Programs & Examples On #Ec2 api tools

Command-line scripting tools for interfacing with Amazon's EC2 computing platform.

How do I iterate through children elements of a div using jQuery?

It can be done this way as well:

$('input', '#div').each(function () {
    console.log($(this)); //log every element found to console output
});

Converting Milliseconds to Minutes and Seconds?

You can try proceeding this way:

Pass ms value from

Long ms = watch.getTime();

to

getDisplayValue(ms)

Kotlin implementation:

fun getDisplayValue(ms: Long): String {
        val duration = Duration.ofMillis(ms)
        val minutes = duration.toMinutes()
        val seconds = duration.minusMinutes(minutes).seconds

        return "${minutes}min ${seconds}sec"
}

Java implementation:

public String getDisplayValue(Long ms) {
        Duration duration = Duration.ofMillis(ms);
        Long minutes = duration.toMinutes();
        Long seconds = duration.minusMinutes(minutes).getSeconds();

        return minutes + "min " + seconds "sec"
}

Is there a difference between /\s/g and /\s+/g?

+ means "one or more characters" and without the plus it means "one character." In your case both result in the same output.

How do I copy a range of formula values and paste them to a specific range in another sheet?

You can change

Range("B3:B65536").Copy Destination:=Sheets("DB").Range("B" & lastrow)

to

Range("B3:B65536").Copy 
Sheets("DB").Range("B" & lastrow).PasteSpecial xlPasteValues

BTW, if you have xls file (excel 2003), you would get an error if your lastrow would be greater 3.

Try to use this code instead:

Sub Get_Data()
    Dim lastrowDB As Long, lastrow As Long
    Dim arr1, arr2, i As Integer

    With Sheets("DB")
        lastrowDB = .Cells(.Rows.Count, "A").End(xlUp).Row + 1
    End With

    arr1 = Array("B", "C", "D", "E", "F", "AH", "AI", "AJ", "J", "P", "AF")
    arr2 = Array("B", "A", "C", "P", "D", "E", "G", "F", "H", "I", "J")

    For i = LBound(arr1) To UBound(arr1)
        With Sheets("Sheet1")
             lastrow = Application.Max(3, .Cells(.Rows.Count, arr1(i)).End(xlUp).Row)
             .Range(.Cells(3, arr1(i)), .Cells(lastrow, arr1(i))).Copy
             Sheets("DB").Range(arr2(i) & lastrowDB).PasteSpecial xlPasteValues
        End With
    Next
    Application.CutCopyMode = False
End Sub

Note, above code determines last non empty row on DB sheet in column A (variable lastrowDB). If you need to find lastrow for each destination column in DB sheet, use next modification:

For i = LBound(arr1) To UBound(arr1)
   With Sheets("DB")
       lastrowDB = .Cells(.Rows.Count, arr2(i)).End(xlUp).Row + 1
   End With

   ' NEXT CODE

Next

You could also use next approach instead Copy/PasteSpecial. Replace

.Range(.Cells(3, arr1(i)), .Cells(lastrow, arr1(i))).Copy
Sheets("DB").Range(arr2(i) & lastrowDB).PasteSpecial xlPasteValues

with

Sheets("DB").Range(arr2(i) & lastrowDB).Resize(lastrow - 2).Value = _
      .Range(.Cells(3, arr1(i)), .Cells(lastrow, arr1(i))).Value

Create request with POST, which response codes 200 or 201 and content

The idea is that the response body gives you a page that links you to the thing:

201 Created

The 201 (Created) status code indicates that the request has been fulfilled and has resulted in one or more new resources being created. The primary resource created by the request is identified by either a Location header field in the response or, if no Location field is received, by the effective request URI.

This means that you would include a Location in the response header that gives the URL of where you can find the newly created thing:

HTTP/1.1 201 Created
Date: Sat, 02 Apr 2016 12:22:40 GMT
Location: http://stackoverflow.com/a/36373586/12597

Response body

They then go on to mention what you should include in the response body:

The 201 response payload typically describes and links to the resource(s) created.

For the human using the browser, you give them something they can look at, and click, to get to their newly created resource:

HTTP/1.1 201 Created
Date: Sat, 02 Apr 2016 12:22:40 GMT
Location: http://stackoverflow.com/a/36373586/12597
Content-Type: text/html

Your answer has been saved! 
Click <A href="/a/36373586/12597">here</A> to view it.

If the page will only be used by a robot, the it makes sense to have the response be computer readable:

HTTP/1.1 201 Created
Date: Sat, 02 Apr 2016 12:22:40 GMT
Location: http://stackoverflow.com/a/36373586/12597
Content-Type: application/xml

<createdResources>
   <questionID>1860645</questionID>
   <answerID>36373586</answerID>
   <primary>/a/36373586/12597</primary>
   <additional>
      <resource>http://stackoverflow.com/questions/1860645/create-request-with-post-which-response-codes-200-or-201-and-content/36373586#36373586</resource>
      <resource>http://stackoverflow.com/a/1962757/12597</resource>
   </additional>
</createdResource>

Or, if you prefer:

HTTP/1.1 201 Created
Date: Sat, 02 Apr 2016 12:22:40 GMT
Location: http://stackoverflow.com/a/36373586/12597
Content-Type: application/json

{ 
   "questionID": 1860645, 
   "answerID": 36373586,
   "primary": "/a/36373586/12597",
   "additional": [
      "http://stackoverflow.com/questions/1860645/create-request-with-post-which-response-codes-200-or-201-and-content/36373586#36373586",
      "http://stackoverflow.com/a/36373586/12597"
   ]
}

The response is entirely up to you; it's arbitrarily what you'd like.

Cache friendly

Finally there's the optimization that I can pre-cache the created resource (because I already have the content; I just uploaded it). The server can return a date or ETag which I can store with the content I just uploaded:

See Section 7.2 for a discussion of the meaning and purpose of validator header fields, such as ETag and Last-Modified, in a 201 response.

HTTP/1.1 201 Created
Date: Sat, 02 Apr 2016 12:22:40 GMT
Location: http://stackoverflow.com/a/23704283/12597
Content-Type: text/html
ETag: JF2CA53BOMQGU5LTOQQGC3RAMV4GC3LQNRSS4
Last-Modified: Sat, 02 Apr 2016 12:22:39 GMT 

Your answer has been saved! 
Click <A href="/a/36373586/12597">here</A> to view it.

And ETag s are purely arbitrary values. Having them be different when a resource changes (and caches need to be updated) is all that matters. The ETag is usually a hash (e.g. SHA2). But it can be a database rowversion, or an incrementing revision number. Anything that will change when the thing changes.

Pandas Merging 101

This post will go through the following topics:

  • how to correctly generalize to multiple DataFrames (and why merge has shortcomings here)
  • merging on unique keys
  • merging on non-unqiue keys

BACK TO TOP



Generalizing to multiple DataFrames

Oftentimes, the situation arises when multiple DataFrames are to be merged together. Naively, this can be done by chaining merge calls:

df1.merge(df2, ...).merge(df3, ...)

However, this quickly gets out of hand for many DataFrames. Furthermore, it may be necessary to generalise for an unknown number of DataFrames.

Here I introduce pd.concat for multi-way joins on unique keys, and DataFrame.join for multi-way joins on non-unique keys. First, the setup.

# Setup.
np.random.seed(0)
A = pd.DataFrame({'key': ['A', 'B', 'C', 'D'], 'valueA': np.random.randn(4)})    
B = pd.DataFrame({'key': ['B', 'D', 'E', 'F'], 'valueB': np.random.randn(4)})
C = pd.DataFrame({'key': ['D', 'E', 'J', 'C'], 'valueC': np.ones(4)})
dfs = [A, B, C] 

# Note, the "key" column values are unique, so the index is unique.
A2 = A.set_index('key')
B2 = B.set_index('key')
C2 = C.set_index('key')

dfs2 = [A2, B2, C2]

Multiway merge on unique keys

If your keys (here, the key could either be a column or an index) are unique, then you can use pd.concat. Note that pd.concat joins DataFrames on the index.

# merge on `key` column, you'll need to set the index before concatenating
pd.concat([
    df.set_index('key') for df in dfs], axis=1, join='inner'
).reset_index()

  key    valueA    valueB  valueC
0   D  2.240893 -0.977278     1.0

# merge on `key` index
pd.concat(dfs2, axis=1, sort=False, join='inner')

       valueA    valueB  valueC
key                            
D    2.240893 -0.977278     1.0

Omit join='inner' for a FULL OUTER JOIN. Note that you cannot specify LEFT or RIGHT OUTER joins (if you need these, use join, described below).


Multiway merge on keys with duplicates

concat is fast, but has its shortcomings. It cannot handle duplicates.

A3 = pd.DataFrame({'key': ['A', 'B', 'C', 'D', 'D'], 'valueA': np.random.randn(5)})
pd.concat([df.set_index('key') for df in [A3, B, C]], axis=1, join='inner')
ValueError: Shape of passed values is (3, 4), indices imply (3, 2)

In this situation, we can use join since it can handle non-unique keys (note that join joins DataFrames on their index; it calls merge under the hood and does a LEFT OUTER JOIN unless otherwise specified).

# join on `key` column, set as the index first
# For inner join. For left join, omit the "how" argument.
A.set_index('key').join(
    [df.set_index('key') for df in (B, C)], how='inner').reset_index()

  key    valueA    valueB  valueC
0   D  2.240893 -0.977278     1.0

# join on `key` index
A3.set_index('key').join([B2, C2], how='inner')

       valueA    valueB  valueC
key                            
D    1.454274 -0.977278     1.0
D    0.761038 -0.977278     1.0


Continue Reading

Jump to other topics in Pandas Merging 101 to continue learning:

* you are here

How can one use multi threading in PHP applications

You can use exec() to run a command line script (such as command line php), and if you pipe the output to a file then your script won't wait for the command to finish.

I can't quite remember the php CLI syntax, but you'd want something like:

exec("/path/to/php -f '/path/to/file.php' | '/path/to/output.txt'");

I think quite a few shared hosting servers have exec() disabled by default for security reasons, but might be worth a try.

Is there a Visual Basic 6 decompiler?

Yes I think You can get it download and separately its Help files from: vbdecompiler.org Site. and there is a Video on YouTube which explains how to Use it to Get the Code from an exe file and Save it. I hope that I helped.

Override default Spring-Boot application.properties settings in Junit Test

Simple explanation:

If you are like me and you have the same application.properties in src/main/resources and src/test/resources, and you are wondering why the application.properties in your test folder is not overriding the application.properties in your main resources, read on...

If you have application.properties under src/main/resources and the same application.properties under src/test/resources, which application.properties gets picked up, depends on how you are running your tests. The folder structure src/main/resources and src/test/resources, is a Maven architectural convention, so if you run your test like mvnw test or even gradlew test, the application.properties in src/test/resources will get picked up, as test classpath will precede main classpath. But, if you run your test like Run as JUnit Test in Eclipse/STS, the application.properties in src/main/resources will get picked up, as main classpath precedes test classpath.

You can check it out by opening the menu bar Run > Run Configurations > JUnit > *your_run_configuration* > Click on "Show Command Line".

You will see something like this:

XXXbin\javaw.exe -ea -Dfile.encoding=UTF-8 -classpath
XXX\workspace-spring-tool-suite-4-4.5.1.RELEASE\project_name\bin\main;
XXX\workspace-spring-tool-suite-4-4.5.1.RELEASE\project_name\bin\test;

Do you see that classpath xxx\main comes first, and then xxx\test? Right, it's all about classpath :-)

Side-note: Be mindful that properties overridden in the Launch Configuration(In Spring Tool Suite IDE, for example) takes priority over application.properties.

How to show soft-keyboard when edittext is focused

All solutions given above (InputMethodManager interaction in OnFocusChangeListener.onFocusChange listener attached to your EditText works fine if you have single edit in the activity.

In my case I have two edits.

 private EditText tvX, tvY;
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
 tvX.setOnFocusChangeListener(this);
    tvY.setOnFocusChangeListener(this);

@Override
public void onFocusChange(View v, boolean hasFocus) {       
    InputMethodManager imm =  (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    if(tvX.hasFocus() || tvY.hasFocus()) {            
        imm.showSoftInput(v, 0);            
    } else {
        imm.hideSoftInputFromWindow(v.getWindowToken(), 0);         
    }       
};

I have observed that onFocusChange is triggered for tvX with hasFocus=true (keyboard shown) but then for tvY with hasFocus=true (keyboard hidden). In the end, no keyboard was visible.

General solution should have correct statement in if "show keyboard if EditText text has focus"

Convert Python program to C/C++ code?

Yes. Look at Cython. It does just that: Converts Python to C for speedups.

Convert String array to ArrayList

Use this code for that,

import java.util.Arrays;  
import java.util.List;  
import java.util.ArrayList;  

public class StringArrayTest {

   public static void main(String[] args) {  
      String[] words = {"ace", "boom", "crew", "dog", "eon"};  

      List<String> wordList = Arrays.asList(words);  

      for (String e : wordList) {  
         System.out.println(e);  
      }  
   }  
}

Java JTable getting the data of the selected row

Just simple like this:

    tbl.addMouseListener(new MouseListener() {
        @Override
        public void mouseReleased(MouseEvent e) {
        }
        @Override
        public void mousePressed(MouseEvent e) {
            String selectedCellValue = (String) tbl.getValueAt(tbl.getSelectedRow() , tbl.getSelectedColumn());
            System.out.println(selectedCellValue);
        }
        @Override
        public void mouseExited(MouseEvent e) {
        }
        @Override
        public void mouseEntered(MouseEvent e) {
        }
        @Override
        public void mouseClicked(MouseEvent e) {
        }
    });

How to emulate a do-while loop in Python?

do {
  stuff()
} while (condition())

->

while True:
  stuff()
  if not condition():
    break

You can do a function:

def do_while(stuff, condition):
  while condition(stuff()):
    pass

But 1) It's ugly. 2) Condition should be a function with one parameter, supposed to be filled by stuff (it's the only reason not to use the classic while loop.)

What does the symbol \0 mean in a string-literal?

Specifically, I want to mention one situation, by which you may confuse.

