Programs & Examples On #Service factory

How to list all the files in android phone by using adb shell?

just to add the full command:

adb shell ls -R | grep filename

this is actually a pretty fast lookup on Android

Different ways of adding to Dictionary

Given the, most than probable similarities in performance, use whatever feel more correct and readable to the piece of code you're using.

I feel an operation that describes an addition, being the presence of the key already a really rare exception is best represented with the add. Semantically it makes more sense.

The dict[key] = value represents better a substitution. If I see that code I half expect the key to already be in the dictionary anyway.

How to create EditText with rounded corners?

If you want only corner should curve not whole end, then use below code.

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" >

    <corners android:radius="10dp" />

    <padding
        android:bottom="3dp"
        android:left="0dp"
        android:right="0dp"
        android:top="3dp" />

    <gradient
        android:angle="90"
        android:endColor="@color/White"
        android:startColor="@color/White" />

    <stroke
        android:width="1dp"
        android:color="@color/Gray" />

</shape>

It will only curve the four angle of EditText.

react native get TextInput value

There is huge difference between onChange and onTextChange prop of <TextInput />. Don't be like me and use onTextChange which returns string and don't use onChange which returns full objects.

I feel dumb for spending like 1 hour figuring out where is my value.

How to convert InputStream to FileInputStream

You need something like:

    URL resource = this.getClass().getResource("/path/to/resource.res");
    File is = null;
    try {
        is = new File(resource.toURI());
    } catch (URISyntaxException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }
    try {
        FileInputStream input = new FileInputStream(is);
    } catch (FileNotFoundException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }

But it will work only within your IDE, not in runnable JAR. I had same problem explained here.

Python float to int conversion

int converts by truncation, as has been mentioned by others. This can result in the answer being one different than expected. One way around this is to check if the result is 'close enough' to an integer and adjust accordingly, otherwise the usual conversion. This is assuming you don't get too much roundoff and calculation error, which is a separate issue. For example:

def toint(f):
    trunc = int(f)
    diff = f - trunc

    # trunc is one too low
    if abs(f - trunc - 1) < 0.00001:
        return trunc + 1
    # trunc is one too high
    if abs(f - trunc + 1) < 0.00001:
        return trunc - 1
    # trunc is the right value
    return trunc

This function will adjust for off-by-one errors for near integers. The mpmath library does something similar for floating point numbers that are close to integers.

MYSQL Sum Query with IF Condition

Try with a CASE in this way :

SUM(CASE 
    WHEN PaymentType = "credit card" 
    THEN TotalAmount 
    ELSE 0 
END) AS CreditCardTotal,

Should give what you are looking for ...

Fixed positioned div within a relative parent div

An easy solution that doesn't involve resorting to JavaScript and will not break CSS transforms is to simply have a non-scrolling element, the same size as your scrolling element, absolute-positioned over it.

The basic HTML structure would be

CSS

<style>
    .parent-to-position-by {
        position: relative;
        top: 40px; /* just to show it's relative positioned */
    }
    .scrolling-contents {
        display: inline-block;
        width: 100%;
        height: 200px;
        line-height: 20px;
        white-space: nowrap;
        background-color: #CCC;
        overflow: scroll;
    }
    .fixed-elements {
        display: inline-block;
        position: absolute;
        top: 0;
        left: 0;
    }
    .fixed {
        position: absolute; /* effectively fixed */
        top: 20px;
        left: 20px;
        background-color: #F00;
        width: 200px;
        height: 20px;
    }
</style>

HTML

<div class="parent-to-position-by">
    <div class="fixed-elements">
        <div class="fixed">
            I am &quot;fixed positioned&quot;
        </div>
    </div>
    <div class="scrolling-contents">
        Lots of contents which may be scrolled.
    </div>
</div>
  • parent-to-position-by would be the relative div to position something fixed with respect to.
  • scrolling-contents would span the size of this div and contain its main contents
  • fixed-elements is just an absolute-positioned div spanning the same space over top of the scrolling-contents div.
  • by absolute-positioning the div with the fixed class, it achieves the same effect as if it were fixed-positioned with respect to the parent div. (or the scrolling contents, as they span that full space)

Here's a js-fiddle with a working example

Fill username and password using selenium in python

from selenium import webdriver
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.support.ui import Select
from selenium.webdriver.support.ui import WebDriverWait

# If you want to open Chrome
driver = webdriver.Chrome()
# If you want to open Firefox
driver = webdriver.Firefox()

username = driver.find_element_by_id("username")
password = driver.find_element_by_id("password")
username.send_keys("YourUsername")
password.send_keys("YourPassword")
driver.find_element_by_id("submit_btn").click()

Simplest way to do a recursive self-join?

The Quassnoi query with a change for large table. Parents with more childs then 10: Formating as str(5) the row_number()

WITH    q AS 
        (
        SELECT  m.*, CAST(str(ROW_NUMBER() OVER (ORDER BY m.ordernum),5) AS VARCHAR(MAX)) COLLATE Latin1_General_BIN AS bc
        FROM    #t m
        WHERE   ParentID =0
        UNION ALL
        SELECT  m.*,  q.bc + '.' + str(ROW_NUMBER()  OVER (PARTITION BY m.ParentID ORDER BY m.ordernum),5) COLLATE Latin1_General_BIN
        FROM    #t m
        JOIN    q
        ON      m.parentID = q.DBID
        )
SELECT  *
FROM    q
ORDER BY
        bc

Django 1.7 - "No migrations to apply" when run migrate after makemigrations

@phanhuy152 has the best answer. Just to add my two cents:

His solution is:

  1. Delete migration history in DB
  2. Delete migrations folder
  3. Edit your model to be consistent with DB before your change
  4. makemigrations to restore the initial state of the migration files
  5. Then, change the model as you like
  6. makemigrations again
  7. migrate to apply updates to table.

But in my case, I have several models in the models.py file and at the last step, Django complains about Table xxx already exists, because the initial migrations files intends to create the xxx table again, when we just don't (and don't want to)drop other tables.

In this case, in order to preserve the data, we must tell Django to leave them alone in migrate. We just do: (assume that class A is the one we change, and class B, C remain same):

models.py:

from django.db import models

class A(models.Models):
    ...

class B(models.Models):
    class Meta:
        managed = False   # tell Django to leave this class alone

    ...

class C(models.Models):
    class Meta:
        managed = False   # tell Django to leave this class alone

Add these lines after we construct the initial migrations.

So, the process now is:

  1. ...
  2. ...
  3. ...
  4. ...
  5. Add managed = False to other classes
  6. makemigrations to apply Meta changes. You will see something like:

output:

Migrations for 'backEnd':
  backEnd/migrations/0002_auto_20180412_1654.py
    - Change Meta options on toid
    - Change Meta options on tprocessasinc
    - Change Meta options on tservers
    - Change Meta options on tsnmpserver
  1. migrate to apply them in DB
  2. Change your model now: add a field, change the type, etc.
  3. migrate again.
  4. Delete the Meta class to let Django manage other class again. makemigrations, migrate again.

Now you have all the structure and data of your models, without losing the part formerly stored in DB.

Why an inline "background-image" style doesn't work in Chrome 10 and Internet Explorer 8?

As c-smile mentioned: Just need to remove the apostrophes in the url():

<div style="background-image: url(http://i54.tinypic.com/4zuxif.jpg)"></div>

Demo here

Retrieve specific commit from a remote Git repository

You can simply fetch the remote repo with:

git fetch <repo>

where,

  • <repo> can be a remote repo name (e.g. origin) or even a remote repo URL (e.g. https://git.foo.com/myrepo.git)

for example:

git fetch https://git.foo.com/myrepo.git 

after you fetched the repos you may merge the commits that you want (since the question is about retrieve one commit, instead merge you may use cherry-pick to pick just one commit):

git merge <commit>
  • <commit> can be the SHA1 commit

for example:

git cherry-pick 0a071603d87e0b89738599c160583a19a6d95545

or

git merge 0a071603d87e0b89738599c160583a19a6d95545

if is the latest commit that you want to merge, you also may use FETCH_HEAD variable :

git cherry-pick (or merge) FETCH_HEAD

Why do I need to do `--set-upstream` all the time?

Here is a bash alias for git push which is safe to run for every push and will automatically switch between setting upstream for the first push and then doing normal pushes after that.

alias gpu='[[ -z $(git config "branch.$(git symbolic-ref --short HEAD).merge") ]] && git push -u origin $(git symbolic-ref --short HEAD) || git push'

Original Post

how to upload a file to my server using html

You need enctype="multipart/form-data" otherwise you will load only the file name and not the data.

Python List & for-each access (Find/Replace in built-in list)

Answering this has been good, as the comments have led to an improvement in my own understanding of Python variables.

As noted in the comments, when you loop over a list with something like for member in my_list the member variable is bound to each successive list element. However, re-assigning that variable within the loop doesn't directly affect the list itself. For example, this code won't change the list:

my_list = [1,2,3]
for member in my_list:
    member = 42
print my_list

Output:

[1, 2, 3]

If you want to change a list containing immutable types, you need to do something like:

my_list = [1,2,3]
for ndx, member in enumerate(my_list):
    my_list[ndx] += 42
print my_list

Output:

[43, 44, 45]

If your list contains mutable objects, you can modify the current member object directly:

class C:
    def __init__(self, n):
        self.num = n
    def __repr__(self):
        return str(self.num)

my_list = [C(i) for i in xrange(3)]
for member in my_list:
    member.num += 42
print my_list

[42, 43, 44]

Note that you are still not changing the list, simply modifying the objects in the list.

You might benefit from reading Naming and Binding.

jquery clone div and append it after specific div

try this out

$("div[id^='car']:last").after($('#car2').clone());

How to open some ports on Ubuntu?

Ubuntu these days comes with ufw - Uncomplicated Firewall. ufw is an easy-to-use method of handling iptables rules.

Try using this command to allow a port

sudo ufw allow 1701

To test connectivity, you could try shutting down the VPN software (freeing up the ports) and using netcat to listen, like this:

nc -l 1701

Then use telnet from your Windows host and see what shows up on your Ubuntu terminal. This can be repeated for each port you'd like to test.

Pointer to 2D arrays in C

//defines an array of 280 pointers (1120 or 2240 bytes)
int  *pointer1 [280];

//defines a pointer (4 or 8 bytes depending on 32/64 bits platform)
int (*pointer2)[280];      //pointer to an array of 280 integers
int (*pointer3)[100][280]; //pointer to an 2D array of 100*280 integers

Using pointer2 or pointer3 produce the same binary except manipulations as ++pointer2 as pointed out by WhozCraig.

I recommend using typedef (producing same binary code as above pointer3)

typedef int myType[100][280];
myType *pointer3;

Note: Since C++11, you can also use keyword using instead of typedef

using myType = int[100][280];
myType *pointer3;

in your example:

myType *pointer;                // pointer creation
pointer = &tab1;                // assignation
(*pointer)[5][12] = 517;        // set (write)
int myint = (*pointer)[5][12];  // get (read)

Note: If the array tab1 is used within a function body => this array will be placed within the call stack memory. But the stack size is limited. Using arrays bigger than the free memory stack produces a stack overflow crash.

The full snippet is online-compilable at gcc.godbolt.org

int main()
{
    //defines an array of 280 pointers (1120 or 2240 bytes)
    int  *pointer1 [280];
    static_assert( sizeof(pointer1) == 2240, "" );

    //defines a pointer (4 or 8 bytes depending on 32/64 bits platform)
    int (*pointer2)[280];      //pointer to an array of 280 integers
    int (*pointer3)[100][280]; //pointer to an 2D array of 100*280 integers  
    static_assert( sizeof(pointer2) == 8, "" );
    static_assert( sizeof(pointer3) == 8, "" );

    // Use 'typedef' (or 'using' if you use a modern C++ compiler)
    typedef int myType[100][280];
    //using myType = int[100][280];

    int tab1[100][280];

    myType *pointer;                // pointer creation
    pointer = &tab1;                // assignation
    (*pointer)[5][12] = 517;        // set (write)
    int myint = (*pointer)[5][12];  // get (read)

    return myint;
}

Import SQL file into mysql

from the command line (cmd.exe, not from within mysql shell) try something like:

type c:/nite.sql | mysql -uuser -ppassword dbname

How do you build a Singleton in Dart?

As I'm not very fond of using the new keyword or other constructor like calls on singletons, I would prefer to use a static getter called inst for example:

// the singleton class
class Dao {
    // singleton boilerplate
        Dao._internal() {}
        static final Dao _singleton = new Dao._internal();
        static get inst => _singleton;

    // business logic
        void greet() => print("Hello from singleton");
}

example usage:

Dao.inst.greet();       // call a method

// Dao x = new Dao();   // compiler error: Method not found: 'Dao'

// verify that there only exists one and only one instance
assert(identical(Dao.inst, Dao.inst));

Sort a list of Class Instances Python

import operator
sorted_x = sorted(x, key=operator.attrgetter('score'))

if you want to sort x in-place, you can also:

x.sort(key=operator.attrgetter('score'))

Open Sublime Text from Terminal in macOS

I'm using oh-my-zsh on Mac OSX Mavericks and the symbol link didn't work for me, so I added an alias in my .zshrc file instead:

alias subl="/Applications/Sublime\ Text.app/Contents/SharedSupport/bin/subl"

Open a new terminal and you should be good to go, and type subl.

Executing periodic actions in Python

This will insert a 10 second sleep in between every call to foo(), which is approximately what you asked for should the call complete quickly.

import time

while True:
    foo()
    time.sleep(10)

To do other things while your foo() is being called in a background thread

import time
import sys
import threading

def foo():
    sys.stdout.write('({}) foo\n'.format(time.ctime()))

def foo_target():
    while True:
        foo()
        time.sleep(10)

t = threading.Thread(target=foo_target)
t.daemon = True
t.start()
print('doing other things...')

How to use Sublime over SSH

You can try something that I've been working on called 'xeno'. It will allow you to open up files/folders in Sublime Text (or any local editor really) over an SSH connection and automatically synchronize changes to the remote machine. It should work on almost all POSIX systems (I myself use it from OS X to connect to Linux machines and edit files in Sublime Text). It's free and open source. I'd love some feedback.

For more information: it's basically a Git/SSH mashup written in Python that allows you to edit files and folders on a remote machine in a local editor. You don't have to configure kernel modules, you don't need to have a persistent connection, it's all automatic, and it won't interfere with existing source control because it uses an out-of-worktree Git repository. Also, because it's built on Git, it's extremely fast and supports automatic merging of files that might be changing on both ends, unlike SSHFS/SFTP which will just clobber any files with older timestamps.

How do you change the datatype of a column in SQL Server?

ALTER TABLE [dbo].[TableName]
ALTER COLUMN ColumnName VARCHAR(Max) NULL

.htaccess rewrite to redirect root URL to subdirectory

To set an invisible redirect from root to subfolder, You can use the following RewriteRule in /root/.htaccess :

RewriteEngine on

RewriteCond %{REQUEST_URI} !^/subfolder
RewriteRule ^(.*)$ /subfolder/$1 [NC,L]

The rule above will internally redirect the browser from :

to

And

to

while the browser will stay on the root folder.

