restart the program. When the loops completes, if int 'counter' is still the value of 0, it returns the initially inputted integer to be used in the main function ...

2) the main function would be:

int main(void){
unsigned int numberOne;
unsigned int numberTwo;
numberOne = integerCheck();
numberTwo = integerCheck();
return numberOne*numberTwo;

}

Assuming both integers are inputted correctly, the example provided will yield the result of int "numberOne" multiplied by int "numberTwo". The program will repeat for however long it takes to get two properly inputted integers.

Neither BindingResult nor plain target object for bean name available as request attribute

In the controller, you need to add the login object as an attribute of the model:

model.addAttribute("login", new Login());

Like this:

@RequestMapping(value = "/", method = RequestMethod.GET) 
public String displayLogin(Model model) { 
    model.addAttribute("login", new Login()); 
    return "login"; 
}

Change class on mouseover in directive

This is my solution for my scenario:

<div class="btn-group btn-group-justified">
    <a class="btn btn-default" ng-class="{'btn-success': hover.left, 'btn-danger': hover.right}" ng-click="setMatch(-1)" role="button" ng-mouseenter="hover.left = true;" ng-mouseleave="hover.left = false;">
        <i class="fa fa-thumbs-o-up fa-5x pull-left" ng-class="{'fa-rotate-90': !hover.left && !hover.right, 'fa-flip-vertical': hover.right}"></i>
        {{ song.name }}
    </a>
    <a class="btn btn-default" ng-class="{'btn-success': hover.right, 'btn-danger': hover.left}" ng-click="setMatch(1)" role="button" ng-mouseenter="hover.right = true;" ng-mouseleave="hover.right = false;">
        <i class="fa fa-thumbs-o-up fa-5x pull-right" ng-class="{'fa-rotate-270': !hover.left && !hover.right, 'fa-flip-vertical': hover.left}"></i>
        {{ match.name }}
    </a>
</div>

default state: enter image description here

on hover: enter image description here

Webclient / HttpWebRequest with Basic Authentication returns 404 not found for valid URL

//BEWARE
//This works ONLY if the server returns 401 first
//The client DOES NOT send credentials on first request
//ONLY after a 401
client.Credentials = new NetworkCredential(userName, passWord); //doesnt work

//So use THIS instead to send credentials RIGHT AWAY
string credentials = Convert.ToBase64String(
    Encoding.ASCII.GetBytes(userName + ":" + password));
client.Headers[HttpRequestHeader.Authorization] = string.Format(
    "Basic {0}", credentials);

Get the IP Address of local computer

I was able to do it using DNS service under VS2013 with the following code:

#include <Windns.h>

WSADATA wsa_Data;

int wsa_ReturnCode = WSAStartup(0x101, &wsa_Data);

gethostname(hostName, 256);
PDNS_RECORD pDnsRecord;

DNS_STATUS statsus = DnsQuery(hostName, DNS_TYPE_A, DNS_QUERY_STANDARD, NULL, &pDnsRecord, NULL);
IN_ADDR ipaddr;
ipaddr.S_un.S_addr = (pDnsRecord->Data.A.IpAddress);
printf("The IP address of the host %s is %s \n", hostName, inet_ntoa(ipaddr));

DnsRecordListFree(&pDnsRecord, DnsFreeRecordList);

I had to add Dnsapi.lib as addictional dependency in linker option.

Reference here.

Implementing a HashMap in C

The primary goal of a hashmap is to store a data set and provide near constant time lookups on it using a unique key. There are two common styles of hashmap implementation:

  • Separate chaining: one with an array of buckets (linked lists)
  • Open addressing: a single array allocated with extra space so index collisions may be resolved by placing the entry in an adjacent slot.

Separate chaining is preferable if the hashmap may have a poor hash function, it is not desirable to pre-allocate storage for potentially unused slots, or entries may have variable size. This type of hashmap may continue to function relatively efficiently even when the load factor exceeds 1.0. Obviously, there is extra memory required in each entry to store linked list pointers.

Hashmaps using open addressing have potential performance advantages when the load factor is kept below a certain threshold (generally about 0.7) and a reasonably good hash function is used. This is because they avoid potential cache misses and many small memory allocations associated with a linked list, and perform all operations in a contiguous, pre-allocated array. Iteration through all elements is also cheaper. The catch is hashmaps using open addressing must be reallocated to a larger size and rehashed to maintain an ideal load factor, or they face a significant performance penalty. It is impossible for their load factor to exceed 1.0.

Some key performance metrics to evaluate when creating a hashmap would include:

  • Maximum load factor
  • Average collision count on insertion
  • Distribution of collisions: uneven distribution (clustering) could indicate a poor hash function.
  • Relative time for various operations: put, get, remove of existing and non-existing entries.

Here is a flexible hashmap implementation I made. I used open addressing and linear probing for collision resolution.

https://github.com/DavidLeeds/hashmap

Correct way to pause a Python program

In Linux, you can issue kill -TSTP <pid> to the background and stop a process. So, it's there, but not consuming CPU time.

Then later, kill -CONT <pid> and it's off and running again.

How to use absolute path in twig functions

Daniel's answer seems to work fine for now, but please note that generating absolute urls using twig's asset function is now deprecated:

DEPRECATED - Generating absolute URLs with the Twig asset() function was deprecated in 2.7 and will be removed in 3.0. Please use absolute_url() instead.

Here's the official announcement: http://symfony.com/blog/new-in-symfony-2-7-the-new-asset-component#template-function-changes

You have to use the absolute_url twig function:

{# Symfony 2.6 #}
{{ asset('logo.png', absolute = true) }}

{# Symfony 2.7 #}
{{ absolute_url(asset('logo.png')) }}

It is interesting to note that it also works with path function:

{{ absolute_url(path('index')) }}

Java getHours(), getMinutes() and getSeconds()

Java 8

    System.out.println(LocalDateTime.now().getHour());       // 7
    System.out.println(LocalDateTime.now().getMinute());     // 45
    System.out.println(LocalDateTime.now().getSecond());     // 32

Calendar

System.out.println(Calendar.getInstance().get(Calendar.HOUR_OF_DAY));  // 7 
System.out.println(Calendar.getInstance().get(Calendar.MINUTE));       // 45
System.out.println(Calendar.getInstance().get(Calendar.SECOND));       // 32

Joda Time

    System.out.println(new DateTime().getHourOfDay());      // 7
    System.out.println(new DateTime().getMinuteOfHour());   // 45
    System.out.println(new DateTime().getSecondOfMinute()); // 32

Formatted

Java 8

    // 07:48:55.056
    System.out.println(ZonedDateTime.now().format(DateTimeFormatter.ISO_LOCAL_TIME));
    // 7:48:55
    System.out.println(LocalTime.now().getHour() + ":" + LocalTime.now().getMinute() + ":" + LocalTime.now().getSecond());

    // 07:48:55
    System.out.println(new SimpleDateFormat("HH:mm:ss").format(Calendar.getInstance().getTime()));

    // 074855
    System.out.println(new SimpleDateFormat("HHmmss").format(Calendar.getInstance().getTime()));

    // 07:48:55 
    System.out.println(new Date().toString().substring(11, 20));

Get counts of all tables in a schema

This should do it:

declare
    v_count integer;
begin

    for r in (select table_name, owner from all_tables
              where owner = 'SCHEMA_NAME') 
    loop
        execute immediate 'select count(*) from ' || r.table_name 
            into v_count;
        INSERT INTO STATS_TABLE(TABLE_NAME,SCHEMA_NAME,RECORD_COUNT,CREATED)
        VALUES (r.table_name,r.owner,v_count,SYSDATE);
    end loop;

end;

I removed various bugs from your code.

Note: For the benefit of other readers, Oracle does not provide a table called STATS_TABLE, you would need to create it.

What is the simplest way to swap each pair of adjoining chars in a string with Python?

Loop over length of string by twos and swap:

def oddswap(st):
    s = list(st)
    for c in range(0,len(s),2):
        t=s[c]
        s[c]=s[c+1]
        s[c+1]=t

    return "".join(s)

giving:

>>> s
'foobar'
>>> oddswap(s)
'ofbora'

and fails on odd-length strings with an IndexError exception.