What is the difference between "\0" and ""?

The answer is that "\0" represents in array is {0 0} and "" is {0}.

Because "\0" is still a string literal and it will also add "\0" at the end of it. And "" is empty but also add "\0".

Understanding of this will help you understand "\0" deeply.

How to post JSON to PHP with curl

You should escape the quotes like this:

curl -i -X POST -d '{\"screencast\":{\"subject\":\"tools\"}}'  \
  http://localhost:3570/index.php/trainingServer/screencast.json

Failed linking file resources

Add agian your deleted drawable image .jpg/png etc formate. enter image description hereand Then run your project to fine working on android studio 3.6.1

Java - What does "\n" mean?

\n is add a new line.

Please note java has method System.out.println("Write text here");

Notice the difference:

Code:

System.out.println("Text 1");
System.out.println("Text 2");

Output:

Text 1
Text 2

Code:

System.out.print("Text 1");
System.out.print("Text 2");

Output:

Text 1Text 2

How to select all rows which have same value in some column

How about

SELECT *
FROM Employees
WHERE PhoneNumber IN (
    SELECT PhoneNumber
    FROM Employees
    GROUP BY PhoneNumber
    HAVING COUNT(Employee_ID) > 1
    )

SQL Fiddle DEMO

Display Last Saved Date on worksheet

May be this time stamp fit you better Code

Function LastInputTimeStamp() As Date
  LastInputTimeStamp = Now()
End Function

and each time you input data in defined cell (in my example below it is cell C36) you'll get a new constant time stamp. As an example in Excel file may use this

=IF(C36>0,LastInputTimeStamp(),"")

Insert at first position of a list in Python

Use insert:

In [1]: ls = [1,2,3]

In [2]: ls.insert(0, "new")

In [3]: ls
Out[3]: ['new', 1, 2, 3]

How to insert data into SQL Server

I think you lack to pass Connection object to your command object. and it is much better if you will use command and parameters for that.

using (SqlConnection connection = new SqlConnection("ConnectionStringHere"))
{
    using (SqlCommand command = new SqlCommand())
    {
        command.Connection = connection;            // <== lacking
        command.CommandType = CommandType.Text;
        command.CommandText = "INSERT into tbl_staff (staffName, userID, idDepartment) VALUES (@staffName, @userID, @idDepart)";
        command.Parameters.AddWithValue("@staffName", name);
        command.Parameters.AddWithValue("@userID", userId);
        command.Parameters.AddWithValue("@idDepart", idDepart);

        try
        {
            connection.Open();
            int recordsAffected = command.ExecuteNonQuery();
        }
        catch(SqlException)
        {
            // error here
        }
        finally
        {
            connection.Close();
        }
    }
}

Access-Control-Allow-Origin Multiple Origin Domains?

Sounds like the recommended way to do it is to have your server read the Origin header from the client, compare that to the list of domains you would like to allow, and if it matches, echo the value of the Origin header back to the client as the Access-Control-Allow-Origin header in the response.

With .htaccess you can do it like this:

# ----------------------------------------------------------------------
# Allow loading of external fonts
# ----------------------------------------------------------------------
<FilesMatch "\.(ttf|otf|eot|woff|woff2)$">
    <IfModule mod_headers.c>
        SetEnvIf Origin "http(s)?://(www\.)?(google.com|staging.google.com|development.google.com|otherdomain.example|dev02.otherdomain.example)$" AccessControlAllowOrigin=$0
        Header add Access-Control-Allow-Origin %{AccessControlAllowOrigin}e env=AccessControlAllowOrigin
        Header merge Vary Origin
    </IfModule>
</FilesMatch>

Proper way of checking if row exists in table in PL/SQL block

IMO code with a stand-alone SELECT used to check to see if a row exists in a table is not taking proper advantage of the database. In your example you've got a hard-coded ID value but that's not how apps work in "the real world" (at least not in my world - yours may be different :-). In a typical app you're going to use a cursor to find data - so let's say you've got an app that's looking at invoice data, and needs to know if the customer exists. The main body of the app might be something like

FOR aRow IN (SELECT * FROM INVOICES WHERE DUE_DATE < TRUNC(SYSDATE)-60)
LOOP
  -- do something here
END LOOP;

and in the -- do something here you want to find if the customer exists, and if not print an error message.

One way to do this would be to put in some kind of singleton SELECT, as in

-- Check to see if the customer exists in PERSON

BEGIN
  SELECT 'TRUE'
    INTO strCustomer_exists
    FROM PERSON
    WHERE PERSON_ID = aRow.CUSTOMER_ID;
EXCEPTION
  WHEN NO_DATA_FOUND THEN
    strCustomer_exists := 'FALSE';
END;

IF strCustomer_exists = 'FALSE' THEN
  DBMS_OUTPUT.PUT_LINE('Customer does not exist!');
END IF;

but IMO this is relatively slow and error-prone. IMO a Better Way (tm) to do this is to incorporate it in the main cursor:

FOR aRow IN (SELECT i.*, p.ID AS PERSON_ID
               FROM INVOICES i
               LEFT OUTER JOIN PERSON p
                 ON (p.ID = i.CUSTOMER_PERSON_ID)
               WHERE DUE_DATA < TRUNC(SYSDATE)-60)
LOOP
  -- Check to see if the customer exists in PERSON

  IF aRow.PERSON_ID IS NULL THEN
    DBMS_OUTPUT.PUT_LINE('Customer does not exist!');
  END IF;
END LOOP;

This code counts on PERSON.ID being declared as the PRIMARY KEY on PERSON (or at least as being NOT NULL); the logic is that if the PERSON table is outer-joined to the query, and the PERSON_ID comes up as NULL, it means no row was found in PERSON for the given CUSTOMER_ID because PERSON.ID must have a value (i.e. is at least NOT NULL).

Share and enjoy.

Select from multiple tables without a join?

You could try something like this:

SELECT ...
FROM (
    SELECT f1,f2,f3 FROM table1
    UNION
    SELECT f1,f2,f3 FROM table2
)
WHERE ...

How can I put an icon inside a TextInput in React Native?

This is working for me in ReactNative 0.60.4

View

<View style={styles.SectionStyle}>
    <Image
        source={require('../assets/images/ico-email.png')} //Change your icon image here
        style={styles.ImageStyle}
    />

    <TextInput
        style={{ flex: 1 }}
        placeholder="Enter Your Name Here"
        underlineColorAndroid="transparent"
    />
</View>

Styles

SectionStyle: {
    flexDirection: 'row',
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#fff',
    borderWidth: 0.5,
    borderColor: '#000',
    height: 40,
    borderRadius: 5,
    margin: 10,
},
ImageStyle: {
    padding: 10,
    margin: 5,
    height: 25,
    width: 25,
    resizeMode: 'stretch',
    alignItems: 'center',
}

How do I look inside a Python object?

If you want to look inside a live object, then python's inspect module is a good answer. In general, it works for getting the source code of functions that are defined in a source file somewhere on disk. If you want to get the source of live functions and lambdas that were defined in the interpreter, you can use dill.source.getsource from dill. It also can get the code for from bound or unbound class methods and functions defined in curries... however, you might not be able to compile that code without the enclosing object's code.

>>> from dill.source import getsource
>>> 
>>> def add(x,y):
...   return x+y
... 
>>> squared = lambda x:x**2
>>> 
>>> print getsource(add)
def add(x,y):
  return x+y

>>> print getsource(squared)
squared = lambda x:x**2

>>> 
>>> class Foo(object):
...   def bar(self, x):
...     return x*x+x
... 
>>> f = Foo()
>>> 
>>> print getsource(f.bar)
def bar(self, x):
    return x*x+x

>>> 

matplotlib does not show my drawings although I call pyplot.show()

After running your code include:

import pylab as p
p.show()

How do I remove a key from a JavaScript object?

If you are using Underscore.js or Lodash, there is a function 'omit' that will do it.
http://underscorejs.org/#omit

var thisIsObject= {
    'Cow' : 'Moo',
    'Cat' : 'Meow',
    'Dog' : 'Bark'
};
_.omit(thisIsObject,'Cow'); //It will return a new object

=> {'Cat' : 'Meow', 'Dog' : 'Bark'}  //result

If you want to modify the current object, assign the returning object to the current object.

thisIsObject = _.omit(thisIsObject,'Cow');

With pure JavaScript, use:

delete thisIsObject['Cow'];

Another option with pure JavaScript.

thisIsObject.cow = undefined;

thisIsObject = JSON.parse(JSON.stringify(thisIsObject ));

android.content.res.Resources$NotFoundException: String resource ID #0x0

Replace

dateTime.setText(app.getTotalDl());

With

dateTime.setText(""+app.getTotalDl());

Unable to compile class for JSP: The type java.util.Map$Entry cannot be resolved. It is indirectly referenced from required .class files

The class format of JDK8 has changed and thats the reason why Tomcat is not able to compile JSPs. Try to get a newer version of Tomcat.

I recently had the same problem. This is a bug in Tomcat, or rather, JDK 8 has a slightly different class file format than what prior-JDK8 versions had. This causes inconsistency and Tomcat is not able to compile JSPs in JDK8.

See following references:

How to set Linux environment variables with Ansible

Here's a quick local task to permanently set key/values on /etc/environment (which is system-wide, all users):

- name: populate /etc/environment
  lineinfile:
    dest: "/etc/environment"
    state: present
    regexp: "^{{ item.key }}="
    line: "{{ item.key }}={{ item.value}}"
  with_items: "{{ os_environment }}"

and the vars for it:

os_environment:
  - key: DJANGO_SETTINGS_MODULE 
    value : websec.prod_settings  
  - key: DJANGO_SUPER_USER 
    value : admin

and, yes, if you ssh out and back in, env shows the new environment variables.

How do I lowercase a string in Python?

How to convert string to lowercase in Python?

Is there any way to convert an entire user inputted string from uppercase, or even part uppercase to lowercase?

E.g. Kilometers --> kilometers

The canonical Pythonic way of doing this is

>>> 'Kilometers'.lower()
'kilometers'

However, if the purpose is to do case insensitive matching, you should use case-folding:

>>> 'Kilometers'.casefold()
'kilometers'

Here's why:

>>> "Maße".casefold()
'masse'
>>> "Maße".lower()
'maße'
>>> "MASSE" == "Maße"
False
>>> "MASSE".lower() == "Maße".lower()
False
>>> "MASSE".casefold() == "Maße".casefold()
True

This is a str method in Python 3, but in Python 2, you'll want to look at the PyICU or py2casefold - several answers address this here.

Unicode Python 3

Python 3 handles plain string literals as unicode:

>>> string = '????????'
>>> string
'????????'
>>> string.lower()
'????????'

Python 2, plain string literals are bytes

In Python 2, the below, pasted into a shell, encodes the literal as a string of bytes, using utf-8.

And lower doesn't map any changes that bytes would be aware of, so we get the same string.

>>> string = '????????'
>>> string
'\xd0\x9a\xd0\xb8\xd0\xbb\xd0\xbe\xd0\xbc\xd0\xb5\xd1\x82\xd1\x80'
>>> string.lower()
'\xd0\x9a\xd0\xb8\xd0\xbb\xd0\xbe\xd0\xbc\xd0\xb5\xd1\x82\xd1\x80'
>>> print string.lower()
????????

In scripts, Python will object to non-ascii (as of Python 2.5, and warning in Python 2.4) bytes being in a string with no encoding given, since the intended coding would be ambiguous. For more on that, see the Unicode how-to in the docs and PEP 263

Use Unicode literals, not str literals

So we need a unicode string to handle this conversion, accomplished easily with a unicode string literal, which disambiguates with a u prefix (and note the u prefix also works in Python 3):

>>> unicode_literal = u'????????'
>>> print(unicode_literal.lower())
????????

Note that the bytes are completely different from the str bytes - the escape character is '\u' followed by the 2-byte width, or 16 bit representation of these unicode letters:

>>> unicode_literal
u'\u041a\u0438\u043b\u043e\u043c\u0435\u0442\u0440'
>>> unicode_literal.lower()
u'\u043a\u0438\u043b\u043e\u043c\u0435\u0442\u0440'

Now if we only have it in the form of a str, we need to convert it to unicode. Python's Unicode type is a universal encoding format that has many advantages relative to most other encodings. We can either use the unicode constructor or str.decode method with the codec to convert the str to unicode:

>>> unicode_from_string = unicode(string, 'utf-8') # "encoding" unicode from string
>>> print(unicode_from_string.lower())
????????
>>> string_to_unicode = string.decode('utf-8') 
>>> print(string_to_unicode.lower())
????????
>>> unicode_from_string == string_to_unicode == unicode_literal
True

Both methods convert to the unicode type - and same as the unicode_literal.

Best Practice, use Unicode

It is recommended that you always work with text in Unicode.

Software should only work with Unicode strings internally, converting to a particular encoding on output.

Can encode back when necessary

However, to get the lowercase back in type str, encode the python string to utf-8 again:

>>> print string
????????
>>> string
'\xd0\x9a\xd0\xb8\xd0\xbb\xd0\xbe\xd0\xbc\xd0\xb5\xd1\x82\xd1\x80'
>>> string.decode('utf-8')
u'\u041a\u0438\u043b\u043e\u043c\u0435\u0442\u0440'
>>> string.decode('utf-8').lower()
u'\u043a\u0438\u043b\u043e\u043c\u0435\u0442\u0440'
>>> string.decode('utf-8').lower().encode('utf-8')
'\xd0\xba\xd0\xb8\xd0\xbb\xd0\xbe\xd0\xbc\xd0\xb5\xd1\x82\xd1\x80'
>>> print string.decode('utf-8').lower().encode('utf-8')
????????

So in Python 2, Unicode can encode into Python strings, and Python strings can decode into the Unicode type.

Set textarea width to 100% in bootstrap modal

If i understand right this is what your looking for.

.form-control { width: 100%; }

See demo on JSFiddle.

sequelize findAll sort order in nodejs

If you want to sort data either in Ascending or Descending order based on particular column, using sequlize js, use the order method of sequlize as follows

// Will order the specified column by descending order
order: sequelize.literal('column_name order')
e.g. order: sequelize.literal('timestamp DESC')

How do I keep a label centered in WinForms?