How to edit the size of the submit button on a form?

You can change height and width with css:

#search {
     height: 100px;
     width: 400px;
}

It's worth pointing out that safari on OSX ignores most input button styles, however.

fill an array in C#

public static void Fill<T>(this IList<T> col, T value, int fromIndex, int toIndex)
{
    if (fromIndex > toIndex)
        throw new ArgumentOutOfRangeException("fromIndex");

    for (var i = fromIndex; i <= toIndex; i++)
        col[i] = value;
}

Something that works for all IList<T>s.

When do you use varargs in Java?

I have a varargs-related fear, too:

If the caller passes in an explicit array to the method (as opposed to multiple parameters), you will receive a shared reference to that array.

If you need to store this array internally, you might want to clone it first to avoid the caller being able to change it later.

 Object[] args = new Object[] { 1, 2, 3} ;

 varArgMethod(args);  // not varArgMethod(1,2,3);

 args[2] = "something else";  // this could have unexpected side-effects

While this is not really different from passing in any kind of object whose state might change later, since the array is usually (in case of a call with multiple arguments instead of an array) a fresh one created by the compiler internally that you can safely use, this is certainly unexpected behaviour.

iOS Swift - Get the Current Local Time and Date Timestamp

If you code for iOS 13.0 or later and want a timestamp, then you can use:

let currentDate = NSDate.now

Default Xmxsize in Java 8 (max heap size)

Like you have mentioned, The default -Xmxsize (Maximum HeapSize) depends on your system configuration.

Java8 client takes Larger of 1/64th of your physical memory for your Xmssize (Minimum HeapSize) and Smaller of 1/4th of your physical memory for your -Xmxsize (Maximum HeapSize).

Which means if you have a physical memory of 8GB RAM, you will have Xmssize as Larger of 8*(1/6) and Smaller of -Xmxsizeas 8*(1/4).

You can Check your default HeapSize with

In Windows:

java -XX:+PrintFlagsFinal -version | findstr /i "HeapSize PermSize ThreadStackSize"

In Linux:

java -XX:+PrintFlagsFinal -version | grep -iE 'HeapSize|PermSize|ThreadStackSize'

These default values can also be overrided to your desired amount.

Java client certificates over HTTPS/SSL

Have you set the KeyStore and/or TrustStore System properties?

java -Djavax.net.ssl.keyStore=pathToKeystore -Djavax.net.ssl.keyStorePassword=123456

or from with the code

System.setProperty("javax.net.ssl.keyStore", pathToKeyStore);

Same with javax.net.ssl.trustStore

How to do date/time comparison

For comparison between two times use time.Sub()

// utc life
loc, _ := time.LoadLocation("UTC")

// setup a start and end time
createdAt := time.Now().In(loc).Add(1 * time.Hour)
expiresAt := time.Now().In(loc).Add(4 * time.Hour)

// get the diff
diff := expiresAt.Sub(createdAt)
fmt.Printf("Lifespan is %+v", diff)

The program outputs:

Lifespan is 3h0m0s

http://play.golang.org/p/bbxeTtd4L6

Vertically align text to top within a UILabel

This code helps you to make the text aligned to top and also to make the label height to be fixed the text content.

instruction to use the below code

isHeightToChange by default it is true makes the height of label to same as text content automatically. isHeightToChange if it false make the text aligned to top with out decreasing the height of the label.

#import "DynamicHeightLable.h"

@implementation DynamicHeightLable
@synthesize isHeightToChange;
- (id)initWithFrame:(CGRect)frame 
{
    self = [super initWithFrame:frame];
    if (self)
    {
        // Initialization code.
        self.isHeightToChange=FALSE;//default

    }
    return self;
}
- (void)drawTextInRect:(CGRect)rect
{
    if(!isHeightToChange){
    CGSize maximumLabelSize = CGSizeMake(self.frame.size.width,2500);

    CGFloat height = [self.text sizeWithFont:self.font
                           constrainedToSize:maximumLabelSize
                               lineBreakMode:self.lineBreakMode].height;
    if (self.numberOfLines != 0) {
        height = MIN(height, self.font.lineHeight * self.numberOfLines);
    }
    rect.size.height = MIN(rect.size.height, height);
    }
    [super drawTextInRect:rect];

}
- (void) layoutSubviews
{
    [super layoutSubviews];
       if(isHeightToChange){
     CGRect ltempFrame = self.frame;
    CGSize maximumLabelSize = CGSizeMake(self.frame.size.width,2500);

    CGFloat height = [self.text sizeWithFont:self.font
                           constrainedToSize:maximumLabelSize
                               lineBreakMode:self.lineBreakMode].height;
    if (self.numberOfLines != 0) {
        height = MIN(height, self.font.lineHeight * self.numberOfLines);
    }
    ltempFrame.size.height = MIN(ltempFrame.size.height, height);

    ltempFrame.size.height=ltempFrame.size.height;
    self.frame=ltempFrame;
       }
}
@end

Data structure for maintaining tabular data in memory?

Having a "table" in memory that needs lookups, sorting, and arbitrary aggregation really does call out for SQL. You said you tried SQLite, but did you realize that SQLite can use an in-memory-only database?

connection = sqlite3.connect(':memory:')

Then you can create/drop/query/update tables in memory with all the functionality of SQLite and no files left over when you're done. And as of Python 2.5, sqlite3 is in the standard library, so it's not really "overkill" IMO.

Here is a sample of how one might create and populate the database:

import csv
import sqlite3

db = sqlite3.connect(':memory:')

def init_db(cur):
    cur.execute('''CREATE TABLE foo (
        Row INTEGER,
        Name TEXT,
        Year INTEGER,
        Priority INTEGER)''')

def populate_db(cur, csv_fp):
    rdr = csv.reader(csv_fp)
    cur.executemany('''
        INSERT INTO foo (Row, Name, Year, Priority)
        VALUES (?,?,?,?)''', rdr)

cur = db.cursor()
init_db(cur)
populate_db(cur, open('my_csv_input_file.csv'))
db.commit()

If you'd really prefer not to use SQL, you should probably use a list of dictionaries:

lod = [ ] # "list of dicts"

def populate_lod(lod, csv_fp):
    rdr = csv.DictReader(csv_fp, ['Row', 'Name', 'Year', 'Priority'])
    lod.extend(rdr)

def query_lod(lod, filter=None, sort_keys=None):
    if filter is not None:
        lod = (r for r in lod if filter(r))
    if sort_keys is not None:
        lod = sorted(lod, key=lambda r:[r[k] for k in sort_keys])
    else:
        lod = list(lod)
    return lod

def lookup_lod(lod, **kw):
    for row in lod:
        for k,v in kw.iteritems():
            if row[k] != str(v): break
        else:
            return row
    return None

Testing then yields:

>>> lod = []
>>> populate_lod(lod, csv_fp)
>>> 
>>> pprint(lookup_lod(lod, Row=1))
{'Name': 'Cat', 'Priority': '1', 'Row': '1', 'Year': '1998'}
>>> pprint(lookup_lod(lod, Name='Aardvark'))
{'Name': 'Aardvark', 'Priority': '1', 'Row': '4', 'Year': '2000'}
>>> pprint(query_lod(lod, sort_keys=('Priority', 'Year')))
[{'Name': 'Cat', 'Priority': '1', 'Row': '1', 'Year': '1998'},
 {'Name': 'Dog', 'Priority': '1', 'Row': '3', 'Year': '1999'},
 {'Name': 'Aardvark', 'Priority': '1', 'Row': '4', 'Year': '2000'},
 {'Name': 'Wallaby', 'Priority': '1', 'Row': '5', 'Year': '2000'},
 {'Name': 'Fish', 'Priority': '2', 'Row': '2', 'Year': '1998'},
 {'Name': 'Zebra', 'Priority': '3', 'Row': '6', 'Year': '2001'}]
>>> pprint(query_lod(lod, sort_keys=('Year', 'Priority')))
[{'Name': 'Cat', 'Priority': '1', 'Row': '1', 'Year': '1998'},
 {'Name': 'Fish', 'Priority': '2', 'Row': '2', 'Year': '1998'},
 {'Name': 'Dog', 'Priority': '1', 'Row': '3', 'Year': '1999'},
 {'Name': 'Aardvark', 'Priority': '1', 'Row': '4', 'Year': '2000'},
 {'Name': 'Wallaby', 'Priority': '1', 'Row': '5', 'Year': '2000'},
 {'Name': 'Zebra', 'Priority': '3', 'Row': '6', 'Year': '2001'}]
>>> print len(query_lod(lod, lambda r:1997 <= int(r['Year']) <= 2002))
6
>>> print len(query_lod(lod, lambda r:int(r['Year'])==1998 and int(r['Priority']) > 2))
0

Personally I like the SQLite version better since it preserves your types better (without extra conversion code in Python) and easily grows to accommodate future requirements. But then again, I'm quite comfortable with SQL, so YMMV.

What is the default database path for MongoDB?

The default dbpath for mongodb is /data/db.

There is no default config file, so you will either need to specify this when starting mongod with:

 mongod --config /etc/mongodb.conf

.. or use a packaged install of MongoDB (such as for Redhat or Debian/Ubuntu) which will include a config file path in the service definition.

Note: to check the dbpath and command-line options for a running mongod, connect via the mongo shell and run:

db.serverCmdLineOpts()

In particular, if a custom dbpath is set it will be the value of:

db.serverCmdLineOpts().parsed.dbpath           // MongoDB 2.4 and older
db.serverCmdLineOpts().parsed.storage.dbPath   // MongoDB 2.6+

NodeJS w/Express Error: Cannot GET /

I was facing the same problem as mentioned in the question. The following steps solved my problem.

I upgraded the nodejs package link with following steps

  1. Clear NPM's cache:

    npm cache clean -f
    
  2. Install a little helper called 'n'

    npm install -g n  
    

Then I went to node.js website, downloaded the latest node js package, installed it, and my problem was solved.

C# guid and SQL uniqueidentifier

// Create Instance of Connection and Command Object
SqlConnection myConnection = new SqlConnection(GentEFONRFFConnection);
myConnection.Open();
SqlCommand myCommand = new SqlCommand("your Procedure Name", myConnection);
myCommand.CommandType = CommandType.StoredProcedure;
myCommand.Parameters.Add("@orgid", SqlDbType.UniqueIdentifier).Value = orgid;
myCommand.Parameters.Add("@statid", SqlDbType.UniqueIdentifier).Value = statid;
myCommand.Parameters.Add("@read", SqlDbType.Bit).Value = read;
myCommand.Parameters.Add("@write", SqlDbType.Bit).Value = write;
// Mark the Command as a SPROC

myCommand.ExecuteNonQuery();

myCommand.Dispose();
myConnection.Close();

Android: Use a SWITCH statement with setOnClickListener/onClick for more than 1 button?

Another option is to add a new OnClickListener as parameter in setOnClickListener() and overriding the onClick()-method:

mycards_button = ((Button)this.findViewById(R.id.Button_MyCards)); 
exit_button = ((Button)this.findViewById(R.id.Button_Exit));

// Add onClickListener to mycards_button
mycards_button.setOnClickListener(new OnClickListener() {
    public void onClick(View view) {
        // Start new activity
        Intent intent = new Intent(this, MyCards.class);
        this.startActivity(intent);
    }
});

// Add onClickListener to exit_button
exit_button.setOnClickListener(new OnClickListener() {
    public void onClick(View view) {
        // Display alertDialog
        MyAlertDialog();
    }
});

Subset a dataframe by multiple factor levels

Try this:

> data[match(as.character(data$Code), selected, nomatch = FALSE), ]
    Code Value
1      A     1
2      B     2
1.1    A     1
1.2    A     1

Has anyone ever got a remote JMX JConsole to work?

I am running JConsole/JVisualVm on windows hooking to tomcat running Linux Redhat ES3.

Disabling packet filtering using the following command did the trick for me:

/usr/sbin/iptables -I INPUT -s jconsole-host -p tcp --destination-port jmxremote-port -j ACCEPT

where jconsole-host is either the hostname or the host address on which JConsole runs on and jmxremote-port is the port number set for com.sun.management.jmxremote.port for remote management.

What is a good practice to check if an environmental variable exists or not?

I'd recommend the following solution.

It prints the env vars you didn't include, which lets you add them all at once. If you go for the for loop, you're going to have to rerun the program to see each missing var.

from os import environ

REQUIRED_ENV_VARS = {"A", "B", "C", "D"}
diff = REQUIRED_ENV_VARS.difference(environ)
if len(diff) > 0:
    raise EnvironmentError(f'Failed because {diff} are not set')

Corrupted Access .accdb file: "Unrecognized Database Format"

Well, I have tried something I hope it helps ..

They changed the schema a little bit ..

Use the following :

1- Change the AccessDataSource to SQLDataSource in the toolbox.

2- In the drop down menu choose your access database (xxxx.accdb or xxxx.mdb)

3- Next -> Next -> Test Query -> Finish.

Worked for me.

How to easily get network path to the file you are working on?

Here's how to get the filepath of the file in Excel 2010.

1) Right click on the Ribbon.
2) Click on "Customize the Ribbon"
3) On the right hand side, click "New Group." This will add a new tab to the Ribbon. If you want to, click on the "Rename" button the right side and name your tab. For example, I named the tab "Doc Path." This step is optional
4) Under "Choose Commands From" on the left hand side, choose "Commands Not in the Ribbon."
5) Select "Document Location" and "Add" it to your newly created group.
6) The filepath should now appear under the newly created tab on the ribbon.

Android Calling JavaScript functions in WebView

Modification of @Ilya_Gazman answer

    private void callJavaScript(WebView view, String methodName, Object...params){
        StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append("javascript:try{");
        stringBuilder.append(methodName);
        stringBuilder.append("(");
        String separator = "";
        for (Object param : params) {               
            stringBuilder.append(separator);
            separator = ",";
            if(param instanceof String){
                stringBuilder.append("'");
            }
                stringBuilder.append(param.toString().replace("'", "\\'"));
            if(param instanceof String){
                stringBuilder.append("'");
            }

        }
        stringBuilder.append(")}catch(error){console.error(error.message);}");
        final String call = stringBuilder.toString();
        Log.i(TAG, "callJavaScript: call="+call);


        view.loadUrl(call);
    }

will correctly create JS calls e.g.

callJavaScript(mBrowser, "alert", "abc", "def");
//javascript:try{alert('abc','def')}catch(error){console.error(error.message);}
callJavaScript(mBrowser, "alert", 1, true, "abc");
//javascript:try{alert(1,true,'abc')}catch(error){console.error(error.message);}

Note that objects will not be passed correctly - but you can serialize them before passing as an argument.

Also I've changed where the error goes, I've diverted it to the console log which can be listened by:

    webView.setWebChromeClient(new CustomWebChromeClient());

and client

class CustomWebChromeClient extends WebChromeClient {
    private static final String TAG = "CustomWebChromeClient";

    @Override
    public boolean onConsoleMessage(ConsoleMessage cm) {
        Log.d(TAG, String.format("%s @ %d: %s", cm.message(),
                cm.lineNumber(), cm.sourceId()));
        return true;
    }
}

How can I recognize touch events using jQuery in Safari for iPad? Is it possible?