Object of class mysqli_result could not be converted to string in

mysqli:query() returns a mysqli_result object, which cannot be serialized into a string.

You need to fetch the results from the object. Here's how to do it.

If you need a single value.

Fetch a single row from the result and then access column index 0 or using an associative key. Use the null-coalescing operator in case no rows are present in the result.

$result = $con->query($tourquery);  // or mysqli_query($con, $tourquery);

$tourresult = $result->fetch_array()[0] ?? '';
// OR
$tourresult = $result->fetch_array()['roomprice'] ?? '';

echo '<strong>Per room amount:  </strong>'.$tourresult;

If you need multiple values.

Use foreach loop to iterate over the result and fetch each row one by one. You can access each column using the column name as an array index.

$result = $con->query($tourquery);  // or mysqli_query($con, $tourquery);

foreach($result as $row) {
    echo '<strong>Per room amount:  </strong>'.$row['roomprice'];
}

How to install XNA game studio on Visual Studio 2012?

I found another issue, for some reason if the extensions are cached in the local AppData folder, the XNA extensions never get loaded.

You need to remove the files extensionSdks.en-US.cache and extensions.en-US.cache from the %LocalAppData%\Microsoft\VisualStudio\11.0\Extensions folder. These files are rebuilt the next time you launch

If you need access to the Visual Studio startup log to debug what's happening, run devenv.exe /log command from the C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE directory (assuming you are on a 64 bit machine). The log file generated is located here:

%AppData%\Microsoft\VisualStudio\11.0\ActivityLog.xml

Null vs. False vs. 0 in PHP

False, Null, Nothing, 0, Undefined, etc., etc.

Each of these has specific meanings that correlate with actual concepts. Sometimes multiple meanings are overloaded into a single keyword or value.

In C and C++, NULL, False and 0 are overloaded to the same value. In C# they're 3 distinct concepts.

null or NULL usually indicates a lack of value, but usually doesn't specify why. 0 indicates the natural number zero and has type-equivalence to 1, 2, 3, etc. and in languages that support separate concepts of NULL should be treated only a number.

False indicates non-truth. And it used in binary values. It doesn't mean unset, nor does it mean 0. It simply indicates one of two binary values.

Nothing can indicate that the value is specifically set to be nothing which indicates the same thing as null, but with intent.

Undefined in some languages indicates that the value has yet to be set because no code has specified an actual value.

How do I revert a Git repository to a previous commit?

The best way is:

git reset --hard <commidId> && git push --force

This will reset the branch to the specific commit and then will upload the remote server with the same commits as you have in local.

Be careful with the --force flag as it removes all the subsequent commits after the selected commit without the option to recover them.

How to open generated pdf using jspdf in new window

Based on the source you can use the 'dataurlnewwindow' parameter for output():

doc.output('dataurlnewwindow');

Source in github: https://github.com/MrRio/jsPDF/blob/master/jspdf.js#L914

All possible cases:

doc.output('save', 'filename.pdf'); //Try to save PDF as a file (not works on ie before 10, and some mobile devices)
doc.output('datauristring');        //returns the data uri string
doc.output('datauri');              //opens the data uri in current window
doc.output('dataurlnewwindow');     //opens the data uri in new window

Count(*) vs Count(1) - SQL Server

COUNT(*) and COUNT(1) are same in case of result and performance.

Simple CSS Animation Loop – Fading In & Out "Loading" Text

As King King said, you must add the browser specific prefix. This should cover most browsers:

_x000D_
_x000D_
@keyframes flickerAnimation {_x000D_
  0%   { opacity:1; }_x000D_
  50%  { opacity:0; }_x000D_
  100% { opacity:1; }_x000D_
}_x000D_
@-o-keyframes flickerAnimation{_x000D_
  0%   { opacity:1; }_x000D_
  50%  { opacity:0; }_x000D_
  100% { opacity:1; }_x000D_
}_x000D_
@-moz-keyframes flickerAnimation{_x000D_
  0%   { opacity:1; }_x000D_
  50%  { opacity:0; }_x000D_
  100% { opacity:1; }_x000D_
}_x000D_
@-webkit-keyframes flickerAnimation{_x000D_
  0%   { opacity:1; }_x000D_
  50%  { opacity:0; }_x000D_
  100% { opacity:1; }_x000D_
}_x000D_
.animate-flicker {_x000D_
   -webkit-animation: flickerAnimation 1s infinite;_x000D_
   -moz-animation: flickerAnimation 1s infinite;_x000D_
   -o-animation: flickerAnimation 1s infinite;_x000D_
    animation: flickerAnimation 1s infinite;_x000D_
}
_x000D_
<div class="animate-flicker">Loading...</div>
_x000D_
_x000D_
_x000D_

getaddrinfo: nodename nor servname provided, or not known

The error occurs when the DNS resolution fails. Check if you can wget (or curl) the api url from the command line. Changing the DNS server and testing it might help.

Razor/CSHTML - Any Benefit over what we have?

Ex Microsoft Developer's Opinion

I worked on a core team for the MSDN website. Now, I use c# razor for ecommerce sites with my programming team and we focus heavy on jQuery front end with back end c# razor pages and LINQ-Entity memory database so the pages are 1-2 millisecond response times even on nested for loops with queries and no page caching. We don't use MVC, just plain ASP.NET with razor pages being mapped with URL Rewrite module for IIS 7, no ASPX pages or ViewState or server-side event programming at all. It doesn't have the extra (unnecessary) layers MVC puts in code constructs for the regex challenged. Less is more for us. Its all lean and mean but I give props to MVC for its testability but that's all.

Razor pages have no event life cycle like ASPX pages. Its just rendering as one requested page. C# is such a great language and Razor gets out of its way nicely to let it do its job. The anonymous typing with generics and linq make life so easy with c# and razor pages. Using Razor pages will help you think and code lighter.

One of the drawback of Razor and MVC is there is no ViewState-like persistence. I needed to implement a solution for that so I ended up writing a jQuery plugin for that here -> http://www.jasonsebring.com/dumbFormState which is an HTML 5 offline storage supported plugin for form state that is working in all major browsers now. It is just for form state currently but you can use window.sessionStorage or window.localStorage very simply to store any kind of state across postbacks or even page requests, I just bothered to make it autosave and namespace it based on URL and form index so you don't have to think about it.

ERROR 1064 (42000): You have an error in your SQL syntax;

Try this:

Use back-ticks for NAME

CREATE TABLE `teachers` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `name` varchar(50) NOT NULL,
  `addr` varchar(255) NOT NULL,
  `phone` int(10) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

How to create Windows EventLog source from command line?

Try "eventcreate.exe"

An example:

eventcreate /ID 1 /L APPLICATION /T INFORMATION  /SO MYEVENTSOURCE /D "My first log"

This will create a new event source named MYEVENTSOURCE under APPLICATION event log as INFORMATION event type.

I think this utility is included only from XP onwards.

Further reading

What is an NP-complete in computer science?

As far as I understand

P is the set of problems which could be solved in polynomial time with a deterministic TM.

NP is the set of problems which requires a non-deterministic TM to be solved in polynomial time. This means that we can check all different combinations of variables in parallel with each instance taking polynomial time. If the problem is solvable then at least one of those parallel instances of TM would halt with "yes". This also means that if you could make a correct guess about the variables/solution then you just need to check it's validity in polynomial time.

NP-Hard is the set where problems are at least as hard as NP. This means NP-Hard problem are equally or more difficult than any problem in NP set.

  1. Example of a NP-hard problem which is more difficult than NP is the halting problem.
  2. Example of a NP-hard problem which is equally difficult to a NP problem is any problem in NP-Complete set (see below).

NP-Complete is the intersection set of NP and NP-Hard. A problems in NP-Complete set can be reduced to any other NP-Complete problem. That means if any of the NP-Complete problem would have an efficient solution then all of the NP-Complete problems could be solved with same solution.