The accepted answer didn't work for me for two reasons:

  1. I had BackColor set so setting AutoSize = false and Dock = Fill causes the background color to fill the whole form
  2. I couldn't have AutoSize set to false anyway because my label text was dynamic

Instead, I simply used the form's width and the width of the label to calculate the left offset:

MyLabel.Left = (this.Width - MyLabel.Width) / 2;

Create a date from day month and year with T-SQL

If you don't want to keep strings out of it, this works as well (Put it into a function):

DECLARE @Day int, @Month int, @Year int
SELECT @Day = 1, @Month = 2, @Year = 2008

SELECT DateAdd(dd, @Day-1, DateAdd(mm, @Month -1, DateAdd(yy, @Year - 2000, '20000101')))

What and where are the stack and heap?

Stack

  • Very fast access
  • Don't have to explicitly de-allocate variables
  • Space is managed efficiently by CPU, memory will not become fragmented
  • Local variables only
  • Limit on stack size (OS-dependent)
  • Variables cannot be resized

Heap

  • Variables can be accessed globally
  • No limit on memory size
  • (Relatively) slower access
  • No guaranteed efficient use of space, memory may become fragmented over time as blocks of memory are allocated, then freed
  • You must manage memory (you're in charge of allocating and freeing variables)
  • Variables can be resized using realloc()

How to get selected value of a html select with asp.net

<%@ Page Language="C#" AutoEventWireup="True" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">    
<head>
    <title> HtmlSelect Example </title>
    <script runat="server">
      void Button_Click (Object sender, EventArgs e)
      {
         Label1.Text = "Selected index: " + Select1.SelectedIndex.ToString()
                       + ", value: " + Select1.Value;    
      }    
   </script>    
</head>    
<body>    
   <form id="form1" runat="server">

      Select an item: 

      <select id="Select1" runat="server">    
         <option value="Text for Item 1" selected="selected"> Item 1 </option>
         <option value="Text for Item 2"> Item 2 </option>
         <option value="Text for Item 3"> Item 3 </option>
         <option value="Text for Item 4"> Item 4 </option>
      </select>

      <button onserverclick="Button_Click" runat="server" Text="Submit"/>

      <asp:Label id="Label1" runat="server"/>    
   </form>
</body>
</html>

Source from Microsoft. Hope this is helpful!

Is there a PowerShell "string does not contain" cmdlet or syntax?

If $arrayofStringsNotInterestedIn is an [array] you should use -notcontains:

Get-Content $FileName | foreach-object { `
   if ($arrayofStringsNotInterestedIn -notcontains $_) { $) }

or better (IMO)

Get-Content $FileName | where { $arrayofStringsNotInterestedIn -notcontains $_}

Start systemd service after specific service?

After= dependency is only effective when service including After= and service included by After= are both scheduled to start as part of your boot up.

Ex:

a.service
[Unit]
After=b.service

This way, if both a.service and b.service are enabled, then systemd will order b.service after a.service.

If I am not misunderstanding, what you are asking is how to start b.service when a.service starts even though b.service is not enabled.

The directive for this is Wants= or Requires= under [Unit].

website.service
[Unit]
Wants=mongodb.service
After=mongodb.service

The difference between Wants= and Requires= is that with Requires=, a failure to start b.service will cause the startup of a.service to fail, whereas with Wants=, a.service will start even if b.service fails. This is explained in detail on the man page of .unit.

What are the obj and bin folders (created by Visual Studio) used for?

One interesting fact about the obj directory: If you have publishing set up in a web project, the files that will be published are staged to obj\Release\Package\PackageTmp. If you want to publish the files yourself rather than use the integrated VS feature, you can grab the files that you actually need to deploy here, rather than pick through all the digital debris in the bin directory.

Change keystore password from no password to a non blank password

this way worked better for me:

echo y | keytool -storepasswd -storepass 123456 -keystore /tmp/IT-Root-CA.keystore -import -alias IT-Root-CA -file /etc/pki/ca-trust/source/anchors/IT-Root-CA.crt

machine running:

[root@rhel80-68]# cat /etc/redhat-release 
Red Hat Enterprise Linux release 8.1 (Ootpa)

Convert INT to DATETIME (SQL)

you need to convert to char first because converting to int adds those days to 1900-01-01

select CONVERT (datetime,convert(char(8),rnwl_efctv_dt ))

here are some examples

select CONVERT (datetime,5)

1900-01-06 00:00:00.000

select CONVERT (datetime,20100101)

blows up, because you can't add 20100101 days to 1900-01-01..you go above the limit

convert to char first

declare @i int
select @i = 20100101
select CONVERT (datetime,convert(char(8),@i))

Parsing a comma-delimited std::string

Something less verbose, std and takes anything separated by a comma.

stringstream ss( "1,1,1,1, or something else ,1,1,1,0" );
vector<string> result;

while( ss.good() )
{
    string substr;
    getline( ss, substr, ',' );
    result.push_back( substr );
}

Increment counter with loop

Try the following:

<c:set var="count" value="0" scope="page" />

//in your loops
<c:set var="count" value="${count + 1}" scope="page"/>

How to connect to MongoDB in Windows?

The error occurs when trying to run mongo.exe WITHOUT having executed mongod.exe. The following batch script solved the problem:

@echo off
cd C:\mongodb\bin\
start mongod.exe
start mongo.exe
exit

jquery change button color onclick

You have to include the jquery framework in your document head from a cdn for example:

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js" type="text/javascript"></script>

Then you have to include a own script for example:

(function( $ ) {

  $(document).ready(function(){
      $('input').click(function() {
          $(this).css('background-color', 'green');
      }
  });


  $(window).load(function() { 
  });

})( jQuery );

This part is a mapping of the $ to jQuery, so actually it is jQuery('selector').function();

(function( $ ) {

})( jQuery );

Here you can find die api of jquery where all functions are listed with examples and explanation: http://api.jquery.com/

Twitter Bootstrap: div in container with 100% height

It is very simple. You can use

.fill .map 
{
  min-height: 100vh;
}

You can change height according to your requirement.

How to use if, else condition in jsf to display image

Instead of using the "c" tags, you could also do the following:

<h:outputLink value="Images/thumb_02.jpg" target="_blank" rendered="#{not empty user or user.userId eq 0}" />
<h:graphicImage value="Images/thumb_02.jpg" rendered="#{not empty user or user.userId eq 0}" />

<h:outputLink value="/DisplayBlobExample?userId=#{user.userId}" target="_blank" rendered="#{not empty user and user.userId neq 0}" />
<h:graphicImage value="/DisplayBlobExample?userId=#{user.userId}" rendered="#{not empty user and user.userId neq 0}"/>

I think that's a little more readable alternative to skuntsel's alternative answer and is utilizing the JSF rendered attribute instead of nesting a ternary operator. And off the answer, did you possibly mean to put your image in between the anchor tags so the image is clickable?

Define preprocessor macro through CMake?

For a long time, CMake had the add_definitions command for this purpose. However, recently the command has been superseded by a more fine grained approach (separate commands for compile definitions, include directories, and compiler options).

An example using the new add_compile_definitions:

add_compile_definitions(OPENCV_VERSION=${OpenCV_VERSION})
add_compile_definitions(WITH_OPENCV2)

Or:

add_compile_definitions(OPENCV_VERSION=${OpenCV_VERSION} WITH_OPENCV2)

The good part about this is that it circumvents the shabby trickery CMake has in place for add_definitions. CMake is such a shabby system, but they are finally finding some sanity.

Find more explanation on which commands to use for compiler flags here: https://cmake.org/cmake/help/latest/command/add_definitions.html

Likewise, you can do this per-target as explained in Jim Hunziker's answer.

Proper way to assert type of variable in Python

Doing type('') is effectively equivalent to str and types.StringType

so type('') == str == types.StringType will evaluate to "True"

Note that Unicode strings which only contain ASCII will fail if checking types in this way, so you may want to do something like assert type(s) in (str, unicode) or assert isinstance(obj, basestring), the latter of which was suggested in the comments by 007Brendan and is probably preferred.

isinstance() is useful if you want to ask whether an object is an instance of a class, e.g:

class MyClass: pass

print isinstance(MyClass(), MyClass) # -> True
print isinstance(MyClass, MyClass()) # -> TypeError exception

But for basic types, e.g. str, unicode, int, float, long etc asking type(var) == TYPE will work OK.

jQuery - getting custom attribute from selected option

You're pretty close:

var myTag = $(':selected', element).attr("myTag");

How to remove a column from an existing table?

Generic:

ALTER TABLE table_name DROP COLUMN column_name;

In your case:

ALTER TABLE MEN DROP COLUMN Lname;

Calling a Sub and returning a value

You should be using a Property:

Private _myValue As String
Public Property MyValue As String
    Get
        Return _myValue
    End Get
    Set(value As String)
        _myValue = value
     End Set
End Property

Then use it like so:

MyValue = "Hello"
Console.write(MyValue)

Bootstrap 4 - Responsive cards in card-columns

I realize this question was posted a while ago; nonetheless, Bootstrap v4.0 has card layout support out of the box. You can find the documentation here: Bootstrap Card Layouts.

I've gotten back into using Bootstrap for a recent project that relies heavily on the card layout UI. I've found success with the following implementation across the standard breakpoints:

_x000D_
_x000D_
<link href="https://unpkg.com/[email protected]/css/tachyons.min.css" rel="stylesheet"/>_x000D_
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<div class="flex justify-center" id="cars" v-cloak>_x000D_
    <!-- RELEVANT MARKUP BEGINS HERE -->_x000D_
    <div class="container mh0 w-100">_x000D_
        <div class="page-header text-center mb5">_x000D_
            <h1 class="avenir text-primary mb-0">Cars</h1>_x000D_
            <p class="text-secondary">Add and manage your cars for sale.</p>_x000D_
            <div class="header-button">_x000D_
                <button class="btn btn-outline-primary" @click="clickOpenAddCarModalButton">Add a car for sale</button>_x000D_
            </div>_x000D_
        </div>_x000D_
        <div class="container pa0 flex justify-center">_x000D_
            <div class="listings card-columns">_x000D_
                <div class="card mv2">_x000D_
                    <img src="https://farm4.staticflickr.com/3441/3361756632_8d84aa8560.jpg" class="card-img-top"_x000D_
                        alt="Mazda hatchback">_x000D_
                    <div class="card-body">_x000D_
                        <h5 class="card-title">Card title</h5>_x000D_
                        <p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's_x000D_
                            content._x000D_
                        </p>_x000D_
                        <a href="#" class="btn btn-primary">Go somewhere</a>_x000D_
                    </div>_x000D_
                    <div class="card-footer">_x000D_
                        buttons here_x000D_
                    </div>_x000D_
                </div>_x000D_
                <div class="card mv2">_x000D_
                    <img src="https://farm4.staticflickr.com/3441/3361756632_8d84aa8560.jpg" class="card-img-top"_x000D_
                        alt="Mazda hatchback">_x000D_
                    <div class="card-body">_x000D_
                        <h5 class="card-title">Card title</h5>_x000D_
                        <p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's_x000D_
                            content._x000D_
                        </p>_x000D_
                        <a href="#" class="btn btn-primary">Go somewhere</a>_x000D_
                    </div>_x000D_
                    <div class="card-footer">_x000D_
                        buttons here_x000D_
                    </div>_x000D_
                </div>_x000D_
                <div class="card mv2">_x000D_
                    <img src="https://farm4.staticflickr.com/3441/3361756632_8d84aa8560.jpg" class="card-img-top"_x000D_
                        alt="Mazda hatchback">_x000D_
                    <div class="card-body">_x000D_
                        <h5 class="card-title">Card title</h5>_x000D_
                        <p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's_x000D_
                            content._x000D_
                        </p>_x000D_
                        <a href="#" class="btn btn-primary">Go somewhere</a>_x000D_
                    </div>_x000D_
                    <div class="card-footer">_x000D_
                        buttons here_x000D_
                    </div>_x000D_
                </div>_x000D_
                <div class="card mv2">_x000D_
                    <img src="https://farm4.staticflickr.com/3441/3361756632_8d84aa8560.jpg" class="card-img-top"_x000D_
                        alt="Mazda hatchback">_x000D_
                    <div class="card-body">_x000D_
                        <h5 class="card-title">Card title</h5>_x000D_
                        <p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's_x000D_
                            content._x000D_
                        </p>_x000D_
                        <a href="#" class="btn btn-primary">Go somewhere</a>_x000D_
                    </div>_x000D_
                    <div class="card-footer">_x000D_
                        buttons here_x000D_
                    </div>_x000D_
                </div>_x000D_
                <div class="card mv2">_x000D_
                    <img src="https://farm4.staticflickr.com/3441/3361756632_8d84aa8560.jpg" class="card-img-top"_x000D_
                        alt="Mazda hatchback">_x000D_
                    <div class="card-body">_x000D_
                        <h5 class="card-title">Card title</h5>_x000D_
                        <p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's_x000D_
                            content._x000D_
                        </p>_x000D_
                        <a href="#" class="btn btn-primary">Go somewhere</a>_x000D_
                    </div>_x000D_
                    <div class="card-footer">_x000D_
                        buttons here_x000D_
                    </div>_x000D_
                </div>_x000D_
            </div>_x000D_
        </div>_x000D_
    </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

After trying both the Bootstrap .card-group and .card-deck card layout classes with quirky results at best across the standard breakpoints, I finally decided to give the .card-columns class a shot. And it worked!

Your results may vary, but .card-columns seems to be the most stable implementation here.

How to force R to use a specified factor level as reference in a regression?