Using touchstart or touchend alone is not a good solution, because if you scroll the page, the device detects it as touch or tap too. So, the best way to detect a tap and click event at the same time is to just detect the touch events which are not moving the screen (scrolling). So to do this, just add this code to your application:

$(document).on('touchstart', function() {
    detectTap = true; // Detects all touch events
});
$(document).on('touchmove', function() {
    detectTap = false; // Excludes the scroll events from touch events
});
$(document).on('click touchend', function(event) {
    if (event.type == "click") detectTap = true; // Detects click events
       if (detectTap){
          // Here you can write the function or codes you want to execute on tap

       }
 });

I tested it and it works fine for me on iPad and iPhone. It detects tap and can distinguish tap and touch scroll easily.

Count number of rows by group using dplyr

There's a special function n() in dplyr to count rows (potentially within groups):

library(dplyr)
mtcars %>% 
  group_by(cyl, gear) %>% 
  summarise(n = n())
#Source: local data frame [8 x 3]
#Groups: cyl [?]
#
#    cyl  gear     n
#  (dbl) (dbl) (int)
#1     4     3     1
#2     4     4     8
#3     4     5     2
#4     6     3     2
#5     6     4     4
#6     6     5     1
#7     8     3    12
#8     8     5     2

But dplyr also offers a handy count function which does exactly the same with less typing:

count(mtcars, cyl, gear)          # or mtcars %>% count(cyl, gear)
#Source: local data frame [8 x 3]
#Groups: cyl [?]
#
#    cyl  gear     n
#  (dbl) (dbl) (int)
#1     4     3     1
#2     4     4     8
#3     4     5     2
#4     6     3     2
#5     6     4     4
#6     6     5     1
#7     8     3    12
#8     8     5     2

How do I get the type of a variable?

I believe I have a valid use case for using typeid(), the same way it is valid to use sizeof(). For a template function, I need to special case the code based on the template variable, so that I offer maximum functionality and flexibility.

It is much more compact and maintainable than using polymorphism, to create one instance of the function for each type supported. Even in that case I might use this trick to write the body of the function only once:

Note that because the code uses templates, the switch statement below should resolve statically into only one code block, optimizing away all the false cases, AFAIK.

Consider this example, where we may need to handle a conversion if T is one type vs another. I use it for class specialization to access hardware where the hardware will use either myClassA or myClassB type. On a mismatch, I need to spend time converting the data.

switch ((typeid(T)) {
  case typeid(myClassA):
    // handle that case
    break;
  case typeid(myClassB):
    // handle that case
    break;
  case typeid(uint32_t):
    // handle that case
    break;
  default:
    // handle that case
}

Generating 8-character only UUIDs

It is not possible since a UUID is a 16-byte number per definition. But of course, you can generate 8-character long unique strings (see the other answers).

Also be careful with generating longer UUIDs and substring-ing them, since some parts of the ID may contain fixed bytes (e.g. this is the case with MAC, DCE and MD5 UUIDs).

How can I generate an ObjectId with mongoose?

I needed to generate mongodb ids on client side.

After digging into the mongodb source code i found they generate ObjectIDs using npm bson lib.

If ever you need only to generate an ObjectID without installing the whole mongodb / mongoose package, you can import the lighter bson library :

const bson = require('bson');
new bson.ObjectId(); // 5cabe64dcf0d4447fa60f5e2

Note: There is also an npm project named bson-objectid being even lighter

Complete list of reasons why a css file might not be working

I'm using Wordpress and the stylesheet was set to enqueue to the footer

wp_enqueue_style(
        'editor-css',
        $stylesheet_directory_uri . '/assets/css/editor.css',
        ['wp-edit-blocks'],
        null,
        true   // $in_footer
    );
}

This resulted in a media="1" attribute getting added to the <link> tag and resulted in the stylesheet being loaded but not applied.

Changed the parameter to false and its working now

How to prettyprint a JSON file?

Use this function and don't sweat having to remember if your JSON is a str or dict again - just look at the pretty print:

import json

def pp_json(json_thing, sort=True, indents=4):
    if type(json_thing) is str:
        print(json.dumps(json.loads(json_thing), sort_keys=sort, indent=indents))
    else:
        print(json.dumps(json_thing, sort_keys=sort, indent=indents))
    return None

pp_json(your_json_string_or_dict)

Command to get nth line of STDOUT

Hmm

sed did not work in my case. I propose:

for "odd" lines 1,3,5,7... ls |awk '0 == (NR+1) % 2'

for "even" lines 2,4,6,8 ls |awk '0 == (NR) % 2'

Triggering change detection manually in Angular

ChangeDetectorRef.detectChanges() - similar to $scope.$digest() -- i.e., check only this component and its children

Can I install the "app store" in an IOS simulator?

This is NOT possible

The Simulator does not run ARM code, ONLY x86 code. Unless you have the raw source code from Apple, you won't see the App Store on the Simulator.

The app you write you will be able to test in the Simulator by running it directly from Xcode even if you don't have a developer account. To test your app on an actual device, you will need to be apart of the Apple Developer program.

Objective-C and Swift URL encoding

 NSString * encodedString = (NSString *)CFURLCreateStringByAddingPercentEscapes(NUL,(CFStringRef)@"parameter",NULL,(CFStringRef)@"!*'();@&+$,/?%#[]~=_-.:",kCFStringEncodingUTF8 );

NSURL * url = [[NSURL alloc] initWithString:[@"address here" stringByAppendingFormat:@"?cid=%@",encodedString, nil]];

How to select data where a field has a min value in MySQL?

This is how I would do it (assuming I understand the question)

SELECT * FROM pieces ORDER BY price ASC LIMIT 1

If you are trying to select multiple rows where each of them may have the same price (which is the minimum) then @JohnWoo's answer should suffice.

Basically here we are just ordering the results by the price in ASCending order (increasing) and taking the first row of the result.

Android Emulator Error Message: "PANIC: Missing emulator engine program for 'x86' CPUS."

If you are using macOS, add both Android SDK emulator and tools directories to the path:

Step 1: In my case the order was important, first emulator and then tools.

export ANDROID_SDK=$HOME/Library/Android/sdk
export PATH=$ANDROID_SDK/emulator:$ANDROID_SDK/tools:$PATH

Step 2: Reload you .bash_profile Or .bashrc depending on OS

Step 3: Get list of emulators available: $emulator -list-avds

Step 4: Launch emulator from the command line and Replace avd with the name of your emulator $emulator @avd

Don't forget to add the @ symbol.

This was tested with macOS High Sierra 10.13.4 and Android Studio 3.1.2.

Android Studio how to run gradle sync manually?

Android studio should have this button in the toolbar marked "Sync project with Gradle Files"

EDIT: I don't know when it was changed but it now looks like this:

enter image description here

EDIT: This is what it looks like on 3.3.1 enter image description here
OR by going to File -> Sync Project with Gradle Files from the menubar.

Twitter Bootstrap tabs not working: when I click on them nothing happens

Had a problem with Bootstrap tabs recently following their online guidelines, but there's currently an error in their markup example data-tabs="tabs" is missing on <ul> element. Without it using data-toggle on links doesn't work.

Disable webkit's spin buttons on input type="number"?

It seems impossible to prevent spinners from appearing in Opera. As a temporary workaround, you can make room for the spinners. As far as I can tell, the following CSS adds just enough padding, only in Opera:

noindex:-o-prefocus,
input[type=number] {
    padding-right: 1.2em;
}

How to fix error Base table or view not found: 1146 Table laravel relationship table?

Laravel tries to guess the name of the table, you have to specify it directly so that it does not give you that error..

Try this:

class NameModel extends Model {
    public $table = 'name_exact_of_the_table';

I hope that helps!

AngularJS - Passing data between pages

What you should do is create a service to share data between controllers.

Nice tutorial https://www.youtube.com/watch?v=HXpHV5gWgyk

invalid new-expression of abstract class type

If you use C++11, you can use the specifier "override", and it will give you a compiler error if your aren't correctly overriding an abstract method. You probably have a method that doesn't match exactly with an abstract method in the base class, so your aren't actually overriding it.

http://en.cppreference.com/w/cpp/language/override

EXCEL VBA Check if entry is empty or not 'space'

A common trick is to check like this:

trim(TextBox1.Value & vbnullstring) = vbnullstring

this will work for spaces, empty strings, and genuine null values

How can I get dictionary key as variable directly in Python (not by searching from value)?

keys=[i for i in mydictionary.keys()] or keys = list(mydictionary.keys())

How to sort the letters in a string alphabetically in Python

You can do:

>>> a = 'ZENOVW'
>>> ''.join(sorted(a))
'ENOVWZ'

Passing an array as a function parameter in JavaScript

As @KaptajnKold had answered

var x = [ 'p0', 'p1', 'p2' ];
call_me.apply(this, x);

And you don't need to define every parameters for call_me function either. You can just use arguments

function call_me () {
    // arguments is a array consisting of params.
    // arguments[0] == 'p0',
    // arguments[1] == 'p1',
    // arguments[2] == 'p2'
}

Convert boolean to int in Java

import org.apache.commons.lang3.BooleanUtils;
boolean x = true;   
int y= BooleanUtils.toInteger(x);

laravel collection to array

Use all() method - it's designed to return items of Collection:

/**
 * Get all of the items in the collection.
 *
 * @return array
 */
public function all()
{
    return $this->items;
}

How to parse a string into a nullable int

    public static void Main(string[] args)
    {

        var myString = "abc";

        int? myInt = ParseOnlyInt(myString);
        // null

        myString = "1234";

        myInt = ParseOnlyInt(myString);
        // 1234
    }
    private static int? ParseOnlyInt(string s)
    {
        return int.TryParse(s, out var i) ? i : (int?)null;
    }

Twitter Bootstrap - add top space between rows

I added these classes to my bootstrap stylesheet

.voffset  { margin-top: 2px; }
.voffset1 { margin-top: 5px; }
.voffset2 { margin-top: 10px; }
.voffset3 { margin-top: 15px; }
.voffset4 { margin-top: 30px; }
.voffset5 { margin-top: 40px; }
.voffset6 { margin-top: 60px; }
.voffset7 { margin-top: 80px; }
.voffset8 { margin-top: 100px; }
.voffset9 { margin-top: 150px; }

Example

<div class="container">
  <div class="row voffset2">
    <div class="col-lg-12">
      <p>
        Vertically offset text.
      </p>
    </div>
  </div>
</div>

Adjust table column width to content size

maybe problem with margin?

width:auto;
padding: 0px;
margin: 0px

Using Razor within JavaScript

I just wrote this helper function. Put it in App_Code/JS.cshtml:

@using System.Web.Script.Serialization
@helper Encode(object obj)
{
    @(new HtmlString(new JavaScriptSerializer().Serialize(obj)));
}

Then in your example, you can do something like this:

var title = @JS.Encode(Model.Title);

Notice how I don't put quotes around it. If the title already contains quotes, it won't explode. Seems to handle dictionaries and anonymous objects nicely too!

How to change UIButton image in Swift

assume that this is your connected UIButton Name like

@IBOutlet var btn_refresh: UIButton!

your can directly place your image in three modes

 // for normal state
btn_refresh.setImage(UIImage(named: "xxx.png"), forState: UIControlState.Normal)
     // for Highlighted state
      btn_refresh.setImage(UIImage(named: "yyy.png"), forState: UIControlState.Highlighted)

        // for Selected state
         btn_refresh.setImage(UIImage(named: "zzzz.png"), forState: UIControlState.Selected)

on your button action

  //MARK: button_refresh action
@IBAction func button_refresh_touchup_inside(sender: UIButton)
{
    //if you set the image on same  UIButton
    sender.setImage(UIImage(named: "newimage.png"), forState: UIControlState.Normal)

    //if you set the image on another  UIButton
       youranotherbuttonName.setImage(UIImage(named: "newimage.png"), forState: UIControlState.Normal)
}

HTML5 Audio stop function

first you have to set an id for your audio element

in your js :

var ply = document.getElementById('player');

var oldSrc = ply.src;// just to remember the old source

ply.src = "";// to stop the player you have to replace the source with nothing

Best programming based games

A game in which you have to graphically construct and train artificial neural networks in order to control a bug is Bug Brain.

Bug Brain screen shot http://www.infionline.net/~wtnewton/oldcomp/bugbrain.jpg

angularjs getting previous route path

modification for the code above:

$scope.$on('$locationChangeStart',function(evt, absNewUrl, absOldUrl) {
   console.log('prev path: ' + absOldUrl.$$route.originalPath);
});

How to autowire RestTemplate using annotations

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;

@Configuration
public class RestTemplateClient {
    @Bean
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

Getting request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource

Basically, to make a cross domain AJAX requests, the requested server should allow the cross origin sharing of resources (CORS). You can read more about that from here: http://www.html5rocks.com/en/tutorials/cors/

In your scenario, you are setting the headers in the client which in fact needs to be set into http://localhost:8080/app server side code.

If you are using PHP Apache server, then you will need to add following in your .htaccess file:

Header set Access-Control-Allow-Origin "*"

VBA: Selecting range by variables

I ran into something similar - I wanted to create a range based on some variables. Using the Worksheet.Cells did not work directly since I think the cell's values were passed to Range.

This did work though:

Range(Cells(1, 1).Address(), Cells(lastRow, lastColumn).Address()).Select

That took care of converting the cell's numerical location to what Range expects, which is the A1 format.

using sql count in a case statement

The reason you're getting two rows instead of one is that you are grouping by rsp_ind in the outer query (which you did not, to my disappointment, share with us). There is nothing you can do to force one row instead of two without dealing with that GROUP BY item.

load Js file in HTML

If this is your detail.html I don't see where do you load detail.js? Maybe this

<script src="js/index.js"></script>

should be this

<script src="js/detail.js"></script>

?

How to set an button align-right with Bootstrap?

Try this:

<div class="row">
<div class="alert alert-info" style="min-height:100px;">
    <div class="col-xs-9">
        <a href="#" class="alert-link">Summary:Its some
           description.......testtesttest</a>  
    </div>
    <div class="col-xs-3">
        <button type="button" class="btn btn-primary btn-lg">Large      button</button>
    </div>
 </div>
</div>

Demo:

http://jsfiddle.net/Hx6Sx/1/

Element-wise addition of 2 lists?

This is simple with numpy.add()

import numpy

list1 = numpy.array([1, 2, 3])
list2 = numpy.array([4, 5, 6])
result = numpy.add(list1, list2) # result receive element-wise addition of list1 and list2
print(result)
array([5, 7, 9])

See doc here

If you want to receiver a python list:

result.tolist()

How to access array elements in a Django template?

You can access sequence elements with arr.0 arr.1 and so on. See The Django template system chapter of the django book for more information.

creating Hashmap from a JSON String

Parse the JSONObject and create HashMap

public static void jsonToMap(String t) throws JSONException {

        HashMap<String, String> map = new HashMap<String, String>();
        JSONObject jObject = new JSONObject(t);
        Iterator<?> keys = jObject.keys();

        while( keys.hasNext() ){
            String key = (String)keys.next();
            String value = jObject.getString(key); 
            map.put(key, value);

        }

        System.out.println("json : "+jObject);
        System.out.println("map : "+map);
    }

Tested output:

json : {"phonetype":"N95","cat":"WP"}
map : {cat=WP, phonetype=N95}

Starting ssh-agent on Windows 10 fails: "unable to start ssh-agent service, error :1058"

I solved the problem by changing the StartupType of the ssh-agent to Manual via Set-Service ssh-agent -StartupType Manual.

