Programs & Examples On #Web scraping

Web scraping is the process of extracting specific information from websites that do not readily provide an API or other methods of automated data retrieval. Questions about "How To Get Started With Scraping" (e.g. with Excel VBA) should be *thoroughly researched* as numerous functional code samples are available. Web scraping methods include 3rd-party applications, development of custom software, or even manual data collection in a standardized way.

How can I get the Google cache age of any URL or web page?

its too simple, you can just type "cache:" before the URL of the page. for example if you want to check the last webcache of this page simply type on URL bar cache:http://stackoverflow.com/questions/4560400/how-can-i-get-the-google-cache-age-of-any-url-or-web-page

this will show you the last webcache of the page.see here:

enter image description here

But remember, the caching of a webpage will only show if the page is already indexed on search engine(Google). for this you need to check the meta robot tag of that page.

What should I use to open a url instead of urlopen in urllib3

The new urllib3 library has a nice documentation here
In order to get your desired result you shuld follow that:

Import urllib3
from bs4 import BeautifulSoup

url = 'http://www.thefamouspeople.com/singers.php'

http = urllib3.PoolManager()
response = http.request('GET', url)
soup = BeautifulSoup(response.data.decode('utf-8'))

The "decode utf-8" part is optional. It worked without it when i tried, but i posted the option anyway.
Source: User Guide

How to use Python requests to fake a browser visit a.k.a and generate User Agent?

This is how, I have been using a random user agent from a list of nearlly 1000 fake user agents

from random_user_agent.user_agent import UserAgent
from random_user_agent.params import SoftwareName, OperatingSystem
software_names = [SoftwareName.ANDROID.value]
operating_systems = [OperatingSystem.WINDOWS.value, OperatingSystem.LINUX.value, OperatingSystem.MAC.value]   

user_agent_rotator = UserAgent(software_names=software_names, operating_systems=operating_systems, limit=1000)

# Get list of user agents.
user_agents = user_agent_rotator.get_user_agents()

user_agent_random = user_agent_rotator.get_random_user_agent()

Example

print(user_agent_random)

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36

For more details visit this link

Web scraping with Python

I use a combination of Scrapemark (finding urls - py2) and httlib2 (downloading images - py2+3). The scrapemark.py has 500 lines of code, but uses regular expressions, so it may be not so fast, did not test.

Example for scraping your website:

import sys
from pprint import pprint
from scrapemark import scrape

pprint(scrape("""
    <table class="spad">
        <tbody>
            {*
                <tr>
                    <td>{{[].day}}</td>
                    <td>{{[].sunrise}}</td>
                    <td>{{[].sunset}}</td>
                    {# ... #}
                </tr>
            *}
        </tbody>
    </table>
""", url=sys.argv[1] ))

Usage:

python2 sunscraper.py http://www.example.com/

Result:

[{'day': u'1. Dez 2012', 'sunrise': u'08:18', 'sunset': u'16:10'},
 {'day': u'2. Dez 2012', 'sunrise': u'08:19', 'sunset': u'16:10'},
 {'day': u'3. Dez 2012', 'sunrise': u'08:21', 'sunset': u'16:09'},
 {'day': u'4. Dez 2012', 'sunrise': u'08:22', 'sunset': u'16:09'},
 {'day': u'5. Dez 2012', 'sunrise': u'08:23', 'sunset': u'16:08'},
 {'day': u'6. Dez 2012', 'sunrise': u'08:25', 'sunset': u'16:08'},
 {'day': u'7. Dez 2012', 'sunrise': u'08:26', 'sunset': u'16:07'}]

How to find tag with particular text with Beautiful Soup?

A solution for finding a anchor tag if having a particular keyword would be the following:

from bs4 import BeautifulSoup
from urllib.request import urlopen,Request
from urllib.parse import urljoin,urlparse

rawLinks=soup.findAll('a',href=True)
for link in rawLinks:
    innercontent=link.text
    if keyword.lower() in innercontent.lower():
        print(link)

How to find elements by class

CSS selectors

single class first match

soup.select_one('.stylelistrow')

list of matches

soup.select('.stylelistrow')

compound class (i.e. AND another class)

soup.select_one('.stylelistrow.otherclassname')
soup.select('.stylelistrow.otherclassname')

Spaces in compound class names e.g. class = stylelistrow otherclassname are replaced with ".". You can continue to add classes.

list of classes (OR - match whichever present

soup.select_one('.stylelistrow, .otherclassname')
soup.select('.stylelistrow, .otherclassname')

bs4 4.7.1 +

Specific class whose innerText contains a string

soup.select_one('.stylelistrow:contains("some string")')
soup.select('.stylelistrow:contains("some string")')

Specific class which has a certain child element e.g. a tag

soup.select_one('.stylelistrow:has(a)')
soup.select('.stylelistrow:has(a)')

Scraping: SSL: CERTIFICATE_VERIFY_FAILED error for http://en.wikipedia.org

For novice users, you can go in the Applications folder and expand the Python 3.7 folder. Now first run (or double click) the Install Certificates.command and then Update Shell Profile.command

enter image description here

Use Excel VBA to click on a button in Internet Explorer, when the button has no "name" associated

IE.Document.getElementById("dgTime").getElementsByTagName("a")(0).Click

EDIT: to loop through the collection (items should appear in the same order as they are in the source document)

Dim links, link 

Set links = IE.Document.getElementById("dgTime").getElementsByTagName("a")

'For Each loop
For Each link in links
    link.Click
Next link

'For Next loop
Dim n, i
n = links.length
For i = 0 to n-1 Step 2
    links(i).click
Next I

How to "scan" a website (or page) for info, and bring it into my program?