How can you prove P=NP and win a US $1,000,000 prize?
If you could show that every NP problem is reducible to any other NP problem, then NP-Complete set spans over entire NP sets (definition of NP-Complete), i.e NP-Complete=NP. Also since P?NP, this means that at least one of those NP-Complete problem is solvable in polynomial time, which implies that entire NP set can be solved in polynomial time. Clearly it would conclude that P=NP. Well this is just one way to prove P=NP, there might be many other ways.

Please let me know if I made any mistake.

Clear data in MySQL table with PHP?

TRUNCATE will blank your table and reset primary key DELETE will also make your table blank but it will not reset primary key.

we can use for truncate

TRUNCATE TABLE tablename

we can use for delete

DELETE FROM tablename

we can also give conditions as below

DELETE FROM tablename WHERE id='xyz'

How do I create a link using javascript?

<html>
  <head></head>
  <body>
    <script>
      var a = document.createElement('a');
      var linkText = document.createTextNode("my title text");
      a.appendChild(linkText);
      a.title = "my title text";
      a.href = "http://example.com";
      document.body.appendChild(a);
    </script>
  </body>
</html>

const to Non-const Conversion in C++

Changing a constant type will lead to an Undefined Behavior.

However, if you have an originally non-const object which is pointed to by a pointer-to-const or referenced by a reference-to-const then you can use const_cast to get rid of that const-ness.

Casting away constness is considered evil and should not be avoided. You should consider changing the type of the pointers you use in vector to non-const if you want to modify the data through it.

Using ExcelDataReader to read Excel data starting from a particular cell

If you are using ExcelDataReader 3+ you will find that there isn't any method for AsDataSet() for your reader object, You need to also install another package for ExcelDataReader.DataSet, then you can use the AsDataSet() method.
Also there is not a property for IsFirstRowAsColumnNames instead you need to set it inside of ExcelDataSetConfiguration.

Example:

using (var stream = File.Open(originalFileName, FileMode.Open, FileAccess.Read))
{
    IExcelDataReader reader;

    // Create Reader - old until 3.4+
    ////var file = new FileInfo(originalFileName);
    ////if (file.Extension.Equals(".xls"))
    ////    reader = ExcelDataReader.ExcelReaderFactory.CreateBinaryReader(stream);
    ////else if (file.Extension.Equals(".xlsx"))
    ////    reader = ExcelDataReader.ExcelReaderFactory.CreateOpenXmlReader(stream);
    ////else
    ////    throw new Exception("Invalid FileName");
    // Or in 3.4+ you can only call this:
    reader = ExcelDataReader.ExcelReaderFactory.CreateReader(stream)

    //// reader.IsFirstRowAsColumnNames
    var conf = new ExcelDataSetConfiguration
    {
        ConfigureDataTable = _ => new ExcelDataTableConfiguration
        {
            UseHeaderRow = true 
        }
    };

    var dataSet = reader.AsDataSet(conf);

    // Now you can get data from each sheet by its index or its "name"
    var dataTable = dataSet.Tables[0];

    //...
}

You can find row number and column number of a cell reference like this:

var cellStr = "AB2"; // var cellStr = "A1";
var match = Regex.Match(cellStr, @"(?<col>[A-Z]+)(?<row>\d+)");
var colStr = match.Groups["col"].ToString();
var col = colStr.Select((t, i) => (colStr[i] - 64) * Math.Pow(26, colStr.Length - i - 1)).Sum();
var row = int.Parse(match.Groups["row"].ToString());

Now you can use some loops to read data from that cell like this:

for (var i = row; i < dataTable.Rows.Count; i++)
{
    for (var j = col; j < dataTable.Columns.Count; j++)
    {
        var data = dataTable.Rows[i][j];
    }
}

Update:

You can filter rows and columns of your Excel sheet at read time with this config:

var i = 0;
var conf = new ExcelDataSetConfiguration
{
    UseColumnDataType = true,
    ConfigureDataTable = _ => new ExcelDataTableConfiguration
    {
        FilterRow = rowReader => fromRow <= ++i - 1,
        FilterColumn = (rowReader, colIndex) => fromCol <= colIndex,
        UseHeaderRow = true
    }
};

LogCat message: The Google Play services resources were not found. Check your project configuration to ensure that the resources are included

LE: I just remembered this was about using Google Maps, so my answer doesn't really answer the initial question, but I hope some people will save hours/days banging their heads on their desks if they have the same issue with Play Game Services.

I too had this incredibly cryptic error. It wasn't anything related to location services for me, but with not properly reading the documentation, more precisely step 3, where it says to add the following to your AndroidManifest.xml:

<meta-data android:name="com.google.android.gms.games.APP_ID"
    android:value="@string/app_id" />

You should obviously also have the following in AndroidManifest.xml

<meta-data android:name="com.google.android.gms.version"
   android:value="@integer/google_play_services_version"/>

I was using the BaseGameActivity they suggest to use when you want to implement game services so I was a bit surprised it didn't work straight away. I did create a dedicated module for a copy of the google-play-services_lib, I did have the latest version of it (4323000 as of writing) and I did set this as a module dependency to my main module (using Android Studio here). But that little line above fixed everything.

How to place Text and an Image next to each other in HTML?

You want to use css float for this, you can put it directly in your code.

<body>
<img src="website_art.png" height= "75" width="235" style="float:left;"/>
<h3 style="float:right;">The Art of Gaming</h3>
</body>

But I would really suggest learning the basics of css and splitting all your styling out to a separate style sheet, and use classes. It will help you in the future. A good place to start is w3schools or, perhaps later down the path, Mozzila Dev. Network (MDN).

HTML:

<body>
  <img src="website_art.png" class="myImage"/>
  <h3 class="heading">The Art of Gaming</h3>
</body>

CSS:

.myImage {
  float: left;
  height: 75px;
  width: 235px;
  font-family: Veranda;
}
.heading {
  float:right;
}

Pandas DataFrame column to list

The above solution is good if all the data is of same dtype. Numpy arrays are homogeneous containers. When you do df.values the output is an numpy array. So if the data has int and float in it then output will either have int or float and the columns will loose their original dtype. Consider df

a  b 
0  1  4
1  2  5 
2  3  6 

a    float64
b    int64 

So if you want to keep original dtype, you can do something like

row_list = df.to_csv(None, header=False, index=False).split('\n')

this will return each row as a string.

['1.0,4', '2.0,5', '3.0,6', '']

Then split each row to get list of list. Each element after splitting is a unicode. We need to convert it required datatype.

def f(row_str): 
  row_list = row_str.split(',')
  return [float(row_list[0]), int(row_list[1])]

df_list_of_list = map(f, row_list[:-1])

[[1.0, 4], [2.0, 5], [3.0, 6]]

Determine a string's encoding in C#

It depends where the string 'came from'. A .NET string is Unicode (UTF-16). The only way it could be different if you, say, read the data from a database into a byte array.

This CodeProject article might be of interest: Detect Encoding for in- and outgoing text

Jon Skeet's Strings in C# and .NET is an excellent explanation of .NET strings.

Strip all non-numeric characters from string in JavaScript

Use the string's .replace method with a regex of \D, which is a shorthand character class that matches all non-digits:

myString = myString.replace(/\D/g,'');

Parsing Query String in node.js

require('url').parse('/status?name=ryan', {parseQueryString: true}).query

returns

{ name: 'ryan' }

ref: https://nodejs.org/api/url.html#url_urlobject_query

Bootstrap modal - close modal when "call to action" button is clicked

Use data-dismiss="modal". In the version of Bootstrap I am using v3.3.5, when data-dismiss="modal" is added to the desired button like shown below it calls my external Javascript (JQuery) function beautifully and magically closes the modal. Its soo Sweet, I was worried I would have to call some modal hide in another function and chain that to the real working function

 <a href="#" id="btnReleaseAll" class="btn btn-primary btn-default btn-small margin-right pull-right" data-dismiss="modal">Yes</a>

In some external script file, and in my doc ready there is of course a function for the click of that identifier ID

 $("#divExamListHeader").on('click', '#btnReleaseAll', function () {
               // Do DatabaseMagic Here for a call a MVC ActionResult

Hiding table data using <div style="display:none">

Give all the rows you want to hide a class name that you can use for hiding. Use javascript to add/remove this class from the different rows.