Then I was able to start the service via Start-Service ssh-agent or just ssh-agent.exe.

How to compare LocalDate instances Java 8

LocalDate ld ....;
LocalDateTime ldtime ...;

ld.isEqual(LocalDate.from(ldtime));

Splitting a string into separate variables

Like this?

$string = 'FirstPart SecondPart'
$a,$b = $string.split(' ')
$a
$b

SQL Server query to find all permissions/access for all users in a database

I just added the following to Jeremy's answer because I had a role assigned to the database db_datareader which wasn't showing the permissions that role had. I tried going through all of the answers in everyone's posts but couldn't find anything that would do this so I added my own query.

    SELECT 
    UserType='Role', 
    DatabaseUserName = '{Role Members}',
    LoginName = DP2.name,
    Role = DP1.name,
    'SELECT' AS [PermissionType] ,
    [PermissionState]  = 'GRANT',
    [ObjectType] = 'Table',
    [Schema] = 'dbo',
    [ObjectName] = 'All Tables',
    [ColumnName] = NULL
FROM sys.database_role_members AS DRM  
RIGHT OUTER JOIN sys.database_principals AS DP1  
    ON DRM.role_principal_id = DP1.principal_id  
LEFT OUTER JOIN sys.database_principals AS DP2  
    ON DRM.member_principal_id = DP2.principal_id  
WHERE DP1.type = 'R'
AND DP2.name IS NOT NULL

What does '<?=' mean in PHP?

As of PHP 5.4.0, <?= ?> are always available even without the short_open_tag set in php.ini.

Furthermore, as of PHP 7.0, The ASP tags: <%, %> and the script tag <script language="php"> are removed from PHP.

How does the getView() method work when creating your own custom adapter?

getView() method in Adapter is for generating item's view of a ListView, Gallery,...

  1. LayoutInflater is used to get the View object which you define in a layout xml (the root object, normally a LinearLayout, FrameLayout, or RelativeLayout)

  2. convertView is for recycling. Let's say you have a listview which can only display 10 items at a time, and currently it is displaying item 1 -> item 10. When you scroll down one item, the item 1 will be out of screen, and item 11 will be displayed. To generate View for item 11, the getView() method will be called, and convertView here is the view of item 1 (which is not neccessary anymore). So instead create a new View object for item 11 (which is costly), why not re-use convertView? => we just check convertView is null or not, if null create new view, else re-use convertView.

  3. parentView is the ListView or Gallery... which contains the item's view which getView() generates.

Note: you don't call this method directly, just need to implement it to tell the parent view how to generate the item's view.

Add new row to dataframe, at specific row-index, not appended?

for example you want to add rows of variable 2 to variable 1 of a data named "edges" just do it like this

allEdges <- data.frame(c(edges$V1,edges$V2))

How to reset all checkboxes using jQuery or pure JS?

I have used this before:

$('input[type=checkbox]').prop('checked', false);

seems that .attr and .removeAttr doesn't work for some situations.

edit: Note that in jQuery v1.6 and higher, you should be using .prop('checked', false) instead for greater cross-browser compatibility - see https://api.jquery.com/prop

Comment here: How to reset all checkboxes using jQuery or pure JS?

How do I find the data directory for a SQL Server instance?

Keeping it simple:

use master
select DB.name, F.physical_name from sys.databases DB join sys.master_files F on DB.database_id=F.database_id

this will return all databases with associated files

Numpy ValueError: setting an array element with a sequence. This message may appear without the existing of a sequence?

It's a pity that both of the answers analyze the problem but didn't give a direct answer. Let's see the code.

Z = np.array([1.0, 1.0, 1.0, 1.0])  

def func(TempLake, Z):
    A = TempLake
    B = Z
    return A * B
Nlayers = Z.size
N = 3
TempLake = np.zeros((N+1, Nlayers))
kOUT = np.zeros(N + 1)

for i in xrange(N):
    # store the i-th result of
    # function "func" in i-th item in kOUT
    kOUT[i] = func(TempLake[i], Z)

The error shows that you set the ith item of kOUT(dtype:int) into an array. Here every item in kOUT is an int, can't directly assign to another datatype. Hence you should declare the data type of kOUT when you create it. For example, like:

Change the statement below:

kOUT = np.zeros(N + 1)

into:

kOUT = np.zeros(N + 1, dtype=object)

or:

kOUT = np.zeros((N + 1, N + 1))

All code:

import numpy as np
Z = np.array([1.0, 1.0, 1.0, 1.0])

def func(TempLake, Z):
    A = TempLake
    B = Z
    return A * B

Nlayers = Z.size
N = 3
TempLake = np.zeros((N + 1, Nlayers))

kOUT = np.zeros(N + 1, dtype=object)
for i in xrange(N):
    kOUT[i] = func(TempLake[i], Z)

Hope it can help you.

How to do SELECT MAX in Django?

Django also has the 'latest(field_name = None)' function that finds the latest (max. value) entry. It not only works with date fields but also with strings and integers.

You can give the field name when calling that function:

max_rated_entry = YourModel.objects.latest('rating')
return max_rated_entry.details

Or you can already give that field name in your models meta data:

from django.db import models

class YourModel(models.Model):
    #your class definition
    class Meta:
        get_latest_by = 'rating'

Now you can call 'latest()' without any parameters:

max_rated_entry = YourModel.objects.latest()
return max_rated_entry.details

Creating the checkbox dynamically using JavaScript?

The last line should read

cbh.appendChild(document.createTextNode(cap));

Appending the text (label?) to the same container as the checkbox, not the checkbox itself

How to detect a textbox's content has changed

I would recommend taking a look at jQuery UI autocomplete widget. They handled most of the cases there since their code base is more mature than most ones out there.

Below is a link to a demo page so you can verify it works. http://jqueryui.com/demos/autocomplete/#default

You will get the most benefit from reading the source and seeing how they solved it. You can find it here: https://github.com/jquery/jquery-ui/blob/master/ui/jquery.ui.autocomplete.js.

Basically they do it all, they bind to input, keydown, keyup, keypress, focus and blur. Then they have special handling for all sorts of keys like page up, page down, up arrow key and down arrow key. A timer is used before getting the contents of the textbox. When a user types a key that does not correspond to a command (up key, down key and so on) there is a timer that explorers the content after about 300 milliseconds. It looks like this in the code:

// switch statement in the 
switch( event.keyCode ) {
            //...
            case keyCode.ENTER:
            case keyCode.NUMPAD_ENTER:
                // when menu is open and has focus
                if ( this.menu.active ) {
                    // #6055 - Opera still allows the keypress to occur
                    // which causes forms to submit
                    suppressKeyPress = true;
                    event.preventDefault();
                    this.menu.select( event );
                }
                break;
            default:
                suppressKeyPressRepeat = true;
                // search timeout should be triggered before the input value is changed
                this._searchTimeout( event );
                break;
            }
// ...
// ...
_searchTimeout: function( event ) {
    clearTimeout( this.searching );
    this.searching = this._delay(function() { // * essentially a warpper for a setTimeout call *
        // only search if the value has changed
        if ( this.term !== this._value() ) { // * _value is a wrapper to get the value *
            this.selectedItem = null;
            this.search( null, event );
        }
    }, this.options.delay );
},

The reason to use a timer is so that the UI gets a chance to be updated. When Javascript is running the UI cannot be updated, therefore the call to the delay function. This works well for other situations such as keeping focus on the textbox (used by that code).

So you can either use the widget or copy the code into your own widget if you are not using jQuery UI (or in my case developing a custom widget).

rake assets:precompile RAILS_ENV=production not working as required

Have you added this gem to your gemfile?

# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'

move that gem out of assets group and then run bundle again, I hope that would help!

Creating watermark using html and css

Other solutions are great but they didn't take care of the fact that watermark shouldn't get selected on selection from the mouse. This fiddle takes care or that: https://jsfiddle.net/MiKr13/d1r4o0jg/9/

This will be better option for pdf or static html.

CSS:

#watermark {
  opacity: 0.2;
  font-size: 52px;
  color: 'black';
  background: '#ccc';
  position: absolute;
  cursor: default;
  user-select: none;
  -webkit-user-select: none;
  -khtml-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  right: 5px;
  bottom: 5px;
}

Should __init__() call the parent class's __init__()?

In Anon's answer:
"If you need something from super's __init__ to be done in addition to what is being done in the current class's __init__ , you must call it yourself, since that will not happen automatically"

It's incredible: he is wording exactly the contrary of the principle of inheritance.


It is not that "something from super's __init__ (...) will not happen automatically" , it is that it WOULD happen automatically, but it doesn't happen because the base-class' __init__ is overriden by the definition of the derived-clas __init__

So then, WHY defining a derived_class' __init__ , since it overrides what is aimed at when someone resorts to inheritance ??

It's because one needs to define something that is NOT done in the base-class' __init__ , and the only possibility to obtain that is to put its execution in a derived-class' __init__ function.
In other words, one needs something in base-class' __init__ in addition to what would be automatically done in the base-classe' __init__ if this latter wasn't overriden.
NOT the contrary.


Then, the problem is that the desired instructions present in the base-class' __init__ are no more activated at the moment of instantiation. In order to offset this inactivation, something special is required: calling explicitly the base-class' __init__ , in order to KEEP , NOT TO ADD, the initialization performed by the base-class' __init__ . That's exactly what is said in the official doc:

An overriding method in a derived class may in fact want to extend rather than simply replace the base class method of the same name. There is a simple way to call the base class method directly: just call BaseClassName.methodname(self, arguments).
http://docs.python.org/tutorial/classes.html#inheritance

That's all the story:

  • when the aim is to KEEP the initialization performed by the base-class, that is pure inheritance, nothing special is needed, one must just avoid to define an __init__ function in the derived class

  • when the aim is to REPLACE the initialization performed by the base-class, __init__ must be defined in the derived-class

  • when the aim is to ADD processes to the initialization performed by the base-class, a derived-class' __init__ must be defined , comprising an explicit call to the base-class __init__


What I feel astonishing in the post of Anon is not only that he expresses the contrary of the inheritance theory, but that there have been 5 guys passing by that upvoted without turning a hair, and moreover there have been nobody to react in 2 years in a thread whose interesting subject must be read relatively often.

What does cmd /C mean?

The part you should be interested in is the /? part, which should solve most other questions you have with the tool.

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\>cmd /?
Starts a new instance of the Windows XP command interpreter

CMD [/A | /U] [/Q] [/D] [/E:ON | /E:OFF] [/F:ON | /F:OFF] [/V:ON | /V:OFF]
    [[/S] [/C | /K] string]

/C      Carries out the command specified by string and then terminates
/K      Carries out the command specified by string but remains
/S      Modifies the treatment of string after /C or /K (see below)
/Q      Turns echo off
/D      Disable execution of AutoRun commands from registry (see below)
/A      Causes the output of internal commands to a pipe or file to be ANSI
/U      Causes the output of internal commands to a pipe or file to be
        Unicode
/T:fg   Sets the foreground/background colors (see COLOR /? for more info)
/E:ON   Enable command extensions (see below)
/E:OFF  Disable command extensions (see below)
/F:ON   Enable file and directory name completion characters (see below)
/F:OFF  Disable file and directory name completion characters (see below)
/V:ON   Enable delayed environment variable expansion using ! as the
        delimiter. For example, /V:ON would allow !var! to expand the
        variable var at execution time.  The var syntax expands variables
        at input time, which is quite a different thing when inside of a FOR
        loop.
/V:OFF  Disable delayed environment expansion.

Assign null to a SqlParameter

            dynamic psd = DBNull.Value;

            if (schedule.pushScheduleDate > DateTime.MinValue)
            {
                psd = schedule.pushScheduleDate;
            }


            sql.DBController.RunGeneralStoredProcedureNonQuery("SchedulePush",
                     new string[] { "@PushScheduleDate"},
                     new object[] { psd }, 10, "PushCenter");

Reading int values from SqlDataReader

based on Sam Holder's answer, you could make an extension method for that

namespace adonet.extensions
{
  public static class AdonetExt
  {
    public static int GetInt32(this SqlDataReader reader, string columnName)
    {
      return reader.GetInt32(reader.GetOrdinal(columnName));
    }
  }
}

and use it like this

using adonet.extensions;

//...

int farmsize = reader.GetInt32("farmsize");

assuming there is no GetInt32(string) already in SqlDataReader - if there is any, just use some other method name instead

what's the default value of char?

The default char is the character with an int value of 0 (zero).

char NULLCHAR = (char) 0;

char NULLCHAR = '\0';

Get JSON Data from URL Using Android?

If you get the server response as a String, without using a third party library you can do

JSONObject json = new JSONObject(response);
JSONObject jsonResponse = json.getJSONObject("response");
String team = jsonResponse.getString("Team");

Here is the documentation

Otherwise to parse json you can use Gson or Jackson

EDIT without libraries (not tested)

class retrievedata extends AsyncTask<Void, Void, String>{
    @Override
    protected String doInBackground(Void... params) {

        HttpURLConnection urlConnection = null;
        BufferedReader reader = null;

        URL url;
        try {
            url = new URL("http://myurlhere.com");
            urlConnection.setRequestMethod("GET"); //Your method here 
            urlConnection.connect();

            InputStream inputStream = urlConnection.getInputStream();
            StringBuffer buffer = new StringBuffer();
            if (inputStream == null) {
                return null;
            }
            reader = new BufferedReader(new InputStreamReader(inputStream));

            String line;
            while ((line = reader.readLine()) != null)
                buffer.append(line + "\n");

            if (buffer.length() == 0)
                return null;

            return buffer.toString();
        } catch (IOException e) {
            Log.e(TAG, "IO Exception", e);
            exception = e;
            return null;
        } finally {
            if (urlConnection != null) {
                urlConnection.disconnect();
            }
            if (reader != null) {
                try {
                    reader.close();
                } catch (final IOException e) {
                    exception = e;
                    Log.e(TAG, "Error closing stream", e);
                }
            }
        }
    }

    @Override
    protected void onPostExecute(String response) {
        if(response != null) {
            JSONObject json = new JSONObject(response);
            JSONObject jsonResponse = json.getJSONObject("response");
            String team = jsonResponse.getString("Team");
        }
    }
}

Set icon for Android application

Define the icon for android application

<application android:icon="drawable resource">
.... 
</application> 

https://developer.android.com/guide/topics/manifest/application-element.html


If your app available across large range of devices

You should create separate icons for all generalized screen densities, including low-, medium-, high-, and extra-high-density screens. This ensures that your icons will display properly across the range of devices on which your application can be installed...

enter image description here


Size & Format

Launcher icons should be 32-bit PNGs with an alpha channel for transparency. The finished launcher icon dimensions corresponding to a given generalized screen density are shown in the table below.

enter image description here


Place icon in mipmap or drawable folder

android:icon="@drawable/icon_name" or android:icon="@mipmap/icon_name"

developer.android.com/guide says,

This attribute must be set as a reference to a drawable resource containing the image (for example "@drawable/icon").

about launcher icons android-developers.googleblog.com says,

It’s best practice to place your app icons in mipmap- folders (not the drawable- folders) because they are used at resolutions different from the device’s current density. For example, an xxxhdpi app icon can be used on the launcher for an xxhdpi device.