For those looking for a dplyr/tidyverse version. Building on Gavin Simpson solution:

# Create DF
set.seed(123)
x <- rnorm(100)
DF <- data.frame(x = x,
                 y = 4 + (1.5*x) + rnorm(100, sd = 2),
                 b = gl(5, 20))

# Change reference level
DF = DF %>% mutate(b = relevel(b, 3))

m2 <- lm(y ~ x + b, data = DF)
summary(m2)

calling a java servlet from javascript

Sorry, I read jsp not javascript. You need to do something like (note that this is a relative url and may be different depending on the url of the document this javascript is in):

document.location = 'path/to/servlet';

Where your servlet-mapping in web.xml looks something like this:

<servlet-mapping>
    <servlet-name>someServlet</servlet-name>
    <url-pattern>/path/to/servlet*</url-pattern>
</servlet-mapping>

Spring MVC Controller redirect using URL parameters instead of in response

This problem is caused (as others have stated) by model attributes being persisted into the query string - this is usually undesirable and is at risk of creating security holes as well as ridiculous query strings. My usual solution is to never use Strings for redirects in Spring MVC, instead use a RedirectView which can be configured not to expose model attributes (see: http://static.springsource.org/spring/docs/3.1.x/javadoc-api/org/springframework/web/servlet/view/RedirectView.html)

RedirectView(String url, boolean contextRelative, boolean http10Compatible, boolean exposeModelAttributes)

So I tend to have a util method which does a 'safe redirect' like:

public static RedirectView safeRedirect(String url) {
    RedirectView rv = new RedirectView(url);
    rv.setExposeModelAttributes(false);
    return rv;
}

The other option is to use bean configuration XML:

<bean id="myBean" class="org.springframework.web.servlet.view.RedirectView">
   <property name="exposeModelAttributes" value="false" />
   <property name="url" value="/myRedirect"/>
</bean>

Again, you could abstract this into its own class to avoid repetition (e.g. SafeRedirectView).


A note about 'clearing the model' - this is not the same as 'not exposing the model' in all circumstances. One site I worked on had a lot of filters which added things to the model, this meant that clearing the model before redirecting would not prevent a long query string. I would also suggest that 'not exposing model attributes' is a more semantic approach than 'clearing the model before redirecting'.

Combine two columns and add into one new column

Did you check the string concatenation function? Something like:

update table_c set column_a = column_b || column_c 

should work. More here

MSOnline can't be imported on PowerShell (Connect-MsolService error)

The solution with copying 32-bit libs over to 64-bit did not work for me. What worked was unchecking Target Platform Prefer 32-bit check mark in project properties.

Log.INFO vs. Log.DEBUG

I usually try to use it like this:

  • DEBUG: Information interesting for Developers, when trying to debug a problem.
  • INFO: Information interesting for Support staff trying to figure out the context of a given error
  • WARN to FATAL: Problems and Errors depending on level of damage.

Pure JavaScript equivalent of jQuery's $.ready() - how to call a function when the page/DOM is ready for it

document.ondomcontentready=function(){} should do the trick, but it doesn't have full browser compatibility.

Seems like you should just use jQuery min

How to go from one page to another page using javascript?

For MVC developers, to redirect a browser using javascript:

window.location.href = "@Url.Action("Action", "Controller")";

Iterate over model instance field names and values in template

Just an edit of @wonder

def to_dict(obj, exclude=[]):
    tree = {}
    for field in obj._meta.fields + obj._meta.many_to_many:
        if field.name in exclude or \
           '%s.%s' % (type(obj).__name__, field.name) in exclude:
            continue
        try :
            value = getattr(obj, field.name)
        except obj.DoesNotExist as e:
            value = None
        except ObjectDoesNotExist as e:
            value = None
            continue
        if type(field) in [ForeignKey, OneToOneField]:
            tree[field.name] = to_dict(value, exclude=exclude)
        elif isinstance(field, ManyToManyField):
            vs = []
            for v in value.all():
                vs.append(to_dict(v, exclude=exclude))
            tree[field.name] = vs
        else:
            tree[field.name] = obj.serializable_value(field.name)
    return tree

Let Django handle all the other fields other than the related fields. I feel that is more stable

Insert data using Entity Framework model

I'm using EF6, and I find something strange,

Suppose Customer has constructor with parameter ,

if I use new Customer(id, "name"), and do

 using (var db = new EfContext("name=EfSample"))
 {
    db.Customers.Add( new Customer(id, "name") );
    db.SaveChanges();
 }

It run through without error, but when I look into the DataBase, I find in fact that the data Is NOT be Inserted,

But if I add the curly brackets, use new Customer(id, "name"){} and do

 using (var db = new EfContext("name=EfSample"))
 {
    db.Customers.Add( new Customer(id, "name"){} );
    db.SaveChanges();
 }

the data will then actually BE Inserted,

seems the Curly Brackets make the difference, I guess that only when add Curly Brackets, entity framework will recognize this is a real concrete data.

QuotaExceededError: Dom exception 22: An attempt was made to add something to storage that exceeded the quota

This question and answer helped me solve a specific problem with signing up new users in Parse.

Because the signUp( attrs, options ) function uses local storage to persist the session, if a user is in private browsing mode it throws the "QuotaExceededError: DOM Exception 22: An attempt was made to add something to storage that exceeded the quota." exception and the success/error functions are never called.

In my case, because the error function is never called it initially appeared to be an issue with firing the click event on the submit or the redirect defined on success of sign up.

Including a warning for users resolved the issue.

Parse Javascript SDK Reference https://parse.com/docs/js/api/classes/Parse.User.html#methods_signUp

Signs up a new user with a username (or email) and password. This will create a new Parse.User on the server, and also persist the session in localStorage so that you can access the user using {@link #current}.

How to store .pdf files into MySQL as BLOBs using PHP?

EDITED TO ADD: The following code is outdated and won't work in PHP 7. See the note towards the bottom of the answer for more details.


Assuming a table structure of an integer ID and a blob DATA column, and assuming MySQL functions are being used to interface with the database, you could probably do something like this:

$result = mysql_query 'INSERT INTO table (
    data
) VALUES (
    \'' . mysql_real_escape_string (file_get_contents ('/path/to/the/file/to/store.pdf')) . '\'
);';

A word of warning though, storing blobs in databases is generally not considered to be the best idea as it can cause table bloat and has a number of other problems associated with it. A better approach would be to move the file somewhere in the filesystem where it can be retrieved, and store the path to the file in the database instead of the file itself.

Also, using mysql_* function calls is discouraged as those methods are effectively deprecated and aren't really built with versions of MySQL newer than 4.x in mind. You should switch to mysqli or PDO instead.

UPDATE: mysql_* functions are deprecated in PHP 5.x and are REMOVED COMPLETELY IN PHP 7! You now have no choice but to switch to a more modern Database Abstraction (MySQLI, PDO). I've decided to leave the original answer above intact for historical reasons but don't actually use it

Here's how to do it with mysqli in procedural mode:

$result = mysqli_query ($db, 'INSERT INTO table (
    data
) VALUES (
    \'' . mysqli_real_escape_string (file_get_contents ('/path/to/the/file/to/store.pdf'), $db) . '\'
);');

The ideal way of doing it is with MySQLI/PDO prepared statements.

Mysql 1050 Error "Table already exists" when in fact, it does not

I've just had the same error but I knew the table already existed and wanted to add to it. I'm adding my answer as this question comes up as no.1 for me on google when looking for the same error but for a slightly different scenario. Basically I needed to tick

"Add DROP TABLE / VIEW / PROCEDURE / FUNCTION / EVENT / TRIGGER statement"

And this solved the error for me.

how to add json library

You can also install simplejson.

If you have pip (see https://pypi.python.org/pypi/pip) as your Python package manager you can install simplejson with:

 pip install simplejson

This is similar to the comment of installing with easy_install, but I prefer pip to easy_install as you can easily uninstall in pip with "pip uninstall package".

Looping through JSON with node.js

If you want to avoid blocking, which is only necessary for very large loops, then wrap the contents of your loop in a function called like this: process.nextTick(function(){<contents of loop>}), which will defer execution until the next tick, giving an opportunity for pending calls from other asynchronous functions to be processed.

What do the result codes in SVN mean?

You can always get a list by running:

svn status --help

Best practice for instantiating a new Android Fragment

While @yydl gives a compelling reason on why the newInstance method is better:

If Android decides to recreate your Fragment later, it's going to call the no-argument constructor of your fragment. So overloading the constructor is not a solution.

it's still quite possible to use a constructor. To see why this is, first we need to see why the above workaround is used by Android.

Before a fragment can be used, an instance is needed. Android calls YourFragment() (the no arguments constructor) to construct an instance of the fragment. Here any overloaded constructor that you write will be ignored, as Android can't know which one to use.

In the lifetime of an Activity the fragment gets created as above and destroyed multiple times by Android. This means that if you put data in the fragment object itself, it will be lost once the fragment is destroyed.

To workaround, android asks that you store data using a Bundle (calling setArguments()), which can then be accessed from YourFragment. Argument bundles are protected by Android, and hence are guaranteed to be persistent.

One way to set this bundle is by using a static newInstance method:

public static YourFragment newInstance (int data) {
    YourFragment yf = new YourFragment()
    /* See this code gets executed immediately on your object construction */
    Bundle args = new Bundle();
    args.putInt("data", data);
    yf.setArguments(args);
    return yf;
}

However, a constructor:

public YourFragment(int data) {
    Bundle args = new Bundle();
    args.putInt("data", data);
    setArguments(args);
}

can do exactly the same thing as the newInstance method.

Naturally, this would fail, and is one of the reasons Android wants you to use the newInstance method:

public YourFragment(int data) {
    this.data = data; // Don't do this
}

As further explaination, here's Android's Fragment Class:

/**
 * Supply the construction arguments for this fragment.  This can only
 * be called before the fragment has been attached to its activity; that
 * is, you should call it immediately after constructing the fragment.  The
 * arguments supplied here will be retained across fragment destroy and
 * creation.
 */
public void setArguments(Bundle args) {
    if (mIndex >= 0) {
        throw new IllegalStateException("Fragment already active");
    }
    mArguments = args;
}

Note that Android asks that the arguments be set only at construction, and guarantees that these will be retained.

EDIT: As pointed out in the comments by @JHH, if you are providing a custom constructor that requires some arguments, then Java won't provide your fragment with a no arg default constructor. So this would require you to define a no arg constructor, which is code that you could avoid with the newInstance factory method.

EDIT: Android doesn't allow using an overloaded constructor for fragments anymore. You must use the newInstance method.

Inserting HTML into a div

Using JQuery would take care of that browser inconsistency. With the jquery library included in your project simply write:

$('#yourDivName').html('yourtHTML');

You may also consider using:

$('#yourDivName').append('yourtHTML');

This will add your gallery as the last item in the selected div. Or:

$('#yourDivName').prepend('yourtHTML');

This will add it as the first item in the selected div.

See the JQuery docs for these functions:

Hibernate Union alternatives

A view is a better approach but since hql typically returns a List or Set... you can do list_1.addAll(list_2). Totally sucks compared to a union but should work.

cannot find zip-align when publishing app

zipalign was moved to build-tools\19.1.0 and build-tools\20.0.0, I assume you should use one of them in depend of your target SDK

How to get the instance id from within an ec2 instance?

FWIW I wrote a FUSE filesystem to provide access to the EC2 metadata service: https://bitbucket.org/dgc/ec2mdfs . I run this on all custom AMIs; it allows me to use this idiom: cat /ec2/meta-data/ami-id

How can I get the full object in Node.js's console.log(), rather than '[Object]'?

You need to use util.inspect():

const util = require('util')

console.log(util.inspect(myObject, {showHidden: false, depth: null}))

// alternative shortcut
console.log(util.inspect(myObject, false, null, true /* enable colors */))

Outputs

{ a: 'a',  b: { c: 'c', d: { e: 'e', f: { g: 'g', h: { i: 'i' } } } } }

See util.inspect() docs.

Spring data jpa- No bean named 'entityManagerFactory' is defined; Injection of autowired dependencies failed

I had the same problem and got it resolved by deleting .m2 maven repo (C:\Users\user\ .m2)

How to replace a hash key with another key

hash.each {|k,v| hash.delete(k) && hash[k[1..-1]]=v if k[0,1] == '_'}

Windows batch script to move files

move c:\Sourcefoldernam\*.* e:\destinationFolder

^ This did not work for me for some reason

But when I tried using quotation marks, it suddenly worked:

move "c:\Sourcefoldernam\*.*" "e:\destinationFolder"

I think its because my directory had spaces in one of the folders. So if it doesn't work for you, try with quotation marks!

How to change the background color of a UIButton while it's highlighted?

extension UIButton {
    func setBackgroundColor(color: UIColor, forState: UIControl.State) {
        let size = CGSize(width: 1, height: 1)
        UIGraphicsBeginImageContext(size)
        let context = UIGraphicsGetCurrentContext()
        context?.setFillColor(color.cgColor)
        context?.fill(CGRect(origin: CGPoint.zero, size: size))
        let colorImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        setBackgroundImage(colorImage, for: forState)
    }

}

Swift 5 , thanks @Maverick

Find methods calls in Eclipse project

Select mymethod() and press ctrl+alt+h.

To see some detailed Information about any method you can use this by selecting that particular Object or method and right click. you can see the "OpenCallHierarchy" (Ctrl+Alt+H). Like that many tools are there to make your work Easier like "Quick Outline" (Ctrl+O) to view the Datatypes and methods declared in a particular .java file.

To know more about this, refer this eclipse Reference

Style disabled button with CSS

I think you should be able to select a disabled button using the following:

button[disabled=disabled], button:disabled {
    // your css rules
}

How do I capture the output of a script if it is being ran by the task scheduler?

Example how to run program and write stdout and stderr to file with timestamp:

cmd /c ""C:\Program Files (x86)\program.exe" -param fooo >> "c:\dir space\Log_%date:~10,4%%date:~4,2%%date:~7,2%_%time:~0,2%%time:~3,2%%time:~6,2%.txt" 2>&1"

Key part is to double quote whole part behind cmd /c and inside it use double quotes as usual. Also note that date is locale dependent, this example works using US locale.

How to divide flask app into multiple py files?

This task can be accomplished without blueprints and tricky imports using Centralized URL Map

app.py

import views
from flask import Flask

app = Flask(__name__)

app.add_url_rule('/', view_func=views.index)
app.add_url_rule('/other', view_func=views.other)

if __name__ == '__main__':
    app.run(debug=True, use_reloader=True)

views.py

from flask import render_template

def index():
    return render_template('index.html')

def other():
    return render_template('other.html')

Git: "Corrupt loose object"

simply running a git prune fixed this issue for me

Can an html element have multiple ids?