<table>
<tr><th>Test Table</th><tr>
<tr class="toHide"><td>123456789</td><tr>
<tr class="toHide"><td>123456789</td><tr>
<tr class="toHide"><td>123456789</td><tr>
</table>

CSS:

.toHide
{
 display: none;
}

react-native: command not found

If for some strange reasons, the path to react-native is not in the PATH, you should take note where the react-native executable is installed. Generally, the issue with command not found is because they are not in PATH.

For example, I use nodenv and run npm install -g react-native

/Users/khoa/.nodenv/versions/10.10.0/bin/react-native -> /Users/khoa/.nodenv/versions/10.10.0/lib/node_modules/react-native/local-cli/wrong-react-native.js

So I need to add that to my PATH

export PATH=$HOME/.nodenv/versions/10.10.0/bin:$PATH

You can verify with echo $PATH

Or you can use npx to execute local npm modules, for example

npx react-native run-ios --simulator='iPhone X'

Clicking HTML 5 Video element to play, pause video, breaks play button

Not to bring up an old post but I landed on this question in my search for the same solution. I ended up coming up with something of my own. Figured I'd contribute.

HTML:

<video class="video"><source src=""></video>

JAVASCRIPT: "JQUERY"

$('.video').click(function(){this.paused?this.play():this.pause();});

Are members of a C++ struct initialized to 0 by default?

Since this is a POD (essentially a C struct) there is little harm in initialising it the C way:

Snapshot s;
memset(&s, 0, sizeof (s));

or similarly

Snapshot *sp = new Snapshot;
memset(sp, 0, sizeof (*sp));

I wouldn't go so far as to use calloc() in a C++ program though.

What is difference between sjlj vs dwarf vs seh?

SJLJ (setjmp/longjmp): – available for 32 bit and 64 bit – not “zero-cost”: even if an exception isn’t thrown, it incurs a minor performance penalty (~15% in exception heavy code) – allows exceptions to traverse through e.g. windows callbacks

DWARF (DW2, dwarf-2) – available for 32 bit only – no permanent runtime overhead – needs whole call stack to be dwarf-enabled, which means exceptions cannot be thrown over e.g. Windows system DLLs.

SEH (zero overhead exception) – will be available for 64-bit GCC 4.8.

source: https://wiki.qt.io/MinGW-64-bit

How to prevent the "Confirm Form Resubmission" dialog?

You could try using AJAX calls with jQuery. Like how youtube adds your comment without refreshing. This would remove the problem with refreshing overal.

You'd need to send the info necessary trough the ajax call.
I'll use the youtube comment as example.

$.ajax({
    type: 'POST',
    url: 'ajax/comment-on-video.php',
    data: {
        comment: $('#idOfInputField').val();
     },
    success: function(obj) {
        if(obj === 'true') {
            //Some code that recreates the inserted comment on the page.
        }
    }
});

You can now create the file comment-on-video.php and create something like this:

<?php
    session_start();

    if(isset($_POST['comment'])) {
        $comment = mysqli_real_escape_string($db, $_POST['comment']);
        //Given you are logged in and store the user id in the session.
        $user = $_SESSION['user_id'];

        $query = "INSERT INTO `comments` (`comment_text`, `user_id`) VALUES ($comment, $user);";
        $result = mysqli_query($db, $query);

        if($result) {
            echo true;
            exit();
        }
    }
    echo false;
    exit();
?>

How to search if dictionary value contains certain string with Python

import json 'mtach' in json.dumps(myDict) is true if found

Display current time in 12 hour format with AM/PM

Use this SimpleDateFormat formatDate = new SimpleDateFormat("hh:mm a");

enter image description here

Java docs for SimpleDateFormat

How to manage Angular2 "expression has changed after it was checked" exception when a component property depends on current datetime

Use a default form value to avoid the error.

Instead of using the accepted answer of applying detectChanges() in ngAfterViewInit() (which also solved the error in my case), I decided instead to save a default value for a dynamically required form field, so that when the form is later updated, it's validity is not changed if the user decides to change an option on the form that would trigger the new required fields (and cause the submit button to be disabled).

This saved a tiny bit of code in my component, and in my case the error was avoided altogether.

Character Limit on Instagram Usernames

Limit - 30 symbols. Username must contains only letters, numbers, periods and underscores.

jQuery - How to dynamically add a validation rule

The documentation says:

Adds the specified rules and returns all rules for the first matched element. Requires that the parent form is validated, that is,

> $("form").validate() is called first.

Did you do that? The error message kind of indicates that you didn't.

Reverse HashMap keys and values in Java

To answer your question on how you can do it, you could get the entrySet from your map and then just put into the new map by using getValue as key and getKey as value.

But remember that keys in a Map are unique, which means if you have one value with two different key in your original map, only the second key (in iteration order) will be kep as value in the new map.

How to set a selected option of a dropdown list control using angular JS

It can be usefull. Bindings dose not always work.

<select id="product" class="form-control" name="product" required
        ng-model="issue.productId"
        ng-change="getProductVersions()"
        ng-options="p.id as p.shortName for p in products">
</select>

For example. You fill options list source model from rest-service. Selected value was known befor filling list and was set. After executing rest-request with $http list option be done. But selected option is not set. By unknown reasons AngularJS in shadow $digest executing not bind selected as it shuold be. I gotta use JQuery to set selected. It`s important! Angular in shadow add prefix to value of attr "value" for generated by ng-repeat optinos. For int it is "number:".

$scope.issue.productId = productId;
function activate() {
   $http.get('/product/list')
     .then(function (response) {
       $scope.products = response.data;

       if (productId) {
           console.log("" + $("#product option").length);//for clarity                       
           $timeout(function () {
               console.log("" + $("#product option").length);//for clarity
               $('#product').val('number:'+productId);
               //$scope.issue.productId = productId;//not work at all
           }, 200);
       }
   });
}

How to override toString() properly in Java?

You can't call a constructor as if it was a normal method, you can only call it with new to create a new object:

Kid newKid = new Kid(this.name, this.height, this.bDay);

But constructing a new object from your toString() method is not what you want to be doing.

CSS media query to target iPad and iPad only?

Finally found a solution from : Detect different device platforms using CSS

<link rel="stylesheet" media="all and (device-width: 768px) and (device-height: 1024px) and (orientation:portrait)" href="ipad-portrait.css" />
<link rel="stylesheet" media="all and (device-width: 768px) and (device-height: 1024px) and (orientation:landscape)" href="ipad-landscape.css" />

To reduce HTTP call, this can also be used inside you existing common CSS file:

@media all and (device-width: 768px) and (device-height: 1024px) and (orientation:portrait) {
  .ipad-portrait { color: red; } /* your css rules for ipad portrait */
}
@media all and (device-width: 1024px) and (device-height: 768px) and (orientation:landscape) {
  .ipad-landscape { color: blue; } /* your css rules for ipad landscape */
}

Hope this helps.

Other references:

Android: java.lang.SecurityException: Permission Denial: start Intent

I solved this exception by changing the target sdk version from 19 onwards kitkat version AndroidManifest.xml.

<uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="19" />

How to download and save an image in Android

this code perfectly run in my project

downloadImagesToSdCard(imagepath,imagepath);

private void downloadImagesToSdCard(String downloadUrl,String imageName)
        {
            try
            {
                URL url = new URL("www.xxx.com"+downloadUrl); 
                /* making a directory in sdcard */
            //  String sdCard=Environment.getExternalStorageDirectory().toString();
                ContextWrapper cw = new ContextWrapper(getActivity());
                 // path to /data/data/yourapp/app_data/imageDir
                File directory = cw.getDir("files", Context.MODE_PRIVATE);

                File myDir = new File(directory,"folder");

                /*  if specified not exist create new */
                if(!myDir.exists())
                {
                    myDir.mkdir();
                    Log.v("", "inside mkdir");
                }

                /* checks the file and if it already exist delete */
                String fname = imageName;
                File file = new File (myDir, fname);
                Log.d("file===========path", ""+file);
                if (file.exists ()) 
                    file.delete (); 

                /* Open a connection */
                URLConnection ucon = url.openConnection();
                InputStream inputStream = null;
                HttpURLConnection httpConn = (HttpURLConnection)ucon;
                httpConn.setRequestMethod("GET");
                httpConn.connect();
                inputStream = httpConn.getInputStream();
                /*if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) 
                {
                    inputStream = httpConn.getInputStream();
                }*/

                FileOutputStream fos = new FileOutputStream(file);  
                int totalSize = httpConn.getContentLength();
                int downloadedSize = 0;   
                byte[] buffer = new byte[1024];
                int bufferLength = 0;
                while ( (bufferLength = inputStream.read(buffer)) >0 ) 
                {                 
                    fos.write(buffer, 0, bufferLength);                  
                    downloadedSize += bufferLength;                 
                    Log.i("Progress:","downloadedSize:"+downloadedSize+"totalSize:"+ totalSize) ;
                }   

                fos.close();
                Log.d("test", "Image Saved in sdcard..");  
                viewimage();
            }
            catch(IOException io)
            {                  
                io.printStackTrace();
            }
            catch(Exception e)
            {                     
                e.printStackTrace();
            }


        } 

        public void viewimage()
        {
              String path = serialnumber+".png";
               ContextWrapper cw = new ContextWrapper(getActivity());

                //path to /data/data/yourapp/app_data/dirName
                File directory = cw.getDir("files", Context.MODE_PRIVATE);

                File mypath=new File(directory,"folder/"+path);

                Bitmap b;
                try {
                    b = BitmapFactory.decodeStream(new FileInputStream(mypath));
                //  b.compress(format, quality, stream)
                    profile_image.setImageBitmap(Bitmap.createScaledBitmap(b, 120, 120, false));
                } catch (FileNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
        }

Multiple line code example in Javadoc comment

Enclose your multiline code with <pre></pre> tags.

CMD: Export all the screen content to a text file

Just see this page

in cmd type:

Command | clip

Then open a *.Txt file and Paste. That's it. Done.

Trim leading and trailing spaces from a string in awk

just use a regex as a separator:

', *' - for leading spaces

' *,' - for trailing spaces

for both leading and trailing:

awk -F' *,? *' '{print $1","$2}' input.txt

Selecting a row of pandas series/dataframe by integer index

You can take a look at the source code .

DataFrame has a private function _slice() to slice the DataFrame, and it allows the parameter axis to determine which axis to slice. The __getitem__() for DataFrame doesn't set the axis while invoking _slice(). So the _slice() slice it by default axis 0.

You can take a simple experiment, that might help you:

print df._slice(slice(0, 2))
print df._slice(slice(0, 2), 0)
print df._slice(slice(0, 2), 1)

How to write multiple conditions in Makefile.am with "else if"

ptomato's code can also be written in a cleaner manner like:

ifeq ($(TARGET_CPU),x86)
  TARGET_CPU_IS_X86 := 1
else ifeq ($(TARGET_CPU),x86_64)
  TARGET_CPU_IS_X86 := 1
else
  TARGET_CPU_IS_X86 := 0
endif

This doesn't answer OP's question but as it's the top result on google, I'm adding it here in case it's useful to anyone else.

How to save user input into a variable in html and js

It doesn't work because name is a reserved word in JavaScript. Change the function name to something else.

See http://www.quackit.com/javascript/javascript_reserved_words.cfm

<form id="form" onsubmit="return false;">
    <input style="position:absolute; top:80%; left:5%; width:40%;" type="text" id="userInput" />
    <input style="position:absolute; top:50%; left:5%; width:40%;" type="submit" onclick="othername();" />
</form>

function othername() {
    var input = document.getElementById("userInput").value;
    alert(input);
}

Proper use of 'yield return'

As a conceptual example for understanding when you ought to use yield, let's say the method ConsumeLoop() processes the items returned/yielded by ProduceList():

void ConsumeLoop() {
    foreach (Consumable item in ProduceList())        // might have to wait here
        item.Consume();
}

IEnumerable<Consumable> ProduceList() {
    while (KeepProducing())
        yield return ProduceExpensiveConsumable();    // expensive
}

Without yield, the call to ProduceList() might take a long time because you have to complete the list before returning:

//pseudo-assembly
Produce consumable[0]                   // expensive operation, e.g. disk I/O
Produce consumable[1]                   // waiting...
Produce consumable[2]                   // waiting...
Produce consumable[3]                   // completed the consumable list
Consume consumable[0]                   // start consuming
Consume consumable[1]
Consume consumable[2]
Consume consumable[3]

Using yield, it becomes rearranged, sort of interleaved:

//pseudo-assembly
Produce consumable[0]
Consume consumable[0]                   // immediately yield & Consume
Produce consumable[1]                   // ConsumeLoop iterates, requesting next item
Consume consumable[1]                   // consume next
Produce consumable[2]
Consume consumable[2]                   // consume next
Produce consumable[3]
Consume consumable[3]                   // consume next

And lastly, as many before have already suggested, you should use Version 2 because you already have the completed list anyway.

Java: convert seconds to minutes, hours and days

my quick answer with basic java arithmetic calculation is this:

First consider the following values:

1 Minute = 60 Seconds
1 Hour = 3600 Seconds ( 60 * 60 )
1 Day = 86400 Second ( 24 * 3600 )
  1. First divide the input by 86400, if you you can get a number greater than 0 , this is the number of days. 2.Again divide the remained number you get from the first calculation by 3600, this will give you the number of hours
  2. Then divide the remainder of your second calculation by 60 which is the number of Minutes
  3. Finally the remained number from your third calculation is the number of seconds

the code snippet is as follows:

int input=500000;
int numberOfDays;
int numberOfHours;
int numberOfMinutes;
int numberOfSeconds;

numberOfDays = input / 86400;
numberOfHours = (input % 86400 ) / 3600 ;
numberOfMinutes = ((input % 86400 ) % 3600 ) / 60 
numberOfSeconds = ((input % 86400 ) % 3600 ) % 60  ;

I hope to be helpful to you.

Git submodule update

Git 1.8.2 features a new option ,--remote, that will enable exactly this behavior. Running

git submodule update --rebase --remote

will fetch the latest changes from upstream in each submodule, rebase them, and check out the latest revision of the submodule. As the documentation puts it:

--remote

This option is only valid for the update command. Instead of using the superproject’s recorded SHA-1 to update the submodule, use the status of the submodule’s remote-tracking branch.

This is equivalent to running git pull in each submodule, which is generally exactly what you want.

(This was copied from this answer.)

Best approach to converting Boolean object to string in java

If you are sure that your value is not null you can use third option which is

String str3 = b.toString();

and its code looks like

public String toString() {
    return value ? "true" : "false";
}

If you want to be null-safe use String.valueOf(b) which code looks like

public static String valueOf(Object obj) {
    return (obj == null) ? "null" : obj.toString();
}

so as you see it will first test for null and later invoke toString() method on your object.


Calling Boolean.toString(b) will invoke

public static String toString(boolean b) {
    return b ? "true" : "false";
}

which is little slower than b.toString() since JVM needs to first unbox Boolean to boolean which will be passed as argument to Boolean.toString(...), while b.toString() reuses private boolean value field in Boolean object which holds its state.

How to Disable landscape mode in Android?

It worked for me, Try to add this code in AndroidManifest file

<application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:screenOrientation="portrait"
        android:theme="@style/AppTheme">
        ....
        ....
        </application>

How do I change Bootstrap 3's glyphicons to white?

You can just create your own .white class and add it to the glyphicon element.

.white, .white a {
  color: #fff;
}
<i class="glyphicon glyphicon-home white"></i>

numpy.where() detailed, step-by-step explanation / examples

Here is a little more fun. I've found that very often NumPy does exactly what I wish it would do - sometimes it's faster for me to just try things than it is to read the docs. Actually a mixture of both is best.