Dianne Hackborn from Google (Android Framework) says,

If you are building different versions of your app for different densities, you should know about the "mipmap" resource directory. This is exactly like "drawable" resources, except it does not participate in density stripping when creating the different apk targets.

For launcher icons, the AndroidManifest.xml file must reference the mipmap/ location

<application android:name="ApplicationTitle"
         android:label="@string/app_label"
         android:icon="@mipmap/ic_launcher" >

Little bit more quoting this

  1. You want to load an image for your device density and you are going to use it "as is", without changing its actual size. In this case you should work with drawables and Android will give you the best fitting image.

  2. You want to load an image for your device density, but this image is going to be scaled up or down. For instance this is needed when you want to show a bigger launcher icon, or you have an animation, which increases image's size. In such cases, to ensure best image quality, you should put your image into mipmap folder. What Android will do is, it will try to pick up the image from a higher density bucket instead of scaling it up. This will increase sharpness (quality) of the image.

Fore more you can read mipmap vs drawable folders


Tools to easily generate assets

  1. Android Asset Studio by romannurik.github
  2. Android Asset Studio by jgilfelt.github
  3. Image Asset Studio(from Android Studio)
  4. Material Icon Generator.bitdroid.de
  5. Android Material Design Icon Generator Plugin by github.com/konifar
  6. A script to generate android assets from a SVG file

Read more : https://developer.android.com/guide/practices/ui_guidelines/icon_design_launcher.html

How to change the Title of the window in Qt?

void    QWidget::setWindowTitle ( const QString & )

EDIT: If you are using QtDesigner, on the property tab, there is an editable property called windowTitle which can be found under the QWidget section. The property tab can usually be found on the lower right part of the designer window.

How to deal with INSTALL_PARSE_FAILED_INCONSISTENT_CERTIFICATES without uninstall?

Just delete the old build from the device and reinstall the same. Because device.keystore is already exist in the device so just uninstall the build and reinstall the APK thats all..

Thanks

Send mail via CMD console

From Linux you can use 'swaks' which is available as an official packages on many distros including Debian/Ubuntu and Redhat/CentOS on EPEL:

swaks -f [email protected] -t [email protected] \
    --server mail.example.com

LINQ query to find if items in a list are contained in another list

No need to use Linq like this here, because there already exists an extension method to do this for you.

Enumerable.Except<TSource>

http://msdn.microsoft.com/en-us/library/bb336390.aspx

You just need to create your own comparer to compare as needed.

How do I close a tkinter window?

Try this:

from Tkinter import *
import sys
def exitApp():
    sys.exit()
root = Tk()
Button(root, text="Quit", command=exitApp).pack()
root.mainloop()

Get current URL path in PHP

it should be :

$_SERVER['REQUEST_URI'];

Take a look at : Get the full URL in PHP

How to programmatically set the layout_align_parent_right attribute of a Button in Relative Layout?

For adding a RelativeLayout attribute whose value is true or false use 0 for false and RelativeLayout.TRUE for true:

RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) button.getLayoutParams()
params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, RelativeLayout.TRUE)

It doesn't matter whether or not the attribute was already added, you still use addRule(verb, subject) to enable/disable it. However, post-API 17 you can use removeRule(verb) which is just a shortcut for addRule(verb, 0).

Maven Unable to locate the Javac Compiler in:

I am able to resolved by doing following steps :

Right click on project select Build path -> Configure build path -> select Libraries Tab -> then select JRE System Library[version you have for me its JavaSE-1.7] - > click Edit button -> In JRE System Library window select Execution environment - In drop down you can select the JDK listed for me its JavaSE-1.7 -> next to this click to Environments button -> In Execution Environments window you have to again select your java SE for me its JavaSE-1.7 -> just select it, you will have options in Compatible JREs tab, so select JDK that you want to have in my case its jdk1.7.0_25.


Click ok and finish the rest windows by doing appropriate action Ok/Finish.

Lastly do Maven Clean and Maven Install.

How do I get the IP address into a batch-file variable?

In linux environment:

ip="$(ifconfig eth0 | grep "inet addr:" | awk '{print $2}' | cut -d ':' -f 2)"

or

ip="$(ifconfig eth0 | grep "inet addr:" | awk '{print $2}' | cut -d ':' -f 2)" | echo $ip

example in FreeBSD:

ifconfig re0 | grep -v "inet6" | grep -i "inet" | awk '{print $2}'

If you have more than one IP address configured, you will have more than one IP address in stdout.

iOS 7.0 No code signing identities found

I had this ambiguous error, "Command /usr/bin/codesign failed with exit code 1", when I was setting up new Jenkins boxes for iOS builds with Xcode 7.3, OSX 10.11.4.

In my case I had several things right: 1.Yes I had added my certificates to the keychain, both Apple's root and the team's cert. 2.Yes I downloaded the correct provisioning profile via xcode preferences. 3.Yes it even built manually in xcode.

However, for jenkins, there was perhaps a caching issue on xcode. What worked was: 1.Exit the Xcode GUI. 2.Get back in, and run the build manually once. 3.Only then will Xcode prompt to allow keychain access authorization. 4.Jenkins has some settings that might be able to fix this, but my machines are secure, so I click 'always allow xcode to access the keychain'.

Calling an API from SQL Server stored procedure

I'd recommend using a CLR user defined function, if you already know how to program in C#, then the code would be;

using System.Data.SqlTypes;
using System.Net;

public partial class UserDefinedFunctions
{
 [Microsoft.SqlServer.Server.SqlFunction]
 public static SqlString http(SqlString url)
 {
  var wc = new WebClient();
  var html = wc.DownloadString(url.Value);
  return new SqlString (html);
 }
}

And here's installation instructions; https://blog.dotnetframework.org/2019/09/17/make-a-http-request-from-sqlserver-using-a-clr-udf/

How to read an entire file to a string using C#?

if you want to pick file from Bin folder of the application then you can try following and don't forget to do exception handling.

string content = File.ReadAllText(Path.Combine(System.IO.Directory.GetCurrentDirectory(), @"FilesFolder\Sample.txt"));

Increasing heap space in Eclipse: (java.lang.OutOfMemoryError)

I am not pro in Java but your problem can be solved by "blockingqueue" if you use it wisely.

Try to retrieve a chunk of records first, process them, and iterate the process until you complete your processing. This may help you to get rid of the OutOfMemory Exceptions.

How to print color in console using System.out.println?

Here are a list of colors in a Java class with public static fields

Usage

System.out.println(ConsoleColors.RED + "RED COLORED" +
ConsoleColors.RESET + " NORMAL");


Note Don't forget to use the RESET after printing as the effect will remain if it's not cleared


public class ConsoleColors {
    // Reset
    public static final String RESET = "\033[0m";  // Text Reset

    // Regular Colors
    public static final String BLACK = "\033[0;30m";   // BLACK
    public static final String RED = "\033[0;31m";     // RED
    public static final String GREEN = "\033[0;32m";   // GREEN
    public static final String YELLOW = "\033[0;33m";  // YELLOW
    public static final String BLUE = "\033[0;34m";    // BLUE
    public static final String PURPLE = "\033[0;35m";  // PURPLE
    public static final String CYAN = "\033[0;36m";    // CYAN
    public static final String WHITE = "\033[0;37m";   // WHITE

    // Bold
    public static final String BLACK_BOLD = "\033[1;30m";  // BLACK
    public static final String RED_BOLD = "\033[1;31m";    // RED
    public static final String GREEN_BOLD = "\033[1;32m";  // GREEN
    public static final String YELLOW_BOLD = "\033[1;33m"; // YELLOW
    public static final String BLUE_BOLD = "\033[1;34m";   // BLUE
    public static final String PURPLE_BOLD = "\033[1;35m"; // PURPLE
    public static final String CYAN_BOLD = "\033[1;36m";   // CYAN
    public static final String WHITE_BOLD = "\033[1;37m";  // WHITE

    // Underline
    public static final String BLACK_UNDERLINED = "\033[4;30m";  // BLACK
    public static final String RED_UNDERLINED = "\033[4;31m";    // RED
    public static final String GREEN_UNDERLINED = "\033[4;32m";  // GREEN
    public static final String YELLOW_UNDERLINED = "\033[4;33m"; // YELLOW
    public static final String BLUE_UNDERLINED = "\033[4;34m";   // BLUE
    public static final String PURPLE_UNDERLINED = "\033[4;35m"; // PURPLE
    public static final String CYAN_UNDERLINED = "\033[4;36m";   // CYAN
    public static final String WHITE_UNDERLINED = "\033[4;37m";  // WHITE

    // Background
    public static final String BLACK_BACKGROUND = "\033[40m";  // BLACK
    public static final String RED_BACKGROUND = "\033[41m";    // RED
    public static final String GREEN_BACKGROUND = "\033[42m";  // GREEN
    public static final String YELLOW_BACKGROUND = "\033[43m"; // YELLOW
    public static final String BLUE_BACKGROUND = "\033[44m";   // BLUE
    public static final String PURPLE_BACKGROUND = "\033[45m"; // PURPLE
    public static final String CYAN_BACKGROUND = "\033[46m";   // CYAN
    public static final String WHITE_BACKGROUND = "\033[47m";  // WHITE

    // High Intensity
    public static final String BLACK_BRIGHT = "\033[0;90m";  // BLACK
    public static final String RED_BRIGHT = "\033[0;91m";    // RED
    public static final String GREEN_BRIGHT = "\033[0;92m";  // GREEN
    public static final String YELLOW_BRIGHT = "\033[0;93m"; // YELLOW
    public static final String BLUE_BRIGHT = "\033[0;94m";   // BLUE
    public static final String PURPLE_BRIGHT = "\033[0;95m"; // PURPLE
    public static final String CYAN_BRIGHT = "\033[0;96m";   // CYAN
    public static final String WHITE_BRIGHT = "\033[0;97m";  // WHITE

    // Bold High Intensity
    public static final String BLACK_BOLD_BRIGHT = "\033[1;90m"; // BLACK
    public static final String RED_BOLD_BRIGHT = "\033[1;91m";   // RED
    public static final String GREEN_BOLD_BRIGHT = "\033[1;92m"; // GREEN
    public static final String YELLOW_BOLD_BRIGHT = "\033[1;93m";// YELLOW
    public static final String BLUE_BOLD_BRIGHT = "\033[1;94m";  // BLUE
    public static final String PURPLE_BOLD_BRIGHT = "\033[1;95m";// PURPLE
    public static final String CYAN_BOLD_BRIGHT = "\033[1;96m";  // CYAN
    public static final String WHITE_BOLD_BRIGHT = "\033[1;97m"; // WHITE

    // High Intensity backgrounds
    public static final String BLACK_BACKGROUND_BRIGHT = "\033[0;100m";// BLACK
    public static final String RED_BACKGROUND_BRIGHT = "\033[0;101m";// RED
    public static final String GREEN_BACKGROUND_BRIGHT = "\033[0;102m";// GREEN
    public static final String YELLOW_BACKGROUND_BRIGHT = "\033[0;103m";// YELLOW
    public static final String BLUE_BACKGROUND_BRIGHT = "\033[0;104m";// BLUE
    public static final String PURPLE_BACKGROUND_BRIGHT = "\033[0;105m"; // PURPLE
    public static final String CYAN_BACKGROUND_BRIGHT = "\033[0;106m";  // CYAN
    public static final String WHITE_BACKGROUND_BRIGHT = "\033[0;107m";   // WHITE
}

PL/SQL ORA-01422: exact fetch returns more than requested number of rows

It can also be due to a duplicate entry in any of the tables that are used.

how to convert rgb color to int in java

Use getRGB(), it helps ( no complicated programs )

Returns an array of integer pixels in the default RGB color model (TYPE_INT_ARGB) and default sRGB color space, from a portion of the image data.

Where to declare variable in react js

Using ES6 syntax in React does not bind this to user-defined functions however it will bind this to the component lifecycle methods.

So the function that you declared will not have the same context as the class and trying to access this will not give you what you are expecting.

For getting the context of class you have to bind the context of class to the function or use arrow functions.

Method 1 to bind the context:

class MyContainer extends Component {

    constructor(props) {
        super(props);
        this.onMove = this.onMove.bind(this);
        this.testVarible= "this is a test";
    }

    onMove() {
        console.log(this.testVarible);
    }
}

Method 2 to bind the context:

class MyContainer extends Component {

    constructor(props) {
        super(props);
        this.testVarible= "this is a test";
    }

    onMove = () => {
        console.log(this.testVarible);
    }
}

Method 2 is my preferred way but you are free to choose your own.

Update: You can also create the properties on class without constructor:

class MyContainer extends Component {

    testVarible= "this is a test";

    onMove = () => {
        console.log(this.testVarible);
    }
}

Note If you want to update the view as well, you should use state and setState method when you set or change the value.

Example:

class MyContainer extends Component {

    state = { testVarible: "this is a test" };

    onMove = () => {
        console.log(this.state.testVarible);
        this.setState({ testVarible: "new value" });
    }
}

PostgreSQL wildcard LIKE for any of a list of words

Actually there is an operator for that in PostgreSQL:

SELECT *
FROM table
WHERE lower(value) ~~ ANY('{%foo%,%bar%,%baz%}');

How to SUM parts of a column which have same text value in different column in the same row

If your data has the names grouped as shown then you can use this formula in D2 copied down to get a total against the last entry for each name

=IF((A2=A3)*(B2=B3),"",SUM(C$2:C2)-SUM(D$1:D1))

See screenshot

enter image description here

Shall we always use [unowned self] inside closure in Swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.

        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let controller = storyboard.instantiateViewController(withIdentifier: "AnotherViewController")
        self.navigationController?.pushViewController(controller, animated: true)

    }

}



import UIKit
class AnotherViewController: UIViewController {

    var name : String!

    deinit {
        print("Deint AnotherViewController")
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        print(CFGetRetainCount(self))

        /*
            When you test please comment out or vice versa

         */

//        // Should not use unowned here. Because unowned is used where not deallocated. or gurranted object alive. If you immediate click back button app will crash here. Though there will no retain cycles
//        clouser(string: "") { [unowned self] (boolValue)  in
//            self.name = "some"
//        }
//


//
//        // There will be a retain cycle. because viewcontroller has a strong refference to this clouser and as well as clouser (self.name) has a strong refferennce to the viewcontroller. Deint AnotherViewController will not print
//        clouser(string: "") { (boolValue)  in
//            self.name = "some"
//        }
//
//


//        // no retain cycle here. because viewcontroller has a strong refference to this clouser. But clouser (self.name) has a weak refferennce to the viewcontroller. Deint AnotherViewController will  print. As we forcefully made viewcontroller weak so its now optional type. migh be nil. and we added a ? (self?)
//
//        clouser(string: "") { [weak self] (boolValue)  in
//            self?.name = "some"
//        }


        // no retain cycle here. because viewcontroller has a strong refference to this clouser. But clouser nos refference to the viewcontroller. Deint AnotherViewController will  print. As we forcefully made viewcontroller weak so its now optional type. migh be nil. and we added a ? (self?)

        clouser(string: "") {  (boolValue)  in
            print("some")
            print(CFGetRetainCount(self))

        }

    }


    func clouser(string: String, completion: @escaping (Bool) -> ()) {
        // some heavy task
        DispatchQueue.main.asyncAfter(deadline: .now() + 5.0) {
            completion(true)
        }

    }

}

If you do not sure about [unowned self] then use [weak self]

How do I delete unpushed git commits?