No. While the definition from w3c for HTML 4 doesn't seem to explicitly cover your question, the definition of the name and id attribute says no spaces in the identifier:

ID and NAME tokens must begin with a letter ([A-Za-z]) and may be followed by any number of letters, digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods (".").

Multiple axis line chart in excel

It is possible to get both the primary and secondary axes on one side of the chart by designating the secondary axis for one of the series.

To get the primary axis on the right side with the secondary axis, you need to set to "High" the Axis Labels option in the Format Axis dialog box for the primary axis.

To get the secondary axis on the left side with the primary axis, you need to set to "Low" the Axis Labels option in the Format Axis dialog box for the secondary axis.

I know of no way to get a third set of axis labels on a single chart. You could fake in axis labels & ticks with text boxes and lines, but it would be hard to get everything aligned correctly.

The more feasible route is that suggested by zx8754: Create a second chart, turning off titles, left axes, etc. and lay it over the first chart. See my very crude mockup which hasn't been fine-tuned yet.

three axis labels chart

How to connect to my http://localhost web server from Android Emulator

The localhost refers to the device on which the code is running, in this case the emulator.

If you want to refer to the computer which is running the Android simulator, use the IP address 10.0.2.2 instead.

enter image description here

You can read more from here.

Cast to generic type in C#

To convert any type object to a generic type T, the trick is to first assign to an object of any higher type then cast that to the generic type.

object temp = otherTypeObject;
T result = (T)temp;

What is the difference between C and embedded C?

C is a only programming language its used in system programming. but embedded C is used to implement the projects like real time applications

How to use Git and Dropbox together?

I have faced a similar issue and have created a small script for the same. The idea is to use Dropbox with Git as simply as possible. Currently, I have quickly implemented Ruby code, and I will soon add more.

The script is accessible at https://github.com/nuttylabs/box-git.

Why can't Python import Image from PIL?

do from PIL import Image, ImageTk

Eclipse 3.5 Unable to install plugins

I had a similar problem setting up eclipse in the office. I had set up the for HTTP, HTTPS and SOCKS in:

Window>pref>general>network connections

Clearing the proxy settings for SOCKS fixed the problem for me.

Is there a java setting for disabling certificate validation?

Not exactly a setting but you can override the default TrustManager and HostnameVerifier to accept anything. Not a safe approach but in your situation, it can be acceptable.

Complete example : Fix certificate problem in HTTPS

How to store decimal values in SQL Server?

You should use is as follows:

DECIMAL(m,a)

m is the number of total digits your decimal can have.

a is the max number of digits you can have after the decimal point.

http://www.tsqltutorials.com/datatypes.php has descriptions for all the datatypes.

How to deal with INSTALL_PARSE_FAILED_INCONSISTENT_CERTIFICATES without uninstall?

This is the command to uninstall the app from device using adb:

adb uninstall <package name>

How can I modify the size of column in a MySQL table?

ALTER TABLE <tablename> CHANGE COLUMN <colname> <colname> VARCHAR(65536);

You have to list the column name twice, even if you aren't changing its name.

Note that after you make this change, the data type of the column will be MEDIUMTEXT.


Miky D is correct, the MODIFY command can do this more concisely.


Re the MEDIUMTEXT thing: a MySQL row can be only 65535 bytes (not counting BLOB/TEXT columns). If you try to change a column to be too large, making the total size of the row 65536 or greater, you may get an error. If you try to declare a column of VARCHAR(65536) then it's too large even if it's the only column in that table, so MySQL automatically converts it to a MEDIUMTEXT data type.

mysql> create table foo (str varchar(300));
mysql> alter table foo modify str varchar(65536);
mysql> show create table foo;
CREATE TABLE `foo` (
  `str` mediumtext
) ENGINE=MyISAM DEFAULT CHARSET=latin1
1 row in set (0.00 sec)

I misread your original question, you want VARCHAR(65353), which MySQL can do, as long as that column size summed with the other columns in the table doesn't exceed 65535.

mysql> create table foo (str1 varchar(300), str2 varchar(300));
mysql> alter table foo modify str2 varchar(65353);
ERROR 1118 (42000): Row size too large. 
The maximum row size for the used table type, not counting BLOBs, is 65535. 
You have to change some columns to TEXT or BLOBs

Showing empty view when ListView is empty

Activity code, its important to extend ListActivity.

package com.example.mylistactivity;

import android.app.ListActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import com.example.mylistactivity.R;

// It's important to extend ListActivity rather than Activity
public class MyListActivity extends ListActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.mylist);

        // shows list view
        String[] values = new String[] { "foo", "bar" };

        // shows empty view
        values = new String[] { };

        setListAdapter(new ArrayAdapter<String>(
                this,
                android.R.layout.simple_list_item_1,
                android.R.id.text1,
                values));
    }
}

Layout xml, the id in both views are important.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <!-- the android:id is important -->
    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"/>

    <!-- the android:id is important -->
    <TextView
        android:id="@android:id/empty"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:text="i am empty"/>
</LinearLayout>

Initializing default values in a struct

Yes. bar.a and bar.b are set to true, but bar.c is undefined. However, certain compilers will set it to false.

See a live example here: struct demo

According to C++ standard Section 8.5.12:

if no initialization is performed, an object with automatic or dynamic storage duration has indeterminate value

For primitive built-in data types (bool, char, wchar_t, short, int, long, float, double, long double), only global variables (all static storage variables) get default value of zero if they are not explicitly initialized.

If you don't really want undefined bar.c to start with, you should also initialize it like you did for bar.a and bar.b.

How do I compare two DateTime objects in PHP 5.2.8?

From the official documentation:

As of PHP 5.2.2, DateTime objects can be compared using comparison operators.

$date1 = new DateTime("now");
$date2 = new DateTime("tomorrow");

var_dump($date1 == $date2); // false
var_dump($date1 < $date2); // true
var_dump($date1 > $date2); // false

For PHP versions before 5.2.2 (actually for any version), you can use diff.

$datetime1 = new DateTime('2009-10-11'); // 11 October 2013
$datetime2 = new DateTime('2009-10-13'); // 13 October 2013

$interval = $datetime1->diff($datetime2);
echo $interval->format('%R%a days'); // +2 days

ng if with angular for string contains

All javascript methods are applicable with angularjs because angularjs itself is a javascript framework so you can use indexOf() inside angular directives

<li ng-repeat="select in Items">   
         <foo ng-repeat="newin select.values">
<span ng-if="newin.label.indexOf(x) !== -1">{{newin.label}}</span></foo>
</li>
//where x is your character to be found

Iterating through a Collection, avoiding ConcurrentModificationException when removing objects in a loop

One solution could be to rotate the list and remove the first element to avoid the ConcurrentModificationException or IndexOutOfBoundsException

int n = list.size();
for(int j=0;j<n;j++){
    //you can also put a condition before remove
    list.remove(0);
    Collections.rotate(list, 1);
}
Collections.rotate(list, -1);

how to insert a new line character in a string to PrintStream then use a scanner to re-read the file

The linefeed character \n is not the line separator in certain operating systems (such as windows, where it's "\r\n") - my suggestion is that you use \r\n instead, then it'll both see the line-break with only \n and \r\n, I've never had any problems using it.

Also, you should look into using a StringBuilder instead of concatenating the String in the while-loop at BookCatalog.toString(), it is a lot more effective. For instance:

public String toString() {
        BookNode current = front;
        StringBuilder sb = new StringBuilder();
        while (current!=null){
            sb.append(current.getData().toString()+"\r\n ");
            current = current.getNext();
        }
        return sb.toString();
}

How do I fix the error "Only one usage of each socket address (protocol/network address/port) is normally permitted"?

ListenForClients is getting invoked twice (on two different threads) - once from the constructor, once from the explicit method call in Main. When two instances of the TcpListener try to listen on the same port, you get that error.

mssql '5 (Access is denied.)' error during restoring database

I tried the above scenario and got the same error 5 (access denied). I did a deep dive and found that the file .bak should have access to the SQL service account. If you are not sure, type services.msc in Start -> Run then check for SQL Service logon account.

Then go to the file, right-click and select Security tab in Properties, then edit to add the new user.

Finally then give full permission to it in order to give full access.

Then from SSMS try to restore the backup.

IIS Express gives Access Denied error when debugging ASP.NET MVC

I used Jason's answer but wanted to clarify how to get in to properties.

  1. Select project in Solution Explorer

enter image description here

  1. F4 to get to properties (different than the right click properties)
  2. Change Windows Authentication to Enabled

enter image description here

RegExp matching string not starting with my

^(?!my)\w+$

should work.

It first ensures that it's not possible to match my at the start of the string, and then matches alphanumeric characters until the end of the string. Whitespace anywhere in the string will cause the regex to fail. Depending on your input you might want to either strip whitespace in the front and back of the string before passing it to the regex, or use add optional whitespace matchers to the regex like ^\s*(?!my)(\w+)\s*$. In this case, backreference 1 will contain the name of the variable.

And if you need to ensure that your variable name starts with a certain group of characters, say [A-Za-z_], use

^(?!my)[A-Za-z_]\w*$

Note the change from + to *.

Include php files when they are in different folders

None of the above answers fixed this issue for me. I did it as following (Laravel with Ubuntu server):

<?php
     $footerFile = '/var/www/website/main/resources/views/emails/elements/emailfooter.blade.php';
     include($footerFile);
?>

PDO error message?

Try this instead:

print_r($sth->errorInfo());

Add this before your prepare:

$this->pdo->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING );

This will change the PDO error reporting type and cause it to emit a warning whenever there is a PDO error. It should help you track it down, although your errorInfo should have bet set.

What's the difference between next() and nextLine() methods from Scanner class?

From the documentation for Scanner:

A Scanner breaks its input into tokens using a delimiter pattern, which by default matches whitespace.

From the documentation for next():

A complete token is preceded and followed by input that matches the delimiter pattern.

Could not open a connection to your authentication agent

I faced the same problem for Linux, and here is what I did:

Basically, the command ssh-agent starts the agent, but it doesn't really set the environment variables for it to run. It just outputs those variables to the shell.

You need to:

eval `ssh-agent`

and then do ssh-add. See Could not open a connection to your authentication agent.

How to check 'undefined' value in jQuery

when I am testing "typeof obj === undefined", the alert(typeof obj) returning object, even though obj is undefined. Since obj is type of Object its returning Object, not undefined.

So after hours of testing I opted below technique.

if(document.getElementById(obj) !== null){
//do...
}else{
//do...
}

I am not sure why the first technique didn't work.But I get done my work using this.

What is uintptr_t data type

uintptr_t is an unsigned integer type that is capable of storing a data pointer. Which typically means that it's the same size as a pointer.

It is optionally defined in C++11 and later standards.

A common reason to want an integer type that can hold an architecture's pointer type is to perform integer-specific operations on a pointer, or to obscure the type of a pointer by providing it as an integer "handle".

How to animate GIFs in HTML document?

I just ran into this... my gif didn't run on the server that I was testing on, but when I published the code it ran on my desktop just fine...

How to convert/parse from String to char in java?

If you want to parse a String to a char, whereas the String object represent more than one character, you just simply use the following expression: char c = (char) Integer.parseInt(s). Where s equals the String you want to parse. Most people forget that char's represent a 16-bit number, and thus can be a part of any numerical expression :)

Check div is hidden using jquery

You can use,

if (!$("#car-2").is(':visible'))
{
      alert('car 2 is hidden');
}

Cannot lower case button text in android studio

there are 3 ways to do it.

1.Add the following line on style.xml to change entire application

<item name="android:textAllCaps">false</item>

2.Use

android:textAllCaps="false"

in your layout-v21

mButton.setTransformationMethod(null);
  1. add this line under the element(button or edit text) in xml

android:textAllCaps="false"

regards

Maven: repository element was not specified in the POM inside distributionManagement?

The ID of the two repos are both localSnap; that's probably not what you want and it might confuse Maven.

If that's not it: There might be more repository elements in your POM. Search the output of mvn help:effective-pom for repository to make sure the number and place of them is what you expect.

SQL Server query to find all current database names

I don't recommend this method... but if you want to go wacky and strange:

EXEC sp_MSForEachDB 'SELECT ''?'' AS DatabaseName'

or

EXEC sp_MSForEachDB 'Print ''?'''

What is a C++ delegate?

An option for delegates in C++ that is not otherwise mentioned here is to do it C style using a function ptr and a context argument. This is probably the same pattern that many asking this question are trying to avoid. But, the pattern is portable, efficient, and is usable in embedded and kernel code.

class SomeClass
{
    in someMember;
    int SomeFunc( int);

    static void EventFunc( void* this__, int a, int b, int c)
    {
        SomeClass* this_ = static_cast< SomeClass*>( this__);

        this_->SomeFunc( a );
        this_->someMember = b + c;
    }
};

void ScheduleEvent( void (*delegateFunc)( void*, int, int, int), void* delegateContext);

    ...
    SomeClass* someObject = new SomeObject();
    ...
    ScheduleEvent( SomeClass::EventFunc, someObject);
    ...

Reset local repository branch to be just like remote repository HEAD

Setting your branch to exactly match the remote branch can be done in two steps:

git fetch origin
git reset --hard origin/master

Update @2020 (if you have main branch instead of master in remote repo)

git fetch origin
git reset --hard origin/main 

If you want to save your current branch's state before doing this (just in case), you can do:

git commit -a -m "Saving my work, just in case"
git branch my-saved-work

Now your work is saved on the branch "my-saved-work" in case you decide you want it back (or want to look at it later or diff it against your updated branch).

Note that the first example assumes that the remote repo's name is "origin" and that the branch named "master" in the remote repo matches the currently checked-out branch in your local repo.

BTW, this situation that you're in looks an awful lot like a common case where a push has been done into the currently checked out branch of a non-bare repository. Did you recently push into your local repo? If not, then no worries -- something else must have caused these files to unexpectedly end up modified. Otherwise, you should be aware that it's not recommended to push into a non-bare repository (and not into the currently checked-out branch, in particular).