I think your answer is fine (and it's OK to accept it if you like). This is just "extra".

import numpy as np

a = np.arange(4,10).reshape(2,3)

wh = np.where(a>7)
gt = a>7
x  = np.where(gt)

print "wh: ", wh
print "gt: ", gt
print "x:  ", x

gives:

wh:  (array([1, 1]), array([1, 2]))
gt:  [[False False False]
      [False  True  True]]
x:   (array([1, 1]), array([1, 2]))

... but:

print "a[wh]: ", a[wh]
print "a[gt]  ", a[gt]
print "a[x]:  ", a[x]

gives:

a[wh]:  [8 9]
a[gt]   [8 9]
a[x]:   [8 9]

Swift how to sort array of custom objects by property value

Swift 4.0, 4.1 & 4.2 First, I created mutable array of type imageFile() as shown below

var arr = [imageFile]()

Create mutable object image of type imageFile() and assign value to properties as shown below

   var image = imageFile()
   image.fileId = 14
   image.fileName = "A"

Now, append this object to array arr

    arr.append(image)

Now, assign the different properties to same mutable object i.e image

   image = imageFile()
   image.fileId = 13
   image.fileName = "B"

Now, again append image object to array arr

    arr.append(image)

Now, we will apply Ascending order on fileId property in array arr objects. Use < symbol for Ascending order

 arr = arr.sorted(by: {$0.fileId < $1.fileId}) // arr has all objects in Ascending order
 print("sorted array is",arr[0].fileId)// sorted array is 13
 print("sorted array is",arr[1].fileId)//sorted array is 14

Now, we will apply Descending order on on fileId property in array arr objects. Use > symbol for Descending order

 arr = arr.sorted(by: {$0.fileId > $1.fileId}) // arr has all objects in Descending order
 print("Unsorted array is",arr[0].fileId)// Unsorted array is 14
 print("Unsorted array is",arr[1].fileId)// Unsorted array is 13

In Swift 4.1. & 4.2 For sorted order use

let sortedArr = arr.sorted { (id1, id2) -> Bool in
  return id1.fileId < id2.fileId // Use > for Descending order
}

How to check if a std::string is set or not?

The default constructor for std::string always returns an object that is set to a null string.

reading external sql script in python

Your code already contains a beautiful way to execute all statements from a specified sql file

# Open and read the file as a single buffer
fd = open('ZooDatabase.sql', 'r')
sqlFile = fd.read()
fd.close()

# all SQL commands (split on ';')
sqlCommands = sqlFile.split(';')

# Execute every command from the input file
for command in sqlCommands:
    # This will skip and report errors
    # For example, if the tables do not yet exist, this will skip over
    # the DROP TABLE commands
    try:
        c.execute(command)
    except OperationalError, msg:
        print "Command skipped: ", msg

Wrap this in a function and you can reuse it.

def executeScriptsFromFile(filename):
    # Open and read the file as a single buffer
    fd = open(filename, 'r')
    sqlFile = fd.read()
    fd.close()

    # all SQL commands (split on ';')
    sqlCommands = sqlFile.split(';')

    # Execute every command from the input file
    for command in sqlCommands:
        # This will skip and report errors
        # For example, if the tables do not yet exist, this will skip over
        # the DROP TABLE commands
        try:
            c.execute(command)
        except OperationalError, msg:
            print "Command skipped: ", msg

To use it

executeScriptsFromFile('zookeeper.sql')

You said you were confused by

result = c.execute("SELECT * FROM %s;" % table);

In Python, you can add stuff to a string by using something called string formatting.

You have a string "Some string with %s" with %s, that's a placeholder for something else. To replace the placeholder, you add % ("what you want to replace it with") after your string

ex:

a = "Hi, my name is %s and I have a %s hat" % ("Azeirah", "cool")
print(a)
>>> Hi, my name is Azeirah and I have a Cool hat

Bit of a childish example, but it should be clear.

Now, what

result = c.execute("SELECT * FROM %s;" % table);

means, is it replaces %s with the value of the table variable.

(created in)

for table in ['ZooKeeper', 'Animal', 'Handles']:


# for loop example

for fruit in ["apple", "pear", "orange"]:
    print fruit
>>> apple
>>> pear
>>> orange

If you have any additional questions, poke me.

java.lang.OutOfMemoryError: bitmap size exceeds VM budget - Android

This explanation might help: http://code.google.com/p/android/issues/detail?id=8488#c80

"Fast Tips:

1) NEVER call System.gc() yourself. This has been propagated as a fix here, and it doesn't work. Do not do it. If you noticed in my explanation, before getting an OutOfMemoryError, the JVM already runs a garbage collection so there is no reason to do one again (its slowing your program down). Doing one at the end of your activity is just covering up the problem. It may causes the bitmap to be put on the finalizer queue faster, but there is no reason you couldn't have simply called recycle on each bitmap instead.

2) Always call recycle() on bitmaps you don't need anymore. At the very least, in the onDestroy of your activity go through and recycle all the bitmaps you were using. Also, if you want the bitmap instances to be collected from the dalvik heap faster, it doesn't hurt to clear any references to the bitmap.

3) Calling recycle() and then System.gc() still might not remove the bitmap from the Dalvik heap. DO NOT BE CONCERNED about this. recycle() did its job and freed the native memory, it will just take some time to go through the steps I outlined earlier to actually remove the bitmap from the Dalvik heap. This is NOT a big deal because the large chunk of native memory is already free!

4) Always assume there is a bug in the framework last. Dalvik is doing exactly what its supposed to do. It may not be what you expect or what you want, but its how it works. "

Reading integers from binary file in Python

As you are reading the binary file, you need to unpack it into a integer, so use struct module for that

import struct
fin = open("hi.bmp", "rb")
firm = fin.read(2)  
file_size, = struct.unpack("i",fin.read(4))

Division in Python 2.7. and 3.3

In Python 3, / is float division

In Python 2, / is integer division (assuming int inputs)

In both 2 and 3, // is integer division

(To get float division in Python 2 requires either of the operands be a float, either as 20. or float(20))

Automatically open Chrome developer tools when new tab/new window is opened

UPDATE 2:

See this answer . - 2019-11-05

You can also now have it auto-open Developer Tools in Pop-ups if they were open where you opened them from. For example, if you do not have Dev Tools open and you get a popup, it won't open with Dev Tools. But if you Have Dev Tools Open and then you click something, the popup will have Dev-Tools Automatically opened.

UPDATE:

Time has changed, you can now use --auto-open-devtools-for-tabs as in this answer – Wouter Huysentruit May 18 at 11:08

OP:

I played around with the startup string for Chrome on execute, but couldn't get it to persist to new tabs.
I also thought about a defined PATH method that you could invoke from prompt. This is possible with the SendKeys command, but again, only on a new instance. And DevTools doesn't persist to new tabs.

Browsing the Google Product Forums, there doesn't seem to be a built-in way to do this in Chrome. You'll have to use a keystroke solution or F12 as mentioned above.

I recommended it as a feature. I know I'm not the first either.

How do I set the classpath in NetBeans?

Maven

The Answer by Bhesh Gurung is correct… unless your NetBeans project is Maven based.

Dependency

Under Maven, you add a "dependency". A dependency is a description of a library (its name & version number) you want to use from your code.

Or a dependency could be a description of a library which another library needs ("depends on"). Maven automatically handles this chain, libraries that need other libraries that then need other libraries and so on. For the mathematical-minded, perhaps the phrase "Maven resolves the transitive dependencies" makes sense.

Repository

Maven gets this related-ness information, and the libraries themselves from a Maven repository. A repository is basically an online database and collection of download files (the dependency library).

Easy to Use

Adding a dependency to a Maven-based project is really quite easy. That is the whole point to Maven, to make managing dependent libraries easy and to make building them into your project easy. To get started with adding a dependency, see this Question, Adding dependencies in Maven Netbeans and my Answer with screenshot.

enter image description here

Cannot access wamp server on local network

Turn off your firewall for port 80 from any address. Turn off 443 if you need https (SSL) access. Open the configuration file (http.conf) and find the lines that say:

Allow from 127.0.0.1

Change them to read

Allow from all

Restart the wampserver. It will now work. Enjoy!!

Center an element with "absolute" position and undefined width in CSS?

A simple approach that worked for me to horizontally center a block of unknown width:

<div id="wrapper">
  <div id="block"></div>
</div>

#wrapper {
    position: absolute;
    width: 100%;
    text-align: center;
}

#block {
    display: inline-block;
}

A text-align property may be added to the #block ruleset to align its content independently of the alignment of the block.