Use a HTML parser like Jsoup. This has my preference above the other HTML parsers available in Java since it supports jQuery like CSS selectors. Also, its class representing a list of nodes, Elements, implements Iterable so that you can iterate over it in an enhanced for loop (so there's no need to hassle with verbose Node and NodeList like classes in the average Java DOM parser).

Here's a basic kickoff example (just put the latest Jsoup JAR file in classpath):

package com.stackoverflow.q2835505;

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

public class Test {

    public static void main(String[] args) throws Exception {
        String url = "https://stackoverflow.com/questions/2835505";
        Document document = Jsoup.connect(url).get();

        String question = document.select("#question .post-text").text();
        System.out.println("Question: " + question);

        Elements answerers = document.select("#answers .user-details a");
        for (Element answerer : answerers) {
            System.out.println("Answerer: " + answerer.text());
        }
    }

}

As you might have guessed, this prints your own question and the names of all answerers.

Is it ok to scrape data from Google results?

Google thrives on scraping websites of the world...so if it was "so illegal" then even Google won't survive ..of course other answers mention ways of mitigating IP blocks by Google. One more way to explore avoiding captcha could be scraping at random times (dint try) ..Moreover, I have a feeling, that if we provide novelty or some significant processing of data then it sounds fine at least to me...if we are simply copying a website.. or hampering its business/brand in some way...then it is bad and should be avoided..on top of it all...if you are a startup then no one will fight you as there is no benefit.. but if your entire premise is on scraping even when you are funded then you should think of more sophisticated ways...alternative APIs..eventually..Also Google keeps releasing (or depricating) fields for its API so what you want to scrap now may be in roadmap of new Google API releases..

How to save an image locally using Python whose URL address I already know?

Something fresh for Python 3 using Requests:

Comments in the code. Ready to use function.


import requests
from os import path

def get_image(image_url):
    """
    Get image based on url.
    :return: Image name if everything OK, False otherwise
    """
    image_name = path.split(image_url)[1]
    try:
        image = requests.get(image_url)
    except OSError:  # Little too wide, but work OK, no additional imports needed. Catch all conection problems
        return False
    if image.status_code == 200:  # we could have retrieved error page
        base_dir = path.join(path.dirname(path.realpath(__file__)), "images") # Use your own path or "" to use current working directory. Folder must exist.
        with open(path.join(base_dir, image_name), "wb") as f:
            f.write(image.content)
        return image_name

get_image("https://apod.nasddfda.gov/apod/image/2003/S106_Mishra_1947.jpg")

Java HTML Parsing

The main problem as stated by preceding coments is malformed HTML, so an html cleaner or HTML-XML converter is a must. Once you get the XML code (XHTML) there are plenty of tools to handle it. You could get it with a simple SAX handler that extracts only the data you need or any tree-based method (DOM, JDOM, etc.) that let you even modify original code.

Here is a sample code that uses HTML cleaner to get all DIVs that use a certain class and print out all Text content inside it.

import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.htmlcleaner.HtmlCleaner;
import org.htmlcleaner.TagNode;

/**
 * @author Fernando Miguélez Palomo <fernandoDOTmiguelezATgmailDOTcom>
 */
public class TestHtmlParse
{
    static final String className = "tags";
    static final String url = "http://www.stackoverflow.com";

    TagNode rootNode;

    public TestHtmlParse(URL htmlPage) throws IOException
    {
        HtmlCleaner cleaner = new HtmlCleaner();
        rootNode = cleaner.clean(htmlPage);
    }

    List getDivsByClass(String CSSClassname)
    {
        List divList = new ArrayList();

        TagNode divElements[] = rootNode.getElementsByName("div", true);
        for (int i = 0; divElements != null && i < divElements.length; i++)
        {
            String classType = divElements[i].getAttributeByName("class");
            if (classType != null && classType.equals(CSSClassname))
            {
                divList.add(divElements[i]);
            }
        }

        return divList;
    }

    public static void main(String[] args)
    {
        try
        {
            TestHtmlParse thp = new TestHtmlParse(new URL(url));

            List divs = thp.getDivsByClass(className);
            System.out.println("*** Text of DIVs with class '"+className+"' at '"+url+"' ***");
            for (Iterator iterator = divs.iterator(); iterator.hasNext();)
            {
                TagNode divElement = (TagNode) iterator.next();
                System.out.println("Text child nodes of DIV: " + divElement.getText().toString());
            }
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
}