For your reference, I believe you can "hard cut" commits out of your current branch not only with git reset --hard, but also with the following command:

git checkout -B <branch-name> <SHA>

In fact, if you don't care about checking out, you can set the branch to whatever you want with:

git branch -f <branch-name> <SHA>

This would be a programmatic way to remove commits from a branch, for instance, in order to copy new commits to it (using rebase).

Suppose you have a branch that is disconnected from master because you have taken sources from some other location and dumped it into the branch.

You now have a branch in which you have applied changes, let's call it "topic".

You will now create a duplicate of your topic branch and then rebase it onto the source code dump that is sitting in branch "dump":

git branch topic_duplicate topic
git rebase --onto dump master topic_duplicate

Now your changes are reapplied in branch topic_duplicate based on the starting point of "dump" but only the commits that have happened since "master". So your changes since master are now reapplied on top of "dump" but the result ends up in "topic_duplicate".

You could then replace "dump" with "topic_duplicate" by doing:

git branch -f dump topic_duplicate
git branch -D topic_duplicate

Or with

git branch -M topic_duplicate dump

Or just by discarding the dump

git branch -D dump

Perhaps you could also just cherry-pick after clearing the current "topic_duplicate".

What I am trying to say is that if you want to update the current "duplicate" branch based off of a different ancestor you must first delete the previously "cherrypicked" commits by doing a git reset --hard <last-commit-to-retain> or git branch -f topic_duplicate <last-commit-to-retain> and then copying the other commits over (from the main topic branch) by either rebasing or cherry-picking.

Rebasing only works on a branch that already has the commits, so you need to duplicate your topic branch each time you want to do that.

Cherrypicking is much easier:

git cherry-pick master..topic

So the entire sequence will come down to:

git reset --hard <latest-commit-to-keep>
git cherry-pick master..topic

When your topic-duplicate branch has been checked out. That would remove previously-cherry-picked commits from the current duplicate, and just re-apply all of the changes happening in "topic" on top of your current "dump" (different ancestor). It seems a reasonably convenient way to base your development on the "real" upstream master while using a different "downstream" master to check whether your local changes also still apply to that. Alternatively you could just generate a diff and then apply it outside of any Git source tree. But in this way you can keep an up-to-date modified (patched) version that is based on your distribution's version while your actual development is against the real upstream master.

So just to demonstrate:

  • reset will make your branch point to a different commit (--hard also checks out the previous commit, --soft keeps added files in the index (that would be committed if you commit again) and the default (--mixed) will not check out the previous commit (wiping your local changes) but it will clear the index (nothing has been added for commit yet)
  • you can just force a branch to point to a different commit
  • you can do so while immediately checking out that commit as well
  • rebasing works on commits present in your current branch
  • cherry-picking means to copy over from a different branch

Hope this helps someone. I was meaning to rewrite this, but I cannot manage now. Regards.

How to read data from excel file using c#

Convert the excel file to .csv file (comma separated value file) and now you can easily be able to read it.

What is let-* in Angular 2 templates?

The Angular microsyntax lets you configure a directive in a compact, friendly string. The microsyntax parser translates that string into attributes on the <ng-template>. The let keyword declares a template input variable that you reference within the template.

Why does 2 mod 4 = 2?

For a visual way to think about it, picture a clock face that, in your particular example, only goes to 4 instead of 12. If you start at 4 on the clock (which is like starting at zero) and go around it clockwise for 2 "hours", you land on 2, just like going around it clockwise for 6 "hours" would also land you on 2 (6 mod 4 == 2 just like 2 mod 4 == 2).

php create object without class

you can always use new stdClass(). Example code:

   $object = new stdClass();
   $object->property = 'Here we go';

   var_dump($object);
   /*
   outputs:

   object(stdClass)#2 (1) {
      ["property"]=>
      string(10) "Here we go"
    }
   */

Also as of PHP 5.4 you can get same output with:

$object = (object) ['property' => 'Here we go'];

How to check if memcache or memcached is installed for PHP?

You can look at phpinfo() or check if any of the functions of memcache is available. Ultimately, check whether the Memcache class exists or not.

e.g.

if(class_exists('Memcache')){
  // Memcache is enabled.
}

pandas get rows which are NOT in other dataframe

you can do it using isin(dict) method:

In [74]: df1[~df1.isin(df2.to_dict('l')).all(1)]
Out[74]:
   col1  col2
3     4    13
4     5    14

Explanation:

In [75]: df2.to_dict('l')
Out[75]: {'col1': [1, 2, 3], 'col2': [10, 11, 12]}

In [76]: df1.isin(df2.to_dict('l'))
Out[76]:
    col1   col2
0   True   True
1   True   True
2   True   True
3  False  False
4  False  False

In [77]: df1.isin(df2.to_dict('l')).all(1)
Out[77]:
0     True
1     True
2     True
3    False
4    False
dtype: bool

Error You must specify a region when running command aws ecs list-container-instances

"You must specify a region" is a not an ECS specific error, it can happen with any AWS API/CLI/SDK command.

For the CLI, either set the AWS_DEFAULT_REGION environment variable. e.g.

export AWS_DEFAULT_REGION=us-east-1

or add it into the command (you will need this every time you use a region-specific command)

AWS_DEFAULT_REGION=us-east-1 aws ecs list-container-instances --cluster default

or set it in the CLI configuration file: ~/.aws/config

[default]
region=us-east-1

or pass/override it with the CLI call:

aws ecs list-container-instances --cluster default --region us-east-1

How to identify all stored procedures referring a particular table

SELECT DISTINCT OBJECT_NAME(OBJECT_ID),
object_definition(OBJECT_ID)
FROM sys.Procedures
WHERE object_definition(OBJECT_ID) LIKE '%' + 'table_name' + '%'

GO

This will work if you have to mention the table name.

Set the intervals of x-axis using r

You can use axis:

> axis(side=1, at=c(0:23))

That is, something like this:

plot(0:23, d, type='b', axes=FALSE)
axis(side=1, at=c(0:23))
axis(side=2, at=seq(0, 600, by=100))
box()

What do the python file extensions, .pyc .pyd .pyo stand for?

  • .py - Regular script
  • .py3 - (rarely used) Python3 script. Python3 scripts usually end with ".py" not ".py3", but I have seen that a few times
  • .pyc - compiled script (Bytecode)
  • .pyo - optimized pyc file (As of Python3.5, Python will only use pyc rather than pyo and pyc)
  • .pyw - Python script to run in Windowed mode, without a console; executed with pythonw.exe
  • .pyx - Cython src to be converted to C/C++
  • .pyd - Python script made as a Windows DLL
  • .pxd - Cython script which is equivalent to a C/C++ header
  • .pxi - MyPy stub
  • .pyi - Stub file (PEP 484)
  • .pyz - Python script archive (PEP 441); this is a script containing compressed Python scripts (ZIP) in binary form after the standard Python script header
  • .pywz - Python script archive for MS-Windows (PEP 441); this is a script containing compressed Python scripts (ZIP) in binary form after the standard Python script header
  • .py[cod] - wildcard notation in ".gitignore" that means the file may be ".pyc", ".pyo", or ".pyd".
  • .pth - a path configuration file; its contents are additional items (one per line) to be added to sys.path. See site module.

A larger list of additional Python file-extensions (mostly rare and unofficial) can be found at http://dcjtech.info/topic/python-file-extensions/

Excel: replace part of cell's string value

what you're looking for is SUBSTITUTE:

=SUBSTITUTE(A2,"Author","Authoring")

Will substitute Author for Authoring without messing with everything else

File upload progress bar with jQuery

If you are using jquery on your project, and do not want to implement the upload mechanism from scratch, you can use https://github.com/blueimp/jQuery-File-Upload.

They have a very nice api with multiple file selection, drag&drop support, progress bar, validation and preview images, cross-domain support, chunked and resumable file uploads. And they have sample scripts for multiple server languages(node, php, python and go).

Demo url: https://blueimp.github.io/jQuery-File-Upload/.

Google Maps: How to create a custom InfoWindow?

I'm not sure how FWIX.com is doing it specifically, but I'd wager they are using Custom Overlays.

How To Change DataType of a DataColumn in a DataTable?

I've taken a bit of a different approach. I needed to parse a datetime from an excel import that was in the OA date format. This methodology is simple enough to build from... in essence,

  1. Add column of type you want
  2. Rip through the rows converting the value
  3. Delete the original column and rename to the new to match the old

    private void ChangeColumnType(System.Data.DataTable dt, string p, Type type){
            dt.Columns.Add(p + "_new", type);
            foreach (System.Data.DataRow dr in dt.Rows)
            {   // Will need switch Case for others if Date is not the only one.
                dr[p + "_new"] =DateTime.FromOADate(double.Parse(dr[p].ToString())); // dr[p].ToString();
            }
            dt.Columns.Remove(p);
            dt.Columns[p + "_new"].ColumnName = p;
        }
    

Oracle: not a valid month

You can also change the value of this database parameter for your session by using the ALTER SESSION command and use it as you wanted

ALTER SESSION SET NLS_DATE_FORMAT = 'DD-MM-YYYY';
SELECT TO_DATE('05-12-2015') FROM dual;

05/12/2015

Jquery get form field value

_x000D_
_x000D_
$("form").submit(function(event) {_x000D_
    _x000D_
      var firstfield_value  = event.currentTarget[0].value;_x000D_
     _x000D_
      var secondfield_value = event.currentTarget[1].value; _x000D_
     _x000D_
      alert(firstfield_value);_x000D_
      alert(secondfield_value);_x000D_
      event.preventDefault(); _x000D_
     });
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<form action="" method="post" >_x000D_
<input type="text" name="field1" value="value1">_x000D_
<input type="text" name="field2" value="value2">_x000D_
</form>
_x000D_
_x000D_
_x000D_

How to check whether a int is not null or empty?

I think you are asking about code like this.

int  count = (request.getParameter("counter") == null) ? 0 : Integer.parseInt(request.getParameter("counter"));

Simulate low network connectivity for Android

  1. Open terminal inAndroid Studio and Go to ../../Android/sdk/tools. 'emulator' executable should be available here.

  2. Run ./emulator -netdelay "delay_in_millis" -avd "emulator_device_name"

    Ex: ./emulator -netdelay 60000 -avd Nexus_5_API_21

  3. Now build your app and install it in emulator.

  4. Run your scenario in app.

Make sure you have your code changes in app that sets timeout to your request and handles that.

How to execute a * .PY file from a * .IPYNB file on the Jupyter notebook?

the below lines would also work

!python script.py

How can I get city name from a latitude and longitude point?

In node.js we can use node-geocoder npm module to get address from lat, lng.,

geo.js

var NodeGeocoder = require('node-geocoder');

var options = {
  provider: 'google',
  httpAdapter: 'https', // Default
  apiKey: ' ', // for Mapquest, OpenCage, Google Premier
  formatter: 'json' // 'gpx', 'string', ...
};

var geocoder = NodeGeocoder(options);

geocoder.reverse({lat:28.5967439, lon:77.3285038}, function(err, res) {
  console.log(res);
});

output:

node geo.js

[ { formattedAddress: 'C-85B, C Block, Sector 8, Noida, Uttar Pradesh 201301, India',
    latitude: 28.5967439,
    longitude: 77.3285038,
    extra: 
     { googlePlaceId: 'ChIJkTdx9vzkDDkRx6LVvtz1Rhk',
       confidence: 1,
       premise: 'C-85B',
       subpremise: null,
       neighborhood: 'C Block',
       establishment: null },
    administrativeLevels: 
     { level2long: 'Gautam Buddh Nagar',
       level2short: 'Gautam Buddh Nagar',
       level1long: 'Uttar Pradesh',
       level1short: 'UP' },
    city: 'Noida',
    country: 'India',
    countryCode: 'IN',
    zipcode: '201301',
    provider: 'google' } ]

react hooks useEffect() cleanup for only componentWillUnmount?

you can use more than one useEffect

for example if my variable is data1 i can use all of this in my component

useEffect( () => console.log("mount"), [] );
useEffect( () => console.log("will update data1"), [ data1 ] );
useEffect( () => console.log("will update any") );
useEffect( () => () => console.log("will update data1 or unmount"), [ data1 ] );
useEffect( () => () => console.log("unmount"), [] );

Bootstrap onClick button event

If, like me, you had dynamically created buttons on your page, the

$("#your-bs-button's-id").on("click", function(event) {
                       or
$(".your-bs-button's-class").on("click", function(event) {

methods won't work because they only work on current elements (not future elements). Instead you need to reference a parent item that existed at the initial loading of the web page.

$(document).on("click", "#your-bs-button's-id", function(event) {
                       or more generally
$("#pre-existing-element-id").on("click", ".your-bs-button's-class", function(event) {

There are many other references to this issue on stack overflow here and here.

Converting Date and Time To Unix Timestamp

You can use Date.getTime() function, or the Date object itself which when divided returns the time in milliseconds.

var d = new Date();

d/1000
> 1510329641.84

d.getTime()/1000
> 1510329641.84

Run php script as daemon process

You can

  1. Use nohup as Henrik suggested.
  2. Use screen and run your PHP program as a regular process inside that. This gives you more control than using nohup.
  3. Use a daemoniser like http://supervisord.org/ (it's written in Python but can daemonise any command line program and give you a remote control to manage it).
  4. Write your own daemonise wrapper like Emil suggested but it's overkill IMO.

I'd recommend the simplest method (screen in my opinion) and then if you want more features or functionality, move to more complex methods.

How to solve SyntaxError on autogenerated manage.py?

It seems you have more than one version of Python on your computer. Try and remove one and leave the only version you used to develop your application.

If need be, you can upgrade your version, but ensure you have only one version of Python on your computer.

I hope this helps.

SQL to Query text in access with an apostrophe in it

...better is declare the name as varible ,and ask before if thereis a apostrophe in the string:

e.g.:

DIM YourName string

YourName = "Daniel O'Neal"

  If InStr(YourName, "'") Then
      SELECT * FROM tblStudents WHERE [name]  Like """ Your Name """ ;
   else
      SELECT * FROM tblStudents WHERE [name] Like '" Your Name "' ;       
  endif

Do conditional INSERT with SQL?