Add button to a layout programmatically

This line:

layout = (LinearLayout) findViewById(R.id.statsviewlayout);

Looks for the "statsviewlayout" id in your current 'contentview'. Now you've set that here:

setContentView(new GraphTemperature(getApplicationContext()));

And i'm guessing that new "graphTemperature" does not set anything with that id.

It's a common mistake to think you can just find any view with findViewById. You can only find a view that is in the XML (or appointed by code and given an id).

The nullpointer will be thrown because the layout you're looking for isn't found, so

layout.addView(buyButton);

Throws that exception.

addition: Now if you want to get that view from an XML, you should use an inflater:

layout = (LinearLayout) View.inflate(this, R.layout.yourXMLYouWantToLoad, null);

assuming that you have your linearlayout in a file called "yourXMLYouWantToLoad.xml"

IIS AppPoolIdentity and file system write access permissions

Each application pool in IIs creates its own secure user folder with FULL read/write permission by default under c:\users. Open up your Users folder and see what application pool folders are there, right click, and check their rights for the application pool virtual account assigned. You should see your application pool account added already with read/write access assigned to its root and subfolders.

So that type of file storage access is automatically done and you should be able to write whatever you like there in the app pools user account folders without changing anything. That's why virtual user accounts for each application pool were created.

How do I import modules or install extensions in PostgreSQL 9.1+?

While Evan Carrol's answer is correct, please note that you need to install the postgresql contrib package in order for the CREATE EXTENSION command to work.

In Ubuntu 12.04 it would go like this:

sudo apt-get install postgresql-contrib

Restart the postgresql server:

sudo /etc/init.d/postgresql restart

All available extension are in:

/usr/share/postgresql/9.1/extension/

Now you can run the CREATE EXTENSION command.

Error:Execution failed for task ':app:processDebugResources'. > java.io.IOException: Could not delete folder "" in android studio

If you have another instance of Android Studio running, then kindly close it and then build the app. This worked in my case

Python - abs vs fabs

math.fabs() always returns float, while abs() may return integer.

Can I pass a JavaScript variable to another browser window?

Passing variables between the windows (if your windows are on the same domain) can be easily done via:

  1. Cookies
  2. localStorage. Just make sure your browser supports localStorage, and do the variable maintenance right (add/delete/remove) to keep localStorage clean.

MySql Error: Can't update table in stored function/trigger because it is already used by statement which invoked this stored function/trigger

I have the same problem and fix by add "new." before the field is updated. And I post full trigger here for someone to want to write a trigger

DELIMITER $$

USE `nc`$$

CREATE
    TRIGGER `nhachung_province_count_update` BEFORE UPDATE ON `nhachung` 
    FOR EACH ROW BEGIN

    DECLARE slug_province VARCHAR(128);
    DECLARE slug_district VARCHAR(128);

    IF old.status!=new.status THEN  /* neu doi status */
        IF new.status="Y" THEN
            UPDATE province SET `count`=`count`+1 WHERE id = new.district_id;
        ELSE 
            UPDATE province SET `count`=`count`-1 WHERE id = new.district_id;
        END IF;
    ELSEIF old.province_id!=new.province_id THEN /* neu doi province_id + district_id */

        UPDATE province SET `count`=`count`+1 WHERE id = new.province_id; /* province_id */
        UPDATE province SET `count`=`count`-1 WHERE id = old.province_id;
        UPDATE province SET `count`=`count`+1 WHERE id = new.district_id; /* district_id */
        UPDATE province SET `count`=`count`-1 WHERE id = old.district_id;

        SET slug_province = ( SELECT slug FROM province WHERE id= new.province_id LIMIT 0,1 );
        SET slug_district = ( SELECT slug FROM province WHERE id= new.district_id LIMIT 0,1 );
        SET new.prov_dist_url=CONCAT(slug_province, "/", slug_district);

    ELSEIF old.district_id!=new.district_id THEN 

        UPDATE province SET `count`=`count`+1 WHERE id = new.district_id;
        UPDATE province SET `count`=`count`-1 WHERE id = old.district_id;

        SET slug_province = ( SELECT slug FROM province WHERE id= new.province_id LIMIT 0,1 );
        SET slug_district = ( SELECT slug FROM province WHERE id= new.district_id LIMIT 0,1 );
        SET new.prov_dist_url=CONCAT(slug_province, "/", slug_district);

    END IF;


    END;
$$

DELIMITER ;

Hope this help someone

How to access Winform textbox control from another class?

public partial class Form1 : Form
{

    public static Form1 gui;
    public Form1()
    {
        InitializeComponent();
        gui = this;

    }
    public void WriteLog(string log)
    {
        this.Invoke(new Action(() => { txtbx_test1.Text += log; }));

    }
}
public class SomeAnotherClass
{
    public void Test()
    {
        Form1.gui.WriteLog("1234");
    }
}

I like this solution.

How can I expose more than 1 port with Docker?

Step1

In your Dockerfile, you can use the verb EXPOSE to expose multiple ports.
e.g.

EXPOSE 3000 80 443 22

Step2

You then would like to build an new image based on above Dockerfile.
e.g.

docker build -t foo:tag .

Step3

Then you can use the -p to map host port with the container port, as defined in above EXPOSE of Dockerfile.
e.g.

docker run -p 3001:3000 -p 23:22

In case you would like to expose a range of continuous ports, you can run docker like this:

docker run -it -p 7100-7120:7100-7120/tcp 

Select parent element of known element in Selenium

Let's consider your DOM as

<a>
    <!-- some other icons and texts -->
    <span>Close</span>
</a>

Now that you need to select parent tag 'a' based on <span> text, then use

driver.findElement(By.xpath("//a[.//span[text()='Close']]"));

Explanation: Select the node based on its child node's value

MySQL command line client for Windows

If you are looking for tools like the the mysql and mysqldump command line client for Windows for versions around mysql Ver 14.14 Distrib 5.6.13, for Win32 (x86) it seems to be in HOMEDRIVE:\Program Files (x86)\MySQL\MySQL Workbench version

This directory is also not placed in the path by default so you will need to add it to your PATH environment variable before you can easily run it from the command prompt.

Also, there is a mysql utilities console but it does not work for my needs. Below is a list of the capabilities on the mysql utilities console in case it works for you:

Utility           Description
----------------  ---------------------------------------------------------
mysqlauditadmin   audit log maintenance utility
mysqlauditgrep    audit log search utility
mysqldbcompare    compare databases for consistency
mysqldbcopy       copy databases from one server to another
mysqldbexport     export metadata and data from databases
mysqldbimport     import metadata and data from files
mysqldiff         compare object definitions among objects where the
                  difference is how db1.obj1 differs from db2.obj2
mysqldiskusage    show disk usage for databases
mysqlfailover     automatic replication health monitoring and failover
mysqlfrm          show CREATE TABLE from .frm files
mysqlindexcheck   check for duplicate or redundant indexes
mysqlmetagrep     search metadata
mysqlprocgrep     search process information
mysqlreplicate    establish replication with a master
mysqlrpladmin     administration utility for MySQL replication
mysqlrplcheck     check replication
mysqlrplshow      show slaves attached to a master
mysqlserverclone  start another instance of a running server
mysqlserverinfo   show server information
mysqluserclone    clone a MySQL user account to one or more new users

Node.js: printing to console without a trailing newline?

In Windows console (Linux, too), you should replace '\r' with its equivalent code \033[0G:

process.stdout.write('ok\033[0G');

This uses a VT220 terminal escape sequence to send the cursor to the first column.

Is there a better alternative than this to 'switch on type'?

You can create overloaded methods:

void Foo(A a) 
{ 
    a.Hop(); 
}

void Foo(B b) 
{ 
    b.Skip(); 
}

void Foo(object o) 
{ 
    throw new ArgumentException("Unexpected type: " + o.GetType()); 
}

And cast the argument to dynamic type in order to bypass static type checking:

Foo((dynamic)something);

Bash scripting missing ']'

add a space before the close bracket

Count number of tables in Oracle

try:

SELECT COUNT(*) FROM USER_TABLES;

Well i dont have oracle on my machine, i run mysql (OP comment)

at the time of writing, this site was great for testing on a variety of database types.

Android Transparent TextView?

If you are looking for something like the text view on the image on the pulse app do this

 android:background="#88000000"
android:textColor="#ffffff"

How do I set a path in Visual Studio?

Search MSDN for "How to: Set Environment Variables for Projects". (It's Project>Properties>Configuration Properties>Debugging "Environment" and "Merge Environment" properties for those who are in a rush.)

The syntax is NAME=VALUE and macros can be used (for example, $(OutDir)).

For example, to prepend C:\Windows\Temp to the PATH:

PATH=C:\WINDOWS\Temp;%PATH%

Similarly, to append $(TargetDir)\DLLS to the PATH:

PATH=%PATH%;$(TargetDir)\DLLS

Timestamp with a millisecond precision: How to save them in MySQL

You need to be at MySQL version 5.6.4 or later to declare columns with fractional-second time datatypes. Not sure you have the right version? Try SELECT NOW(3). If you get an error, you don't have the right version.

For example, DATETIME(3) will give you millisecond resolution in your timestamps, and TIMESTAMP(6) will give you microsecond resolution on a *nix-style timestamp.

Read this: https://dev.mysql.com/doc/refman/8.0/en/fractional-seconds.html

NOW(3) will give you the present time from your MySQL server's operating system with millisecond precision.

If you have a number of milliseconds since the Unix epoch, try this to get a DATETIME(3) value

FROM_UNIXTIME(ms * 0.001)

Javascript timestamps, for example, are represented in milliseconds since the Unix epoch.

(Notice that MySQL internal fractional arithmetic, like * 0.001, is always handled as IEEE754 double precision floating point, so it's unlikely you'll lose precision before the Sun becomes a white dwarf star.)

If you're using an older version of MySQL and you need subsecond time precision, your best path is to upgrade. Anything else will force you into doing messy workarounds.

If, for some reason you can't upgrade, you could consider using BIGINT or DOUBLE columns to store Javascript timestamps as if they were numbers. FROM_UNIXTIME(col * 0.001) will still work OK. If you need the current time to store in such a column, you could use UNIX_TIMESTAMP() * 1000

How to disable a link using only CSS?

Demo here
Try this one

$('html').on('click', 'a.Link', function(event){
    event.preventDefault();
});

MySQL Incorrect datetime value: '0000-00-00 00:00:00'

This is incredibly ugly, but it also fixed the problem quickly for me. Your table needs a unique key which you will use to fix the tainted columns. In this example, the primary key is called 'id' and the broken timestamp column is called 'BadColumn'.

  1. Select the IDs of the tainted columns.

    select id from table where BadColumn='0000-00-00 00:00:00'

  2. Collect the IDs into a comma-delimited string. Example: 1, 22, 33. I used an external wrapper for this (a Perl script) to quickly spit them all out.

  3. Use your list of IDs to update the old columns with a valid date (1971 through 2038).

    update table set BadColumn='2000-01-01 00:00:00' where id in (1, 22, 33)

Checking Bash exit status of several commands efficiently

Personally I much prefer to use a lightweight approach, as seen here;

yell() { echo "$0: $*" >&2; }
die() { yell "$*"; exit 111; }
try() { "$@" || die "cannot $*"; }
asuser() { sudo su - "$1" -c "${*:2}"; }

Example usage:

try apt-fast upgrade -y
try asuser vagrant "echo 'uname -a' >> ~/.profile"

How to insert pandas dataframe via mysqldb into database?

This should do the trick:

import pandas as pd
import pymysql
pymysql.install_as_MySQLdb()
from sqlalchemy import create_engine

# Create engine
engine = create_engine('mysql://USER_NAME_HERE:PASS_HERE@HOST_ADRESS_HERE/DB_NAME_HERE')

# Create the connection and close it(whether successed of failed)
with engine.begin() as connection:
  df.to_sql(name='INSERT_TABLE_NAME_HERE/INSERT_NEW_TABLE_NAME', con=connection, if_exists='append', index=False)

What is ModelState.IsValid valid for in ASP.NET MVC in NerdDinner?

All the model fields which have definite types, those should be validated when returned to Controller. If any of the model fields are not matching with their defined type, then ModelState.IsValid will return false. Because, These errors will be added in ModelState.

How to remove empty lines with or without whitespace in Python

Try list comprehension and string.strip():

>>> mystr = "L1\nL2\n\nL3\nL4\n  \n\nL5"
>>> mystr.split('\n')
['L1', 'L2', '', 'L3', 'L4', '  ', '', 'L5']
>>> [line for line in mystr.split('\n') if line.strip() != '']
['L1', 'L2', 'L3', 'L4', 'L5']

How can I do time/hours arithmetic in Google Spreadsheet?

Type the values in single cells, because google spreadsheet cant handle duration formats at all, in any way shape or form. Or you have to learn to make scripts and graduate as a chopper pilot. that is also a option.

Moment.js - tomorrow, today and yesterday

In Moment.js, the from() method has the daily precision you're looking for:

var today = new Date();
var tomorrow = new Date();
var yesterday = new Date();
tomorrow.setDate(today.getDate()+1);
yesterday.setDate(today.getDate()-1);

moment(today).from(moment(yesterday)); // "in a day"
moment(today).from(moment(tomorrow)); // "a day ago" 

moment(yesterday).from(moment(tomorrow)); // "2 days ago" 
moment(tomorrow).from(moment(yesterday)); // "in 2 days"

Build android release apk on Phonegap 3.x CLI

just wondered around a lot because I got the same issue but in my installation the command "cordova" was never available and "phone gap build android --release" just ignored the platform/android/ant.properties.

so looking inside my platform filter I found a folder named "cordova" and inside of it there was an "build" binary that accepted the --release argument, it asked me for the key chains and I ended with a signed and ready for production APK.

this was never documented in any part of the phone gap site and frankly speaking now I kinda hate phonegap :( it was supposed to make the things easier but everything was just complicated :(

Why does Git say my master branch is "already up to date" even though it is not?

Just a friendly reminder if you have files locally that aren't in github and yet your git status says

Your branch is up to date with 'origin/master'. nothing to commit, working tree clean

It can happen if the files are in .gitignore

Try running

cat .gitignore 

and seeing if these files show up there. That would explain why git doesn't want to move them to the remote.