This worked on recent versions of Firefox, Chrome, Internet Explorer, Edge and Safari.

What is char ** in C?

Technically, the char* is not an array, but a pointer to a char.

Similarly, char** is a pointer to a char*. Making it a pointer to a pointer to a char.

C and C++ both define arrays behind-the-scenes as pointer types, so yes, this structure, in all likelihood, is array of arrays of chars, or an array of strings.

How to get a dependency tree for an artifact?

If you'd like to get a graphical, searchable representation of the dependency tree (including all modules from your project, transitive dependencies and eviction information), check out UpdateImpact: https://app.updateimpact.com (free service).

Disclaimer: I'm one of the developers of the site

angular js unknown provider

My case was dodgy typing

myApp.factory('Notify',funtion(){

function has a 'c' !

Best way to save a trained model in PyTorch?

The pickle Python library implements binary protocols for serializing and de-serializing a Python object.

When you import torch (or when you use PyTorch) it will import pickle for you and you don't need to call pickle.dump() and pickle.load() directly, which are the methods to save and to load the object.

In fact, torch.save() and torch.load() will wrap pickle.dump() and pickle.load() for you.

A state_dict the other answer mentioned deserves just few more notes.

What state_dict do we have inside PyTorch? There are actually two state_dicts.

The PyTorch model is torch.nn.Module has model.parameters() call to get learnable parameters (w and b). These learnable parameters, once randomly set, will update over time as we learn. Learnable parameters are the first state_dict.

The second state_dict is the optimizer state dict. You recall that the optimizer is used to improve our learnable parameters. But the optimizer state_dict is fixed. Nothing to learn in there.

Because state_dict objects are Python dictionaries, they can be easily saved, updated, altered, and restored, adding a great deal of modularity to PyTorch models and optimizers.

Let's create a super simple model to explain this:

import torch
import torch.optim as optim

model = torch.nn.Linear(5, 2)

# Initialize optimizer
optimizer = optim.SGD(model.parameters(), lr=0.001, momentum=0.9)

print("Model's state_dict:")
for param_tensor in model.state_dict():
    print(param_tensor, "\t", model.state_dict()[param_tensor].size())

print("Model weight:")    
print(model.weight)

print("Model bias:")    
print(model.bias)

print("---")
print("Optimizer's state_dict:")
for var_name in optimizer.state_dict():
    print(var_name, "\t", optimizer.state_dict()[var_name])

This code will output the following:

Model's state_dict:
weight   torch.Size([2, 5])
bias     torch.Size([2])
Model weight:
Parameter containing:
tensor([[ 0.1328,  0.1360,  0.1553, -0.1838, -0.0316],
        [ 0.0479,  0.1760,  0.1712,  0.2244,  0.1408]], requires_grad=True)
Model bias:
Parameter containing:
tensor([ 0.4112, -0.0733], requires_grad=True)
---
Optimizer's state_dict:
state    {}
param_groups     [{'lr': 0.001, 'momentum': 0.9, 'dampening': 0, 'weight_decay': 0, 'nesterov': False, 'params': [140695321443856, 140695321443928]}]

Note this is a minimal model. You may try to add stack of sequential

model = torch.nn.Sequential(
          torch.nn.Linear(D_in, H),
          torch.nn.Conv2d(A, B, C)
          torch.nn.Linear(H, D_out),
        )

Note that only layers with learnable parameters (convolutional layers, linear layers, etc.) and registered buffers (batchnorm layers) have entries in the model's state_dict.

Non learnable things, belong to the optimizer object state_dict, which contains information about the optimizer's state, as well as the hyperparameters used.

The rest of the story is the same; in the inference phase (this is a phase when we use the model after training) for predicting; we do predict based on the parameters we learned. So for the inference, we just need to save the parameters model.state_dict().

torch.save(model.state_dict(), filepath)

And to use later model.load_state_dict(torch.load(filepath)) model.eval()

Note: Don't forget the last line model.eval() this is crucial after loading the model.

Also don't try to save torch.save(model.parameters(), filepath). The model.parameters() is just the generator object.

On the other side, torch.save(model, filepath) saves the model object itself, but keep in mind the model doesn't have the optimizer's state_dict. Check the other excellent answer by @Jadiel de Armas to save the optimizer's state dict.

Difference between \b and \B in regex

Let take a string like :

XIX IXI XX X I II IIXX XXII I-I X-X -X X- X-I I-X -X- -I-X -X-I I-X- X-I- X_X _X-

Note: Underscore ( _ ) is not considered a special character in this case.

  1. /\bX\b/g Should begin and end with a special character or white Space

XIX IXI XX X I II IIXX XXII I-I X-X -X X- X-I I-X -X- -I-X -X-I I-X- X-I- X_X _X-


  1. /\bX/g Should begin with a special character or white Space

XIX IXI XX X I II IIXX XXII I-I X-X -X X- X-I I-X -X- -I-X -X-I I-X- X-I- X_X _X-


  1. /X\b/g Should end with a special character or white Space

XIX IXI XX X I II IIXX XXII I-I X-X -X X- X-I I-X -X- -I-X -X-I I-X- X-I- X_X _X-


  1. /\BX\B/g
    Should not begin and not end with a special character or white Space

XIX IXI XX X I II IIXX XXII I-I X-X -X X- X-I I-X -X- -I-X -X-I I-X- X-I- X_X _X-


  1. /\BX/g Should not begin with a special character or white Space

XIX IXI XX X I II IIXX XXII I-I X-X -X X- X-I I-X -X- -I-X -X-I I-X- X-I- X_X _X-


  1. /X\B/g Should not end with a special character or white Space

XIX IXI XX X I II IIXX XXII I-I X-X -X X- X-I I-X -X- -I-X -X-I I-X- X-I- X_X _X-


  1. /\bX\B/g Should begin and not end with a special character or white Space

XIX IXI XX X I II IIXX XXII I-I X-X -X X- X-I I-X -X- -I-X -X-I I-X- X-I- X_X _X-


  1. /\BX\b/g Should not begin and should end with a special character or white Space

XIX IXI XX X I II IIXX XXII I-I X-X -X X- X-I I-X -X- -I-X -X-I I-X- X-I- X_X _X-

Go to Matching Brace in Visual Studio?

On a Hungarian keyboard it is Ctrl + ú.

Finding row index containing maximum value using R

See ?which.max

> which.max( matrix[,2] )
[1] 2

JQuery: dynamic height() with window resize()

I feel like there should be a no javascript solution, but how is this?

http://jsfiddle.net/NfmX3/2/

$(window).resize(function() {
    $('#content').height($(window).height() - 46);
});

$(window).trigger('resize');

Deleting all records in a database table

More recent answer in the case you want to delete every entries in every tables:

def reset
    Rails.application.eager_load!
    ActiveRecord::Base.descendants.each { |c| c.delete_all unless c == ActiveRecord::SchemaMigration  }
end

More information about the eager_load here.

After calling it, we can access to all of the descendants of ActiveRecord::Base and we can apply a delete_all on all the models.

Note that we make sure not to clear the SchemaMigration table.

How to combine GROUP BY, ORDER BY and HAVING

Steps for Using Group by,Having By and Order by...

Select Attitude ,count(*) from Person
group by person
HAving PersonAttitude='cool and friendly'
Order by PersonName.

Setting equal heights for div's with jQuery

You can reach each separate container using .parent() API.

Like,

var highestBox = 0;
        $('.container .column').each(function(){  
                if($(this).parent().height() > highestBox){  
                highestBox = $(this).height();  
        }
    }); 

Set color of text in a Textbox/Label to Red and make it bold in asp.net C#

string minusvalue = TextBox1.Text.ToString();

if (Convert.ToDouble(minusvalue) < 0)
{ 
    // set color of text in TextBox1 to red color and bold.
    TextBox1.ForeColor = Color.Red;
}

keycode 13 is for which key

key 13 keycode is for ENTER key.

How to read from standard input in the console?

Try this code:-

var input string
func main() {
      fmt.Print("Enter Your Name=")
      fmt.Scanf("%s",&input)
      fmt.Println("Hello "+input)
      }

ASP.NET 4.5 has not been registered on the Web server

run visual studio in admin rights and execute following "commandaspnet_regiis -i"

How do you update Xcode on OSX to the latest version?