It is possible with EXISTS condition. WHERE EXISTS tests for the existence of any records in a subquery. EXISTS returns true if the subquery returns one or more records. Here is an example

UPDATE  TABLE_NAME 
SET val1=arg1 , val2=arg2
WHERE NOT EXISTS
    (SELECT FROM TABLE_NAME WHERE val1=arg1 AND val2=arg2)

With form validation: why onsubmit="return functionname()" instead of onsubmit="functionname()"?

You need the return so the true/false gets passed up to the form's submit event (which looks for this and prevents submission if it gets a false).

Lets look at some standard JS:

function testReturn() { return false; }

If you just call that within any other code (be it an onclick handler or in JS elsewhere) it will get back false, but you need to do something with that value.

...
testReturn()
...

In that example the return value is coming back, but nothing is happening with it. You're basically saying execute this function, and I don't care what it returns. In contrast if you do this:

...
var wasSuccessful = testReturn();
...

then you've done something with the return value.

The same applies to onclick handlers. If you just call the function without the return in the onsubmit, then you're saying "execute this, but don't prevent the event if it return false." It's a way of saying execute this code when the form is submitted, but don't let it stop the event.

Once you add the return, you're saying that what you're calling should determine if the event (submit) should continue.

This logic applies to many of the onXXXX events in HTML (onclick, onsubmit, onfocus, etc).

Sending data back to the Main Activity in Android

Call the child activity Intent using the startActivityForResult() method call

There is an example of this here: http://developer.android.com/training/notepad/notepad-ex2.html

and in the "Returning a Result from a Screen" of this: http://developer.android.com/guide/faq/commontasks.html#opennewscreen

List submodules in a Git repository

In my version of Git [1], every Git submodule has a name and a path. They don't necessarily have to be the same [2]. Getting both in a reliable way, without checking out the submodules first (git update --init), is a tricky bit of shell wizardry.

Get a list of submodule names

I didn't find a way how to achieve this using git config or any other git command. Therefore we are back to regex on .gitmodules (super ugly). But it seems to be somewhat safe since git limits the possible code space allowed for submodule names. In addition, since you probably want to use this list for further shell processing, the solution below separate entries with NULL-bytes (\0).

$ sed -nre \
  's/^\[submodule \"(.*)\"]$/\1\x0/p' \
  "$(git rev-parse --show-toplevel)/.gitmodules" \
| tr -d '\n' \
| xargs -0 -n1 printf "%b\0"

And in your script:

#!/usr/bin/env bash

while IFS= read -rd '' submodule_name; do
  echo submodule name: "${submodule_name}"
done < <(
  sed -nre \
    's/^\[submodule \"(.*)\"]$/\1\x0/p' \
    "$(git rev-parse --show-toplevel)/.gitmodules" \
  | tr -d '\n' \
  | xargs -0 -n1 printf "%b\0"
)

Note: read -rd '' requires bash and won't work with sh.

Get a list of submodule paths

In my approach I try not to process the output from git config --get-regexp with awk, tr, sed, ... but instead pass it a zero byte separated back to git config --get. This is to avoid problems with newlines, spaces and other special characters (e.g. Unicode) in the submodule paths. In addition, since you probably want to use this list for further shell processing, the solution below separate entries with NULL-bytes (\0).

$ git config --null --file .gitmodules --name-only --get-regexp '\.path$' \
| xargs -0 -n1 git config --null --file .gitmodules --get

For example, in a Bash script you could then:

#!/usr/bin/env bash

while IFS= read -rd '' submodule_path; do
  echo submodule path: "${submodule_path}"
done < <(
  git config --null --file .gitmodules --name-only --get-regexp '\.path$' \
  | xargs -0 -n1 git config --null --file .gitmodules --get
)

Note: read -rd '' requires bash and won't work with sh.


Footnotes

[1] Git version

$ git --version
git version 2.22.0

[2] Submodule with diverging name and path

Set up test repository:

$ git init test-name-path
$ cd test-name-path/
$ git checkout -b master
$ git commit --allow-empty -m 'test'
$ git submodule add ./ submodule-name
Cloning into '/tmp/test-name-path/submodule-name'...
done.
$ ls
submodule-name

$ cat .gitmodules
[submodule "submodule-name"]
    path = submodule-name
    url = ./

Move submodule to make name and path diverge:

$ git mv submodule-name/ submodule-path

$ ls
submodule-path

$ cat .gitmodules
[submodule "submodule-name"]
    path = submodule-path
    url = ./

$ git config --file .gitmodules --get-regexp '\.path$'
submodule.submodule-name.path submodule-path

Testing

Set up test repository:

$ git init test
$ cd test/
$ git checkout -b master
$ git commit --allow-empty -m 'test'
$
$ git submodule add ./ simplename
Cloning into '/tmp/test/simplename'...
done.
$
$ git submodule add ./ 'name with spaces'
Cloning into '/tmp/test/name with spaces'...
done.
$
$ git submodule add ./ 'future-name-with-newlines'
Cloning into '/tmp/test/future-name-with-newlines'...
done.
$ git mv future-name-with-newlines/ 'name
> with
> newlines'
$
$ git submodule add ./ 'name-with-unicode-'
Cloning into '/tmp/test/name-with-unicode-'...
done.
$
$ git submodule add ./ sub/folder/submodule
Cloning into '/tmp/test/sub/folder/submodule'...
done.
$
$ git submodule add ./ name.with.dots
Cloning into '/tmp/test/name.with.dots'...
done.
$
$ git submodule add ./ 'name"with"double"quotes'
Cloning into '/tmp/test/name"with"double"quotes'...
done.
$
$ git submodule add ./ "name'with'single'quotes"
Cloning into '/tmp/test/name'with'single'quotes''...
done.
$ git submodule add ./ 'name]with[brackets'
Cloning into '/tmp/test/name]with[brackets'...
done.
$ git submodule add ./ 'name-with-.path'
Cloning into '/tmp/test/name-with-.path'...
done.

.gitmodules:

[submodule "simplename"]
    path = simplename
    url = ./
[submodule "name with spaces"]
    path = name with spaces
    url = ./
[submodule "future-name-with-newlines"]
    path = name\nwith\nnewlines
    url = ./
[submodule "name-with-unicode-"]
    path = name-with-unicode-
    url = ./
[submodule "sub/folder/submodule"]
    path = sub/folder/submodule
    url = ./
[submodule "name.with.dots"]
    path = name.with.dots
    url = ./
[submodule "name\"with\"double\"quotes"]
    path = name\"with\"double\"quotes
    url = ./
[submodule "name'with'single'quotes"]
    path = name'with'single'quotes
    url = ./
[submodule "name]with[brackets"]
    path = name]with[brackets
    url = ./
[submodule "name-with-.path"]
    path = name-with-.path
    url = ./

Get list of submodule names

$ sed -nre \
  's/^\[submodule \"(.*)\"]$/\1\x0/p' \
  "$(git rev-parse --show-toplevel)/.gitmodules" \
| tr -d '\n' \
| xargs -0 -n1 printf "%b\0" \
| xargs -0 -n1 echo submodule name:
submodule name: simplename
submodule name: name with spaces
submodule name: future-name-with-newlines
submodule name: name-with-unicode-
submodule name: sub/folder/submodule
submodule name: name.with.dots
submodule name: name"with"double"quotes
submodule name: name'with'single'quotes
submodule name: name]with[brackets
submodule name: name-with-.path

Get list of submodule paths

$ git config --null --file .gitmodules --name-only --get-regexp '\.path$' \
| xargs -0 -n1 git config --null --file .gitmodules --get \
| xargs -0 -n1 echo submodule path:
submodule path: simplename
submodule path: name with spaces
submodule path: name
with
newlines
submodule path: name-with-unicode-
submodule path: sub/folder/submodule
submodule path: name.with.dots
submodule path: name"with"double"quotes
submodule path: name'with'single'quotes
submodule path: name]with[brackets
submodule path: name-with-.path

How to create a POJO?

When you aren't doing anything to make your class particularly designed to work with a given framework, ORM, or other system that needs a special sort of class, you have a Plain Old Java Object, or POJO.

Ironically, one of the reasons for coining the term is that people were avoiding them in cases where they were sensible and some people concluded that this was because they didn't have a fancy name. Ironic, because your question demonstrates that the approach worked.

Compare the older POD "Plain Old Data" to mean a C++ class that doesn't do anything a C struct couldn't do (more or less, non-virtual members that aren't destructors or trivial constructors don't stop it being considered POD), and the newer (and more directly comparable) POCO "Plain Old CLR Object" in .NET.

Failed to Connect to MySQL at localhost:3306 with user root

It worked for me this way:

Step1: Open System Preference > MySQL > Initialize Database.

Step2: Put password you used while installing MySQL.

Step3: Start MySQL server.

Step4: Come back to MySQL Workbench and double connect/ create a new one.

How to perform a sum of an int[] array

Once is out (March 2014) you'll be able to use streams:

int sum = IntStream.of(a).sum();

or even

int sum = IntStream.of(a).parallel().sum();

SVG gradient using CSS

Thank you everyone, for all your precise replys.

Using the svg in a shadow dom, I add the 3 linear gradients I need within the svg, inside a . I place the css fill rule on the web component and the inheritance od fill does the job.

_x000D_
_x000D_
    <svg viewbox="0 0 512 512" xmlns="http://www.w3.org/2000/svg">
      <path
        d="m258 0c-45 0-83 38-83 83 0 45 37 83 83 83 45 0 83-39 83-84 0-45-38-82-83-82zm-85 204c-13 0-24 10-24 23v48c0 13 11 23 24 23h23v119h-23c-13 0-24 11-24 24l-0 47c0 13 11 24 24 24h168c13 0 24-11 24-24l0-47c0-13-11-24-24-24h-21v-190c0-13-11-23-24-23h-123z"></path>
    </svg>
    
    <svg height="0" width="0">
      <defs>
        <linearGradient id="lgrad-p" gradientTransform="rotate(75)"><stop offset="45%" stop-color="#4169e1"></stop><stop offset="99%" stop-color="#c44764"></stop></linearGradient>
        <linearGradient id="lgrad-s" gradientTransform="rotate(75)"><stop offset="45%" stop-color="#ef3c3a"></stop><stop offset="99%" stop-color="#6d5eb7"></stop></linearGradient>
        <linearGradient id="lgrad-g" gradientTransform="rotate(75)"><stop offset="45%" stop-color="#585f74"></stop><stop offset="99%" stop-color="#b6bbc8"></stop></linearGradient>
      </defs>
    </svg>
    
    <div></div>

    <style>
      :first-child {
        height:150px;
        width:150px;
        fill:url(#lgrad-p) blue;
      }
      div{
        position:relative;
        width:150px;
        height:150px;
        fill:url(#lgrad-s) red;
      }
    </style>
    <script>
      const shadow = document.querySelector('div').attachShadow({mode: 'open'});
      shadow.innerHTML="<svg viewbox=\"0 0 512 512\">\
        <path d=\"m258 0c-45 0-83 38-83 83 0 45 37 83 83 83 45 0 83-39 83-84 0-45-38-82-83-82zm-85 204c-13 0-24 10-24 23v48c0 13 11 23 24 23h23v119h-23c-13 0-24 11-24 24l-0 47c0 13 11 24 24 24h168c13 0 24-11 24-24l0-47c0-13-11-24-24-24h-21v-190c0-13-11-23-24-23h-123z\"></path>\
      </svg>\
      <svg height=\"0\">\
      <defs>\
        <linearGradient id=\"lgrad-s\" gradientTransform=\"rotate(75)\"><stop offset=\"45%\" stop-color=\"#ef3c3a\"></stop><stop offset=\"99%\" stop-color=\"#6d5eb7\"></stop></linearGradient>\
        <linearGradient id=\"lgrad-g\" gradientTransform=\"rotate(75)\"><stop offset=\"45%\" stop-color=\"#585f74\"></stop><stop offset=\"99%\" stop-color=\"#b6bbc8\"></stop></linearGradient>\
      </defs>\
    </svg>\
    ";
    </script>
_x000D_
_x000D_
_x000D_

The first one is normal SVG, the second one is inside a shadow dom.

Correct use for angular-translate in controllers

EDIT: Please see the answer from PascalPrecht (the author of angular-translate) for a better solution.


The asynchronous nature of the loading causes the problem. You see, with {{ pageTitle | translate }}, Angular will watch the expression; when the localization data is loaded, the value of the expression changes and the screen is updated.

So, you can do that yourself:

.controller('FirstPageCtrl', ['$scope', '$filter', function ($scope, $filter) {
    $scope.$watch(
        function() { return $filter('translate')('HELLO_WORLD'); },
        function(newval) { $scope.pageTitle = newval; }
    );
});

However, this will run the watched expression on every digest cycle. This is suboptimal and may or may not cause a visible performance degradation. Anyway it is what Angular does, so it cant be that bad...

Singleton design pattern vs Singleton beans in Spring container

Spring singleton bean is described as 'per container per bean'. Singleton scope in Spring means that same object at same memory location will be returned to same bean id. If one creates multiple beans of different ids of the same class then container will return different objects to different ids. This is like a key value mapping where key is bean id and value is the bean object in one spring container. Where as Singleton pattern ensures that one and only one instance of a particular class will ever be created per classloader.

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

I got the same message ("repository element was not specified in the POM inside distributionManagement element"). I checked /target/checkout/pom.xml and as per another answer and it really lacked <distributionManagement>.

It turned out that the problem was that <distributionManagement> was missing in pom.xml in my master branch (using git).

After cleaning up (mvn release:rollback, mvn clean, mvn release:clean, git tag -d v1.0.0) I run mvn release again and it worked.

What's better at freeing memory with PHP: unset() or $var = null

PHP 7 is already worked on such memory management issues and its reduced up-to minimal usage.

<?php
  $start = microtime(true);
  for ($i = 0; $i < 10000000; $i++) {
    $a = 'a';
    $a = NULL;
  }
  $elapsed = microtime(true) - $start;

  echo "took $elapsed seconds\r\n";

  $start = microtime(true);
  for ($i = 0; $i < 10000000; $i++) {
     $a = 'a';
     unset($a);
  }
  $elapsed = microtime(true) - $start;

  echo "took $elapsed seconds\r\n";

?>

PHP 7.1 Outpu:

took 0.16778993606567 seconds took 0.16630101203918 seconds

Query for array elements inside JSON type

jsonb in Postgres 9.4+

You can use the same query as below, just with jsonb_array_elements().

But rather use the jsonb "contains" operator @> in combination with a matching GIN index on the expression data->'objects':

CREATE INDEX reports_data_gin_idx ON reports
USING gin ((data->'objects') jsonb_path_ops);

SELECT * FROM reports WHERE data->'objects' @> '[{"src":"foo.png"}]';

Since the key objects holds a JSON array, we need to match the structure in the search term and wrap the array element into square brackets, too. Drop the array brackets when searching a plain record.

More explanation and options:

json in Postgres 9.3+

Unnest the JSON array with the function json_array_elements() in a lateral join in the FROM clause and test for its elements:

SELECT data::text, obj
FROM   reports r, json_array_elements(r.data#>'{objects}') obj
WHERE  obj->>'src' = 'foo.png';

db<>fiddle here
Old sqlfiddle

The CTE (WITH query) just substitutes for a table reports.
Or, equivalent for just a single level of nesting:

SELECT *
FROM   reports r, json_array_elements(r.data->'objects') obj
WHERE  obj->>'src' = 'foo.png';

->>, -> and #> operators are explained in the manual.