JavaScript unit test tools for TDD

Karma or Protractor

Karma is a JavaScript test-runner built with Node.js and meant for unit testing.

The Protractor is for end-to-end testing and uses Selenium Web Driver to drive tests.

Both have been made by the Angular team. You can use any assertion-library you want with either.

Screencast: Karma Getting started

related:

pros:

  • Uses node.js, so compatible with Win/OS X/Linux
  • Run tests from a browser or headless with PhantomJS
  • Run on multiple clients at once
  • Option to launch, capture, and automatically shut down browsers
  • Option to run server/clients on development computer or separately
  • Run tests from a command line (can be integrated into ant/maven)
  • Write tests xUnit or BDD style
  • Supports multiple JavaScript test frameworks
  • Auto-run tests on save
  • Proxies requests cross-domain
  • Possible to customize:
    • Extend it to wrap other test-frameworks (Jasmine, Mocha, QUnit built-in)
    • Your own assertions/refutes
    • Reporters
    • Browser Launchers
  • Plugin for WebStorm
  • Supported by Netbeans IDE

Cons:

mocha.js

I'm totally unqualified to comment on mocha.js's features, strengths, and weaknesses, but it was just recommended to me by someone I trust in the JS community.

List of features, as reported by its website:

  • browser support
  • simple async support, including promises
  • test coverage reporting
  • string diff support
  • javascript # API for running tests
  • proper exit status for CI support etc
  • auto-detects and disables coloring for non-ttys
  • maps uncaught exceptions to the correct test case
  • async test timeout support
  • test-specific timeouts
  • growl notification support
  • reports test durations
  • highlights slow tests
  • file watcher support
  • global variable leak detection
  • optionally run tests that match a regexp
  • auto-exit to prevent "hanging" with an active loop
  • easily meta-generate suites & test-cases
  • mocha.opts file support
  • clickable suite titles to filter test execution
  • node debugger support
  • detects multiple calls to done()
  • use any assertion library you want
  • extensible reporting, bundled with 9+ reporters
  • extensible test DSLs or "interfaces"
  • before, after, before each, after each hook
  • arbitrary transpiler support (coffee-script etc)
  • TextMate bundle

yolpo

yolpo

This no longer exists, redirects to sequential.js instead

Yolpo is a tool to visualize the execution of javascript. Javascript API developers are encouraged to write their use cases to show and tell their API. Such use cases forms the basis of regression tests.

AVA

AVA logo

Futuristic test runner with built-in support for ES2015. Even though JavaScript is single-threaded, IO in Node.js can happen in parallel due to its async nature. AVA takes advantage of this and runs your tests concurrently, which is especially beneficial for IO heavy tests. In addition, test files are run in parallel as separate processes, giving you even better performance and an isolated environment for each test file.

  • Minimal and fast
  • Simple test syntax
  • Runs tests concurrently
  • Enforces writing atomic tests
  • No implicit globals
  • Isolated environment for each test file
  • Write your tests in ES2015
  • Promise support
  • Generator function support
  • Async function support
  • Observable support
  • Enhanced asserts
  • Optional TAP o utput
  • Clean stack traces

Buster.js

A JavaScript test-runner built with Node.js. Very modular and flexible. It comes with its own assertion library, but you can add your own if you like. The assertions library is decoupled, so you can also use it with other test-runners. Instead of using assert(!...) or expect(...).not..., it uses refute(...) which is a nice twist imho.

A browser JavaScript testing toolkit. It does browser testing with browser automation (think JsTestDriver), QUnit style static HTML page testing, testing in headless browsers (PhantomJS, jsdom, ...), and more. Take a look at the overview!

A Node.js testing toolkit. You get the same test case library, assertion library, etc. This is also great for hybrid browser and Node.js code. Write your test case with Buster.JS and run it both in Node.js and in a real browser.

Screencast: Buster.js Getting started (2:45)

pros:

  • Uses node.js, so compatible with Win/OS X/Linux
  • Run tests from a browser or headless with PhantomJS (soon)
  • Run on multiple clients at once
  • Supports NodeJS testing
  • Don't need to run server/clients on development computer (no need for IE)
  • Run tests from a command line (can be integrated into ant/maven)
  • Write tests xUnit or BDD style
  • Supports multiple JavaScript test frameworks
  • Defer tests instead of commenting them out
  • SinonJS built-in
  • Auto-run tests on save
  • Proxies requests cross-domain
  • Possible to customize:
    • Extend it to wrap other test-frameworks (JsTestDriver built in)
    • Your own assertions/refutes
    • Reporters (xUnit XML, traditional dots, specification, tap, TeamCity and more built-in)
    • Customize/replace the HTML that is used to run the browser-tests
  • TextMate and Emacs integration

Cons:

  • Stil in beta so can be buggy
  • No plugin for Eclipse/IntelliJ (yet)
  • Doesn't group results by os/browser/version like TestSwarm *. It does, however, print out the browser name and version in the test results.
  • No history of previous test results like TestSwarm *
  • Doesn't fully work on windows as of May 2014

* TestSwarm is also a Continuous Integration server, while you need a separate CI server for Buster.js. It does, however, output xUnit XML reports, so it should be easy to integrate with Hudson, Bamboo or other CI servers.

TestSwarm

https://github.com/jquery/testswarm

TestSwarm is officially no longer under active development as stated on their GitHub webpage. They recommend Karma, browserstack-runner, or Intern.

Jasmine

Jasmine

This is a behavior-driven framework (as stated in quote below) that might interest developers familiar with Ruby or Ruby on Rails. The syntax is based on RSpec that are used for testing in Rails projects.

Jasmine specs can be run from an html page (in qUnit fashion) or from a test runner (as Karma).

Jasmine is a behavior-driven development framework for testing your JavaScript code. It does not depend on any other JavaScript frameworks. It does not require a DOM.

If you have experience with this testing framework, please contribute with more info :)

Project home: http://jasmine.github.io/

QUnit

QUnit focuses on testing JavaScript in the browser while providing as much convenience to the developer as possible. Blurb from the site:

QUnit is a powerful, easy-to-use JavaScript unit test suite. It's used by the jQuery, jQuery UI, and jQuery Mobile projects and is capable of testing any generic JavaScript code

QUnit shares some history with TestSwarm (above):

QUnit was originally developed by John Resig as part of jQuery. In 2008 it got its own home, name and API documentation, allowing others to use it for their unit testing as well. At the time it still depended on jQuery. A rewrite in 2009 fixed that, now QUnit runs completely standalone. QUnit's assertion methods follow the CommonJS Unit Testing specification, which was to some degree influenced by QUnit.

Project home: http://qunitjs.com/

Sinon

Another great tool is sinon.js by Christian Johansen, the author of Test-Driven JavaScript Development. Best described by himself:

Standalone test spies, stubs and mocks for JavaScript. No dependencies works with any unit testing framework.

Intern

The Intern Web site provides a direct feature comparison to the other testing frameworks on this list. It offers more features out of the box than any other JavaScript-based testing system.

JEST

A new but yet very powerful testing framework. It allows snapshot based testing as well this increases the testing speed and creates a new dynamic in terms of testing

Check out one of their talks: https://www.youtube.com/watch?v=cAKYQpTC7MA

Better yet: Getting Started

Avoid "current URL string parser is deprecated" warning by setting useNewUrlParser to true

This works for me nicely:

mongoose.set("useNewUrlParser", true);
mongoose.set("useUnifiedTopology", true);
mongoose
  .connect(db) //Connection string defined in another file
  .then(() => console.log("Mongo Connected..."))
  .catch(() => console.log(err));

How to download image using requests

Following code snippet downloads a file.

The file is saved with its filename as in specified url.

import requests

url = "http://example.com/image.jpg"
filename = url.split("/")[-1]
r = requests.get(url, timeout=0.5)

if r.status_code == 200:
    with open(filename, 'wb') as f:
        f.write(r.content)

How to get the last element of a slice?

Bit less elegant but can also do:

sl[len(sl)-1: len(sl)]

How to match hyphens with Regular Expression?

use "\p{Pd}" without quotes to match any type of hyphen. The '-' character is just one type of hyphen which also happens to be a special character in Regex.

SQL Server IF NOT EXISTS Usage?

Have you verified that there is in fact a row where Staff_Id = @PersonID? What you've posted works fine in a test script, assuming the row exists. If you comment out the insert statement, then the error is raised.

set nocount on

create table Timesheet_Hours (Staff_Id int, BookedHours int, Posted_Flag bit)

insert into Timesheet_Hours (Staff_Id, BookedHours, Posted_Flag) values (1, 5.5, 0)

declare @PersonID int
set @PersonID = 1

IF EXISTS    
    (
    SELECT 1    
    FROM Timesheet_Hours    
    WHERE Posted_Flag = 1    
        AND Staff_Id = @PersonID    
    )    
    BEGIN
        RAISERROR('Timesheets have already been posted!', 16, 1)
        ROLLBACK TRAN
    END
ELSE
    IF NOT EXISTS
        (
        SELECT 1
        FROM Timesheet_Hours
        WHERE Staff_Id = @PersonID
        )
        BEGIN
            RAISERROR('Default list has not been loaded!', 16, 1)
            ROLLBACK TRAN
        END
    ELSE
        print 'No problems here'

drop table Timesheet_Hours

Best Java obfuscator?

I don't know for sure if the solution is safe, but about the ClassGuard solution, it's interesting to read the article and the comment at: http://www.javaworld.com/community/?q=node/1604#comment-12296

Should I use 'has_key()' or 'in' on Python dicts?

According to python docs:

has_key() is deprecated in favor of key in d.

Error inflating class android.support.design.widget.NavigationView

Following below steps will surely remove this error.

  • Find the widget causing the error.
  • Go the layout file where that widget is declared.
  • Check for all the resources (drawables etc.) used in that file.
  • Then make sure that resource is there in all versions of drawables (drawable-v21,drawable etc.)

Cheers!!

How to copy files from host to Docker container?

I tried most of the (upvoted) solutions here but in docker 17.09 (in 2018) there is no longer /var/lib/docker/aufs folder.

This simple docker cp solved this task.

docker cp c:\path\to\local\file container_name:/path/to/target/dir/

How to get container_name?

 docker ps 

There is a NAMES section. Don't use aIMAGE.

Purpose of #!/usr/bin/python3 shebang

Actually the determination of what type of file a file is very complicated, so now the operating system can't just know. It can make lots of guesses based on -

  • extension
  • UTI
  • MIME

But the command line doesn't bother with all that, because it runs on a limited backwards compatible layer, from when that fancy nonsense didn't mean anything. If you double click it sure, a modern OS can figure that out- but if you run it from a terminal then no, because the terminal doesn't care about your fancy OS specific file typing APIs.

Regarding the other points. It's a convenience, it's similarly possible to run

python3 path/to/your/script

If your python isn't in the path specified, then it won't work, but we tend to install things to make stuff like this work, not the other way around. It doesn't actually matter if you're under *nix, it's up to your shell whether to consider this line because it's a shellcode. So for example you can run bash under Windows.

You can actually ommit this line entirely, it just mean the caller will have to specify an interpreter. Also don't put your interpreters in nonstandard locations and then try to call scripts without providing an interpreter.

start MySQL server from command line on Mac OS Lion

On mac Big Sur and MySQL 5.7, I needed to stop/start with:

sudo launchctl load -F /Library/LaunchDaemons/com.oracle.oss.mysql.mysqld.plist

and

sudo launchctl unload -F /Library/LaunchDaemons/com.oracle.oss.mysql.mysqld.plist

This answer came from https://coolestguidesontheplanet.com/start-stop-mysql-from-the-command-line-terminal-osx-linux/

Focus Input Box On Load

If you can't add to the BODY tag for some reason, you can add this AFTER the Form:

<SCRIPT type="text/javascript">
    document.yourFormName.yourFieldName.focus();
</SCRIPT>

Comments in .gitignore?

Yes, you may put comments in there. They however must start at the beginning of a line.

cf. http://git-scm.com/book/en/Git-Basics-Recording-Changes-to-the-Repository#Ignoring-Files

The rules for the patterns you can put in the .gitignore file are as follows:
- Blank lines or lines starting with # are ignored.
[…]

The comment character is #, example:

# no .a files
*.a

Build .so file from .c file using gcc command line

To generate a shared library you need first to compile your C code with the -fPIC (position independent code) flag.

gcc -c -fPIC hello.c -o hello.o

This will generate an object file (.o), now you take it and create the .so file:

gcc hello.o -shared -o libhello.so

EDIT: Suggestions from the comments:

You can use

gcc -shared -o libhello.so -fPIC hello.c

to do it in one step. – Jonathan Leffler

I also suggest to add -Wall to get all warnings, and -g to get debugging information, to your gcc commands. – Basile Starynkevitch

Concatenate strings from several rows using Pandas groupby

For me the above solutions were close but added some unwanted /n's and dtype:object, so here's a modified version:

df.groupby(['name', 'month'])['text'].apply(lambda text: ''.join(text.to_string(index=False))).str.replace('(\\n)', '').reset_index()

How can I display just a portion of an image in HTML/CSS?

One way to do it is to set the image you want to display as a background in a container (td, div, span etc) and then adjust background-position to get the sprite you want.

Normalization in DOM parsing with java - how does it work?

In simple, Normalisation is Reduction of Redundancies.
Examples of Redundancies:
a) white spaces outside of the root/document tags(...<document></document>...)
b) white spaces within start tag (<...>) and end tag (</...>)
c) white spaces between attributes and their values (ie. spaces between key name and =")
d) superfluous namespace declarations
e) line breaks/white spaces in texts of attributes and tags
f) comments etc...

Windows batch command(s) to read first line from text file

Here's a general-purpose batch file to print the top n lines from a file like the GNU head utility, instead of just a single line.