Another best way to update and upgrade OSX development tools using command line is as follows:

Open terminal on OSX and type below commands. Try 'sudo' as prefix if you don't have admin privileges.

brew update

and for upgrading outdated tools and libraries use below command

brew upgrade

These will update all packages like node, rethinkDB and much more.

Also, softwareupdate --install --all this command also work best.

Important: Remove all outdated packages and free some space using the simple command.

brew cleanup

Spring Boot yaml configuration for a list of strings

@Value("#{'${your.elements}'.split(',')}")  
private Set<String> stringSet;

yml file:

your:
 elements: element1, element2, element3

There is lot more you can play with spring spEL.

Skip first couple of lines while reading lines in Python file

Here is a method to get lines between two line numbers in a file:

import sys

def file_line(name,start=1,end=sys.maxint):
    lc=0
    with open(s) as f:
        for line in f:
            lc+=1
            if lc>=start and lc<=end:
                yield line


s='/usr/share/dict/words'
l1=list(file_line(s,235880))
l2=list(file_line(s,1,10))
print l1
print l2

Output:

['Zyrian\n', 'Zyryan\n', 'zythem\n', 'Zythia\n', 'zythum\n', 'Zyzomys\n', 'Zyzzogeton\n']
['A\n', 'a\n', 'aa\n', 'aal\n', 'aalii\n', 'aam\n', 'Aani\n', 'aardvark\n', 'aardwolf\n', 'Aaron\n']

Just call it with one parameter to get from line n -> EOF

How to return a value from __init__ in Python?

__init__ doesn't return anything and should always return None.

Scripting Language vs Programming Language

All scripting languages are programming languages.

Languages are not classed as script or not - it entirely depends on the execution environment.

If the environment is one that is interpreted, this is commonly referred to as a scripting environment.

How to convert a DataFrame back to normal RDD in pyspark?

Use the method .rdd like this:

rdd = df.rdd

How can I clear the content of a file?

Use FileMode.Truncate everytime you create the file. Also place the File.Create inside a try catch.

How to set text color in submit button?

.btn{
    font-size: 20px;
    color:black;
}

What is the meaning of the CascadeType.ALL for a @ManyToOne JPA association

From the EJB3.0 Specification:

Use of the cascade annotation element may be used to propagate the effect of an operation to associated entities. The cascade functionality is most typically used in parent-child relationships.

If X is a managed entity, the remove operation causes it to become removed. The remove operation is cascaded to entities referenced by X, if the relationships from X to these other entities is annotated with the cascade=REMOVE or cascade=ALL annotation element value.

So in a nutshell, entity relationships defined with CascadeType.All will ensure that all persistence events such as persist, refresh, merge and remove that occur on the parent, will be passed to the child. Defining other CascadeType options provides the developer with a more granular level of control over how the entity association handles persistence.

For example if I had an object Book that contained a List of pages and I add a page object within this list. If the @OneToMany annotation defining the association between Book and Page is marked as CascadeType.All, persisting the Book would result in the Page also being persisted to the database.

Setting Camera Parameters in OpenCV/Python

I had the same problem with openCV on Raspberry Pi... don't know if this can solve your problem, but what worked for me was

import time
import cv2


cap = cv2.VideoCapture(0)

cap.set(3,1280)

cap.set(4,1024)

time.sleep(2)

cap.set(15, -8.0)

the time you have to use can be different

Yii2 data provider default sorting

Or

       $dataProvider->setSort([
        'defaultOrder' => ['topic_order'=>SORT_DESC],
        'attributes' => [...

Java: Calling a super method which calls an overridden method

class SuperClass
{
    public void method1()
    {
        System.out.println("superclass method1");
        SuperClass se=new SuperClass();
        se.method2();
    }

    public void method2()
    {
        System.out.println("superclass method2");
    }
}


class SubClass extends SuperClass
{
    @Override
    public void method1()
    {
        System.out.println("subclass method1");
        super.method1();
    }

    @Override
    public void method2()
    {
        System.out.println("subclass method2");
    }
}

calling

SubClass mSubClass = new SubClass();
mSubClass.method1();

outputs

subclass method1
superclass method1
superclass method2

Password Strength Meter

Here's a collection of scripts: http://webtecker.com/2008/03/26/collection-of-password-strength-scripts/

I think both of them rate the password and don't use jQuery... but I don't know if they have native support for disabling the form?

Spring Boot Rest Controller how to return different HTTP status codes?

Try this code:

@RequestMapping(value = "/validate", method = RequestMethod.GET, produces = "application/json")
public ResponseEntity<ErrorBean> validateUser(@QueryParam("jsonInput") final String jsonInput) {
    int numberHTTPDesired = 400;
    ErrorBean responseBean = new ErrorBean();
    responseBean.setError("ERROR");
    responseBean.setMensaje("Error in validation!");

    return new ResponseEntity<ErrorBean>(responseBean, HttpStatus.valueOf(numberHTTPDesired));
}

Picasso v/s Imageloader v/s Fresco vs Glide

Mind you that this is a highly opinion based question, so I stopped making fjords and made a quick table

enter image description here

Now library comparison is hard because on many parameters, all the four pretty much do the same thing, except possibly for Fresco because there is a whole bunch of new memory level optimizations in it.So let me know if certain parameters you'd like to see a comparison for based on my experience.

Having used Fresco the least, the answer might evolve as I continue to use and understand it for current exploits. The used personally is having used the library atleast once in a completed app.

*Note - Fresco now supports GIF as well as WebP animations

How can I restart a Java application?

If you realy need to restart your app, you could write a separate app the start it...

This page provides many different examples for different scenarios:

http://www.rgagnon.com/javadetails/java-0014.html

How to read the post request parameters using JavaScript

A little piece of PHP to get the server to populate a JavaScript variable is quick and easy:

var my_javascript_variable = <?php echo json_encode($_POST['my_post'] ?? null) ?>;

Then just access the JavaScript variable in the normal way.

Note there is no guarantee any given data or kind of data will be posted unless you check - all input fields are suggestions, not guarantees.

Regular expression replace in C#

Add the following 2 lines

var regex = new Regex(Regex.Escape(","));
sb_trim = regex.Replace(sb_trim, " ", 1);

If sb_trim= John,Smith,100000,M the above code will return "John Smith,100000,M"

How to compare times in Python?

Inspired by Roger Pate:

import datetime
def todayAt (hr, min=0, sec=0, micros=0):
   now = datetime.datetime.now()
   return now.replace(hour=hr, minute=min, second=sec, microsecond=micros)    

# Usage demo1:
print todayAt (17), todayAt (17, 15)

# Usage demo2:    
timeNow = datetime.datetime.now()
if timeNow < todayAt (13):
   print "Too Early"

How to get year and month from a date - PHP

I will share my code:

In your given example date:

$dateValue = '2012-01-05';

It will go like this:

dateName($dateValue);



   function dateName($date) {

        $result = "";

        $convert_date = strtotime($date);
        $month = date('F',$convert_date);
        $year = date('Y',$convert_date);
        $name_day = date('l',$convert_date);
        $day = date('j',$convert_date);


        $result = $month . " " . $day . ", " . $year . " - " . $name_day;

        return $result;
    }

and will return a value: January 5, 2012 - Thursday

Adjusting HttpWebRequest Connection Timeout in C#

From the documentation of the HttpWebRequest.Timeout property:

A Domain Name System (DNS) query may take up to 15 seconds to return or time out. If your request contains a host name that requires resolution and you set Timeout to a value less than 15 seconds, it may take 15 seconds or more before a WebException is thrown to indicate a timeout on your request.

Is it possible that your DNS query is the cause of the timeout?

What is logits, softmax and softmax_cross_entropy_with_logits?

tf.nn.softmax computes the forward propagation through a softmax layer. You use it during evaluation of the model when you compute the probabilities that the model outputs.

tf.nn.softmax_cross_entropy_with_logits computes the cost for a softmax layer. It is only used during training.

The logits are the unnormalized log probabilities output the model (the values output before the softmax normalization is applied to them).