Both queries use an implicit JOIN LATERAL.

Closely related:

Convert Java Object to JsonNode in Jackson

As of Jackson 1.6, you can use:

JsonNode node = mapper.valueToTree(map);

or

JsonNode node = mapper.convertValue(object, JsonNode.class);

Source: is there a way to serialize pojo's directly to treemodel?

How to set Meld as git mergetool

It took a few permutations to get meld working on windows for me. This is my current .gitconfig:

[merge]
    conflictstyle = diff3
    tool = meld
[mergetool "meld"]
    cmd = \"C:\\Program Files (x86)\\Meld\\Meld.exe\" --auto-merge \"$LOCAL\" \"$BASE\" \"$REMOTE\" --output \"$MERGED\"

Linux:

[merge]
    conflictstyle = diff3
    tool = meld
[mergetool "meld"]
    cmd = meld --auto-merge $LOCAL $BASE $REMOTE --output=$MERGED --diff $BASE $LOCAL --diff $BASE $REMOTE

I believe adding conflictstyle = diff3 changes the inline text to include BASE contents in the output file before meld gets to it, which might give it a head start. Not sure.

Now, since I already noted Meld supports three-way merging, there is another option. When “diff3” git conflict style is set, Meld prints “(??)” on the line showing the content from BASE. source

A few meld command line features I really like:

  • --auto-merge does a great job at choosing the right thing for you (it's not bulletproof, but I consider the time saved to be worth any risk).

  • You can add extra diff windows in the same command. E.g.:

    --diff $BASE $LOCAL --diff $BASE $REMOTE

    will add two more tabs with the local and incoming patch diffs. These can be quite useful to see separately from the 3 way view to see separate diffs from the base in each branch. I could't get this working on windows though.

  • Some version of meld allow you to label tabs with --label. This was more important before git fixed the names of the files passed to meld to include local/base/remote.

  • The order of --diff can affect the tab order. I had trouble in some older versions that were putting the additional diffs first, when the main 3 way diff is far more frequently used.

How do you use $sce.trustAsHtml(string) to replicate ng-bind-html-unsafe in Angular 1.2+

For Rails (at least in my case) if you are using the angularjs-rails gem, please remember to add the sanitize module

//= require angular
//= require angular-sanitize

And then load it up in your app...

var myDummyApp = angular.module('myDummyApp', ['ngSanitize']);

Then you can do the following:

On the template:

%span{"ng-bind-html"=>"phone_with_break(x)"}

And eventually:

$scope.phone_with_break = function (x) {
  if (x.phone != "") {
   return x.phone + "<br>";
  }
  return '';
}

continuous page numbering through section breaks

You can check out this post on SuperUser.

Word starts page numbering over for each new section by default.

I do it slightly differently than the post above that goes through the ribbon menus, but in both methods you have to go through the document to each section's beginning.

My method:

  • open up the footer (or header if that's where your page number is)
  • drag-select the page number
  • right-click on it
  • hit Format Page Numbers
  • click on the Continue from Previous Section radio button under Page numbering

I find this right-click method to be a little faster. Also, usually if I insert the page numbers first before I start making any new sections, this problem doesn't happen in the first place.

Salt and hash a password in Python

As of Python 3.4, the hashlib module in the standard library contains key derivation functions which are "designed for secure password hashing".

So use one of those, like hashlib.pbkdf2_hmac, with a salt generated using os.urandom:

from typing import Tuple
import os
import hashlib
import hmac

def hash_new_password(password: str) -> Tuple[bytes, bytes]:
    """
    Hash the provided password with a randomly-generated salt and return the
    salt and hash to store in the database.
    """
    salt = os.urandom(16)
    pw_hash = hashlib.pbkdf2_hmac('sha256', password.encode(), salt, 100000)
    return salt, pw_hash

def is_correct_password(salt: bytes, pw_hash: bytes, password: str) -> bool:
    """
    Given a previously-stored salt and hash, and a password provided by a user
    trying to log in, check whether the password is correct.
    """
    return hmac.compare_digest(
        pw_hash,
        hashlib.pbkdf2_hmac('sha256', password.encode(), salt, 100000)
    )

# Example usage:
salt, pw_hash = hash_new_password('correct horse battery staple')
assert is_correct_password(salt, pw_hash, 'correct horse battery staple')
assert not is_correct_password(salt, pw_hash, 'Tr0ub4dor&3')
assert not is_correct_password(salt, pw_hash, 'rosebud')

Note that:

  • The use of a 16-byte salt and 100000 iterations of PBKDF2 match the minimum numbers recommended in the Python docs. Further increasing the number of iterations will make your hashes slower to compute, and therefore more secure.
  • os.urandom always uses a cryptographically secure source of randomness
  • hmac.compare_digest, used in is_correct_password, is basically just the == operator for strings but without the ability to short-circuit, which makes it immune to timing attacks. That probably doesn't really provide any extra security value, but it doesn't hurt, either, so I've gone ahead and used it.

For theory on what makes a good password hash and a list of other functions appropriate for hashing passwords with, see https://security.stackexchange.com/q/211/29805.

Module AppRegistry is not registered callable module (calling runApplication)

What worked for me was to just stop the node server running and run 'react-native run-ios' once again

xlrd.biffh.XLRDError: Excel xlsx file; not supported

As noted in the release email, linked to from the release tweet and noted in large orange warning that appears on the front page of the documentation, and less orange, but still present, in the readme on the repository and the release on pypi:

xlrd has explicitly removed support for anything other than xls files.

In your case, the solution is to:

  • make sure you are on a recent version of Pandas, at least 1.0.1, and preferably the latest release. 1.2 will make his even clearer.
  • install openpyxl: https://openpyxl.readthedocs.io/en/stable/
  • change your Pandas code to be:
    df1 = pd.read_excel(
         os.path.join(APP_PATH, "Data", "aug_latest.xlsm"),
         engine='openpyxl',
    )
    

Remove directory from remote repository after adding them to .gitignore

Note: This solution works only with Github Desktop GUI.

By using Github Desktop GUI it is very simple.

  1. Move the folder onto another location (to out of the project folder) temporarily.

  2. Edit your .gitignore file and remove the folder entry which would be remove master repository on the github page.

  3. Commit and Sync the project folder.

  4. Re-move the folder into the project folder

  5. Re-edit .gitignore file.

That's all.

Location of the android sdk has not been setup in the preferences in mac os?

Hi try this in eclipse: Window - Preferences - Android - SDK Location and setup SDK path.

How to Avoid Response.End() "Thread was being aborted" Exception during the Excel file download

Looks to be the same question as:

When an ASP.NET System.Web.HttpResponse.End() is called, the current thread is aborted?

So it's by design. You need to add a catch for that exception and gracefully "ignore" it.

Change Title of Javascript Alert

You can't. The alert is a simple popup where you only can affect the content text.

If you want to change anything else, you have to use a different way of creating a popup.

How to use the toString method in Java?

From the Object.toString docs:

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

getClass().getName() + '@' + Integer.toHexString(hashCode())

Example:

String[] mystr ={"a","b","c"};
System.out.println("mystr.toString: " + mystr.toString());

output:- mystr.toString: [Ljava.lang.String;@13aaa14a

Class has no initializers Swift

You have to use implicitly unwrapped optionals so that Swift can cope with circular dependencies (parent <-> child of the UI components in this case) during the initialization phase.

@IBOutlet var imgBook: UIImageView!
@IBOutlet var titleBook: UILabel!
@IBOutlet var pageBook: UILabel!

Read this doc, they explain it all nicely.

How do I replace a character in a string in Java?

You may also want to check to make sure your not replacing an occurrence that has already been replaced. You can use a regular expression with negative lookahead to do this.

For example:

String str = "sdasdasa&amp;adas&dasdasa";  
str = str.replaceAll("&(?!amp;)", "&amp;");

This would result in the string "sdasdasa&amp;adas&amp;dasdasa".

The regex pattern "&(?!amp;)" basically says: Match any occurrence of '&' that is not followed by 'amp;'.

substring index range

public String substring(int beginIndex, int endIndex)

beginIndex—the begin index, inclusive.

endIndex—the end index, exclusive.

Example:

public class Test {

    public static void main(String args[]) {
        String Str = new String("Hello World");

        System.out.println(Str.substring(3, 8));
    }
 }

Output: "lo Wo"

From 3 to 7 index.

Also there is another kind of substring() method:

public String substring(int beginIndex)

beginIndex—the begin index, inclusive. Returns a sub string starting from beginIndex to the end of the main String.

Example:

public class Test {

    public static void main(String args[]) {
        String Str = new String("Hello World");

        System.out.println(Str.substring(3));
    }
}

Output: "lo World"

From 3 to the last index.

Press Keyboard keys using a batch file

Wow! Mean this that you must learn a different programming language just to send two keys to the keyboard? There are simpler ways for you to achieve the same thing. :-)

The Batch file below is an example that start another program (cmd.exe in this case), send a command to it and then send an Up Arrow key, that cause to recover the last executed command. The Batch file is simple enough to be understand with no problems, so you may modify it to fit your needs.

@if (@CodeSection == @Batch) @then


@echo off

rem Use %SendKeys% to send keys to the keyboard buffer
set SendKeys=CScript //nologo //E:JScript "%~F0"

rem Start the other program in the same Window
start "" /B cmd

%SendKeys% "echo off{ENTER}"

set /P "=Wait and send a command: " < NUL
ping -n 5 -w 1 127.0.0.1 > NUL
%SendKeys% "echo Hello, world!{ENTER}"

set /P "=Wait and send an Up Arrow key: [" < NUL
ping -n 5 -w 1 127.0.0.1 > NUL
%SendKeys% "{UP}"

set /P "=] Wait and send an Enter key:" < NUL
ping -n 5 -w 1 127.0.0.1 > NUL
%SendKeys% "{ENTER}"

%SendKeys% "exit{ENTER}"

goto :EOF


@end


// JScript section

var WshShell = WScript.CreateObject("WScript.Shell");
WshShell.SendKeys(WScript.Arguments(0));

For a list of key names for SendKeys, see: http://msdn.microsoft.com/en-us/library/8c6yea83(v=vs.84).aspx

For example:

LEFT ARROW    {LEFT}
RIGHT ARROW   {RIGHT}

For a further explanation of this solution, see: GnuWin32 openssl s_client conn to WebSphere MQ server not closing at EOF, hangs

What is callback in Android?

CallBack Interface are used for Fragment to Fragment communication in android.

Refer here for your understanding.

How to select an element with 2 classes

Just chain them together:

.a.b {
  color: #666;
}

How to create a JSON object

Usually, you would do something like this:

$post_data = json_encode(array('item' => $post_data));

But, as it seems you want the output to be with "{}", you better make sure to force json_encode() to encode as object, by passing the JSON_FORCE_OBJECT constant.

$post_data = json_encode(array('item' => $post_data), JSON_FORCE_OBJECT);

"{}" brackets specify an object and "[]" are used for arrays according to JSON specification.

Simple way to change the position of UIView?

@TomSwift Swift 3 answer

aView.center = CGPoint(x: 150, y: 150); // set center

Or

aView.frame = CGRect(x: 100, y: 200, width: aView.frame.size.width, height: aView.frame.size.height ); // set new position exactly

Or

aView.frame = aView.frame.offsetBy(dx: CGFloat(10), dy: CGFloat(10)) // offset by an amount

How to use the read command in Bash?

Another alternative altogether is to use the printf function.

printf -v str 'hello'

Moreover, this construct, combined with the use of single quotes where appropriate, helps to avoid the multi-escape problems of subshells and other forms of interpolative quoting.

Return Bit Value as 1/0 and NOT True/False in SQL Server

just you pass this things in your select query. using CASE

CASE WHEN  gender=0 then 'Female' WHEN  gender=1 then 'Male' END as Genderdisp

Writing files in Node.js

You can use library easy-file-manager

install first from npm npm install easy-file-manager

Sample to upload and remove files

var filemanager = require('easy-file-manager')
var path = "/public"
var filename = "test.jpg"
var data; // buffered image

filemanager.upload(path,filename,data,function(err){
    if (err) console.log(err);
});

filemanager.remove(path,"aa,filename,function(isSuccess){
    if (err) console.log(err);
});

What is the difference between __str__ and __repr__?

>>> print(decimal.Decimal(23) / decimal.Decimal("1.05"))
21.90476190476190476190476190
>>> decimal.Decimal(23) / decimal.Decimal("1.05")
Decimal('21.90476190476190476190476190')

When print() is called on the result of decimal.Decimal(23) / decimal.Decimal("1.05") the raw number is printed; this output is in string form which can be achieved with __str__(). If we simply enter the expression we get a decimal.Decimal output — this output is in representational form which can be achieved with __repr__(). All Python objects have two output forms. String form is designed to be human-readable. The representational form is designed to produce output that if fed to a Python interpreter would (when possible) reproduce the represented object.

S3 limit to objects in a bucket

It looks like the limit has changed. You can store 5TB for a single object.

The total volume of data and number of objects you can store are unlimited. Individual Amazon S3 objects can range in size from a minimum of 0 bytes to a maximum of 5 terabytes. The largest object that can be uploaded in a single PUT is 5 gigabytes. For objects larger than 100 megabytes, customers should consider using the Multipart Upload capability.

http://aws.amazon.com/s3/faqs/#How_much_data_can_I_store

How can I use external JARs in an Android project?

If you are using gradle build system, follow these steps:

  1. put jar files inside respective libs folder of your android app. You will generally find it at Project > app > libs. If libs folder is missing, create one.

  2. add this to your build.gradle file your app. (Not to your Project's build.gradle)

    dependencies {
        compile fileTree(dir: 'libs', include: '*.jar')
        // other dependencies
    }
    

    This will include all your jar files available in libs folder.

If don't want to include all jar files, then you can add it individually.

compile fileTree(dir: 'libs', include: 'file.jar')

How do I copy directories recursively with gulp?

So - the solution of providing a base works given that all of the paths have the same base path. But if you want to provide different base paths, this still won't work.

One way I solved this problem was by making the beginning of the path relative. For your case:

gulp.src([
    'index.php',
    '*css/**/*',
    '*js/**/*',
    '*src/**/*',
])
.pipe(gulp.dest('/var/www/'));

The reason this works is that Gulp sets the base to be the end of the first explicit chunk - the leading * causes it to set the base at the cwd (which is the result that we all want!)

This only works if you can ensure your folder structure won't have certain paths that could match twice. For example, if you had randomjs/ at the same level as js, you would end up matching both.

This is the only way that I have found to include these as part of a top-level gulp.src function. It would likely be simple to create a plugin/function that could separate out each of those globs so you could specify the base directory for them, however.

Total number of items defined in an enum

If you find yourself writing the above solution as often as I do then you could implement it as a generic:

public static int GetEnumEntries<T>() where T : struct, IConvertible 
{
    if (!typeof(T).IsEnum)
        throw new ArgumentException("T must be an enumerated type");

    return Enum.GetNames(typeof(T)).Length;
}