@echo off

if [%1] == [] goto usage
if [%2] == [] goto usage

call :print_head %1 %2
goto :eof

REM
REM print_head
REM Prints the first non-blank %1 lines in the file %2.
REM
:print_head
setlocal EnableDelayedExpansion
set /a counter=0

for /f ^"usebackq^ eol^=^

^ delims^=^" %%a in (%2) do (
        if "!counter!"=="%1" goto :eof
        echo %%a
        set /a counter+=1
)

goto :eof

:usage
echo Usage: head.bat COUNT FILENAME

For example:

Z:\>head 1 "test file.c"
; this is line 1

Z:\>head 3 "test file.c"
; this is line 1
    this is line 2
line 3 right here

It does not currently count blank lines. It is also subject to the batch-file line-length restriction of 8 KB.

FutureWarning: elementwise comparison failed; returning scalar, but in the future will perform elementwise comparison

In my case, the warning occurred because of just the regular type of boolean indexing -- because the series had only np.nan. Demonstration (pandas 1.0.3):

>>> import pandas as pd
>>> import numpy as np
>>> pd.Series([np.nan, 'Hi']) == 'Hi'
0    False
1     True
>>> pd.Series([np.nan, np.nan]) == 'Hi'
~/anaconda3/envs/ms3/lib/python3.7/site-packages/pandas/core/ops/array_ops.py:255: FutureWarning: elementwise comparison failed; returning scalar instead, but in the future will perform elementwise comparison
  res_values = method(rvalues)
0    False
1    False

I think with pandas 1.0 they really want you to use the new 'string' datatype which allows for pd.NA values:

>>> pd.Series([pd.NA, pd.NA]) == 'Hi'
0    False
1    False
>>> pd.Series([np.nan, np.nan], dtype='string') == 'Hi'
0    <NA>
1    <NA>
>>> (pd.Series([np.nan, np.nan], dtype='string') == 'Hi').fillna(False)
0    False
1    False

Don't love at which point they tinkered with every-day functionality such as boolean indexing.

OAuth 2.0 Authorization Header

For those looking for an example of how to pass the OAuth2 authorization (access token) in the header (as opposed to using a request or body parameter), here is how it's done:

Authorization: Bearer 0b79bab50daca910b000d4f1a2b675d604257e42

Random "Element is no longer attached to the DOM" StaleElementReferenceException

In Java 8 you can use very simple method for that:

private Object retryUntilAttached(Supplier<Object> callable) {
    try {
        return callable.get();
    } catch (StaleElementReferenceException e) {
        log.warn("\tTrying once again");
        return retryUntilAttached(callable);
    }
}

How to load GIF image in Swift?

it would be great if somebody told to put gif into any folder instead of assets folder

Convert double to float in Java

Use dataType casting. For example:

// converting from double to float:
double someValue;
// cast someValue to float!
float newValue = (float)someValue;

Cheers!

Note:

Integers are whole numbers, e.g. 10, 400, or -5.

Floating point numbers (floats) have decimal points and decimal places, for example 12.5, and 56.7786543.

Doubles are a specific type of floating point number that have greater precision than standard floating point numbers (meaning that they are accurate to a greater number of decimal places).

How to run a Maven project from Eclipse?

(Alt + Shift + X) , then M to Run Maven Build. You will need to specify the Maven goals you want on Run -> Run Configurations

What is Linux’s native GUI API?

The closest thing to Win32 in linux would be the libc, as you mention not only the UI but events and "other os stuff"

How to rename files and folder in Amazon S3?

You can either use AWS CLI or s3cmd command to rename the files and folders in AWS S3 bucket.

Using S3cmd, use the following syntax to rename a folder,

s3cmd --recursive mv s3://<s3_bucketname>/<old_foldername>/ s3://<s3_bucketname>/<new_folder_name>

Using AWS CLI, use the following syntax to rename a folder,

aws s3 --recursive mv s3://<s3_bucketname>/<old_foldername>/ s3://<s3_bucketname>/<new_folder_name>

How can I extract substrings from a string in Perl?

You could use a regular expression such as the following:

/([-a-z0-9]+)\s*\((.*?)\)\s*(\*)?/

So for example:

$s = "abc-456-hu5t10 (High priority) *";
$s =~ /([-a-z0-9]+)\s*\((.*?)\)\s*(\*)?/;
print "$1\n$2\n$3\n";

prints

abc-456-hu5t10
High priority
*

How to run python script with elevated privilege on windows

in comments to the answer you took the code from someone says ShellExecuteEx doesn't post its STDOUT back to the originating shell. so you will not see "I am root now", even though the code is probably working fine.

instead of printing something, try writing to a file:

import os
import sys
import win32com.shell.shell as shell
ASADMIN = 'asadmin'

if sys.argv[-1] != ASADMIN:
    script = os.path.abspath(sys.argv[0])
    params = ' '.join([script] + sys.argv[1:] + [ASADMIN])
    shell.ShellExecuteEx(lpVerb='runas', lpFile=sys.executable, lpParameters=params)
    sys.exit(0)
with open("somefilename.txt", "w") as out:
    print >> out, "i am root"

and then look in the file.

Decoding a Base64 string in Java

The following should work with the latest version of Apache common codec

byte[] decodedBytes = Base64.getDecoder().decode("YWJjZGVmZw==");
System.out.println(new String(decodedBytes));

and for encoding

byte[] encodedBytes = Base64.getEncoder().encode(decodedBytes);
System.out.println(new String(encodedBytes));

ReactJS Two components communicating

Oddly nobody mentioned mobx. The idea is similar to redux. If I have a piece of data that multiple components are subscribed to it, then I can use this data to drive multiple components.

Open file by its full path in C++

Normally one uses the backslash character as the path separator in Windows. So:

ifstream file;
file.open("C:\\Demo.txt", ios::in);

Keep in mind that when written in C++ source code, you must use the double backslash because the backslash character itself means something special inside double quoted strings. So the above refers to the file C:\Demo.txt.

How to split a python string on new line characters

a.txt

this is line 1
this is line 2

code:

Python 3.4.0 (default, Mar 20 2014, 22:43:40) 
[GCC 4.6.3] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> file = open('a.txt').read()
>>> file
>>> file.split('\n')
['this is line 1', 'this is line 2', '']

I'm on Linux, but I guess you just use \r\n on Windows and it would also work

Updating a dataframe column in spark

While you cannot modify a column as such, you may operate on a column and return a new DataFrame reflecting that change. For that you'd first create a UserDefinedFunction implementing the operation to apply and then selectively apply that function to the targeted column only. In Python:

from pyspark.sql.functions import UserDefinedFunction
from pyspark.sql.types import StringType

name = 'target_column'
udf = UserDefinedFunction(lambda x: 'new_value', StringType())
new_df = old_df.select(*[udf(column).alias(name) if column == name else column for column in old_df.columns])

new_df now has the same schema as old_df (assuming that old_df.target_column was of type StringType as well) but all values in column target_column will be new_value.

How to detect orientation change in layout in Android?

for Kotilin implementation in the simplest form - only fires when screen changes from portrait <--> landscape if need device a flip detection (180 degree) you'll need to tab in to gravity sensor values

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

val rotation = windowManager.defaultDisplay.rotation

    when (rotation) {            
        0 -> Log.d(TAG,"at zero degree")
        1 -> Log.d(TAG,"at 270 degree")
        2 -> Log.d(TAG,"at 180 degree")
        3 -> Log.d(TAG,"at 90 degree")


    }
}

Removing space from dataframe columns in pandas

  • To remove white spaces:

1) To remove white space everywhere:

df.columns = df.columns.str.replace(' ', '')

2) To remove white space at the beginning of string:

df.columns = df.columns.str.lstrip()

3) To remove white space at the end of string:

df.columns = df.columns.str.rstrip()

4) To remove white space at both ends:

df.columns = df.columns.str.strip()
  • To replace white spaces with other characters (underscore for instance):

5) To replace white space everywhere

df.columns = df.columns.str.replace(' ', '_')

6) To replace white space at the beginning:

df.columns = df.columns.str.replace('^ +', '_')

7) To replace white space at the end:

df.columns = df.columns.str.replace(' +$', '_')

8) To replace white space at both ends:

df.columns = df.columns.str.replace('^ +| +$', '_')

All above applies to a specific column as well, assume you have a column named col, then just do:

df[col] = df[col].str.strip()  # or .replace as above

Java better way to delete file if exists

file.delete();

if the file doesn't exist, it will return false.

How to search file text for a pattern and replace it with a given value

If you need to do substitutions across line boundaries, then using ruby -pi -e won't work because the p processes one line at a time. Instead, I recommend the following, although it could fail with a multi-GB file:

ruby -e "file='translation.ja.yml'; IO.write(file, (IO.read(file).gsub(/\s+'$/, %q('))))"

The is looking for white space (potentially including new lines) following by a quote, in which case it gets rid of the whitespace. The %q(')is just a fancy way of quoting the quote character.

Can an AJAX response set a cookie?

According to the w3 spec section 4.6.3 for XMLHttpRequest a user agent should honor the Set-Cookie header. So the answer is yes you should be able to.

Quotation:

If the user agent supports HTTP State Management it should persist, discard and send cookies (as received in the Set-Cookie response header, and sent in the Cookie header) as applicable.

Sometimes adding a WCF Service Reference generates an empty reference.cs

I also had the issue of broken service references when working with project references on both sides (the service project and the project having a reference to the service). If the the .dll of the referenced project for example is called "Contoso.Development.Common", but the projects name is simply shortened to "Common", also project references to this project are named just "Common". The service however expects a reference to "Contoso.Development.Common" for resolving classes (if this option is activated in the service reference options).

So with explorer I opened the folder of the project which is referencing the service and the "Common"-project. There I editet the VS project file (.csproj) with notepad. Search for the name of the refernced project (which is "Common.csproj" in this example) and you will quickly find the configuration entry representing the project reference.

I changed

<ProjectReference Include="..\Common\Common.csproj"> <Project>{C90AAD45-6857-4F83-BD1D-4772ED50D44C}</Project> <Name>Common</Name> </ProjectReference>

to

<ProjectReference Include="..\Common\Common.csproj"> <Project>{C90AAD45-6857-4F83-BD1D-4772ED50D44C}</Project> <Name>Contoso.Development.Common</Name> </ProjectReference>

The important thing is to change the name of the reference to the name of the dll the referenced project has as output.

Then switch back to VS. There you will be asked to reload the project since it has been modified outside of VS. Click the reload button.

After doing so adding und updating the service reference worked just as expected.

Hope this also helps someone else.

Regards MH

Wrapping long text without white space inside of a div

white-space: pre-wrap

is what worked for me for <span> and <div>.

How do I shrink my SQL Server Database?

"Therefore it's reasonable to assume much space should now be retrievable."

Apologies if I misunderstood the question, but are you sure it's the database and not the log files that are using up the space? Check to see what recovery model the database is in. Chances are it's in Full, which means the log file is never truncated. If you don't need a complete record of every transaction, you should be able to change to Simple, which will truncate the logs. You can shrink the database during the process. Assuming things go right, the process looks like:

  1. Backup the database!
  2. Change to Simple Recovery
  3. Shrink db (right-click db, choose all tasks > shrink db -> set to 10% free space)
  4. Verify that the space has been reclaimed, if not you might have to do a full backup

If that doesn't work (or you get a message saying "log file is full" when you try to switch recovery modes), try this:

  1. Backup
  2. Kill all connections to the db
  3. Detach db (right-click > Detach or right-click > All Tasks > Detach)
  4. Delete the log (ldf) file
  5. Reattach the db
  6. Change the recovery mode

etc.

C# Macro definitions in Preprocessor

Turn the C Macro into a C# static method in a class.

How can I rebuild indexes and update stats in MySQL innoDB?

You can also use the provided CLI tool mysqlcheck to run the optimizations. It's got a ton of switches but at its most basic you just pass in the database, username, and password.

Adding this to cron or the Windows Scheduler can make this an automated process. (MariaDB but basically the same thing.)

How to get just the parent directory name of a specific file

File file = new File("C:/aaa/bbb/ccc/ddd/test.java");
File curentPath = new File(file.getParent());
//get current path "C:/aaa/bbb/ccc/ddd/"
String currentFolder= currentPath.getName().toString();
//get name of file to string "ddd"

if you need to append folder "ddd" by another path use;

String currentFolder= "/" + currentPath.getName().toString();

Explicitly set column value to null SQL Developer

It is clear that most people who haven't used SQL Server Enterprise Manager don't understand the question (i.e. Justin Cave).

I came upon this post when I wanted to know the same thing.

Using SQL Server, when you are editing your data through the MS SQL Server GUI Tools, you can use a KEYBOARD SHORTCUT to insert a NULL rather than having just an EMPTY CELL, as they aren't the same thing. An empty cell can have a space in it, rather than being NULL, even if it is technically empty. The difference is when you intentionally WANT to put a NULL in a cell rather than a SPACE or to empty it and NOT using a SQL statement to do so.

So, the question really is, how do I put a NULL value in the cell INSTEAD of a space to empty the cell?

I think the answer is, that the way the Oracle Developer GUI works, is as Laniel indicated above, And THAT should be marked as the answer to this question.

Oracle Developer seems to default to NULL when you empty a cell the way the op is describing it.

Additionally, you can force Oracle Developer to change how your null cells look by changing the color of the background color to further demonstrate when a cell holds a null:

Tools->Preferences->Advanced->Display Null Using Background Color

or even the VALUE it shows when it's null:

Tools->Preferences->Advanced->Display Null Value As

Hope that helps in your transition.

What is the difference between \r and \n?

They're different characters. \r is carriage return, and \n is line feed.

On "old" printers, \r sent the print head back to the start of the line, and \n advanced the paper by one line. Both were therefore necessary to start printing on the next line.

Obviously that's somewhat irrelevant now, although depending on the console you may still be able to use \r to move to the start of the line and overwrite the existing text.

More importantly, Unix tends to use \n as a line separator; Windows tends to use \r\n as a line separator and Macs (up to OS 9) used to use \r as the line separator. (Mac OS X is Unix-y, so uses \n instead; there may be some compatibility situations where \r is used instead though.)

For more information, see the Wikipedia newline article.

EDIT: This is language-sensitive. In C# and Java, for example, \n always means Unicode U+000A, which is defined as line feed. In C and C++ the water is somewhat muddier, as the meaning is platform-specific. See comments for details.