Use getElementById on HTMLElement instead of HTMLDocument

Sub Scrape()
    Dim Browser As InternetExplorer
    Dim Document As htmlDocument
    Dim Elements As IHTMLElementCollection
    Dim Element As IHTMLElement

    Set Browser = New InternetExplorer
    Browser.Visible = True
    Browser.navigate "http://www.stackoverflow.com"

    Do While Browser.Busy And Not Browser.readyState = READYSTATE_COMPLETE
        DoEvents
    Loop

    Set Document = Browser.Document

    Set Elements = Document.getElementById("hmenus").getElementsByTagName("li")
    For Each Element In Elements
        Debug.Print Element.innerText
        'Questions
        'Tags
        'Users
        'Badges
        'Unanswered
        'Ask Question
    Next Element

    Set Document = Nothing
    Set Browser = Nothing
End Sub

Which HTML Parser is the best?

Self plug: I have just released a new Java HTML parser: jsoup. I mention it here because I think it will do what you are after.

Its party trick is a CSS selector syntax to find elements, e.g.:

String html = "<html><head><title>First parse</title></head>"
  + "<body><p>Parsed HTML into a doc.</p></body></html>";
Document doc = Jsoup.parse(html);
Elements links = doc.select("a");
Element head = doc.select("head").first();

See the Selector javadoc for more info.

This is a new project, so any ideas for improvement are very welcome!

Web-scraping JavaScript page with Python

I personally prefer using scrapy and selenium and dockerizing both in separate containers. This way you can install both with minimal hassle and crawl modern websites that almost all contain javascript in one form or another. Here's an example:

Use the scrapy startproject to create your scraper and write your spider, the skeleton can be as simple as this:

import scrapy


class MySpider(scrapy.Spider):
    name = 'my_spider'
    start_urls = ['https://somewhere.com']

    def start_requests(self):
        yield scrapy.Request(url=self.start_urls[0])


    def parse(self, response):

        # do stuff with results, scrape items etc.
        # now were just checking everything worked

        print(response.body)

The real magic happens in the middlewares.py. Overwrite two methods in the downloader middleware, __init__ and process_request, in the following way:

# import some additional modules that we need
import os
from copy import deepcopy
from time import sleep

from scrapy import signals
from scrapy.http import HtmlResponse
from selenium import webdriver

class SampleProjectDownloaderMiddleware(object):

def __init__(self):
    SELENIUM_LOCATION = os.environ.get('SELENIUM_LOCATION', 'NOT_HERE')
    SELENIUM_URL = f'http://{SELENIUM_LOCATION}:4444/wd/hub'
    chrome_options = webdriver.ChromeOptions()

    # chrome_options.add_experimental_option("mobileEmulation", mobile_emulation)
    self.driver = webdriver.Remote(command_executor=SELENIUM_URL,
                                   desired_capabilities=chrome_options.to_capabilities())


def process_request(self, request, spider):

    self.driver.get(request.url)

    # sleep a bit so the page has time to load
    # or monitor items on page to continue as soon as page ready
    sleep(4)

    # if you need to manipulate the page content like clicking and scrolling, you do it here
    # self.driver.find_element_by_css_selector('.my-class').click()

    # you only need the now properly and completely rendered html from your page to get results
    body = deepcopy(self.driver.page_source)

    # copy the current url in case of redirects
    url = deepcopy(self.driver.current_url)

    return HtmlResponse(url, body=body, encoding='utf-8', request=request)

Dont forget to enable this middlware by uncommenting the next lines in the settings.py file:

DOWNLOADER_MIDDLEWARES = {
'sample_project.middlewares.SampleProjectDownloaderMiddleware': 543,}

Next for dockerization. Create your Dockerfile from a lightweight image (I'm using python Alpine here), copy your project directory to it, install requirements:

# Use an official Python runtime as a parent image
FROM python:3.6-alpine

# install some packages necessary to scrapy and then curl because it's  handy for debugging
RUN apk --update add linux-headers libffi-dev openssl-dev build-base libxslt-dev libxml2-dev curl python-dev

WORKDIR /my_scraper

ADD requirements.txt /my_scraper/

RUN pip install -r requirements.txt

ADD . /scrapers

And finally bring it all together in docker-compose.yaml:

version: '2'
services:
  selenium:
    image: selenium/standalone-chrome
    ports:
      - "4444:4444"
    shm_size: 1G

  my_scraper:
    build: .
    depends_on:
      - "selenium"
    environment:
      - SELENIUM_LOCATION=samplecrawler_selenium_1
    volumes:
      - .:/my_scraper
    # use this command to keep the container running
    command: tail -f /dev/null

Run docker-compose up -d. If you're doing this the first time it will take a while for it to fetch the latest selenium/standalone-chrome and the build your scraper image as well.

Once it's done, you can check that your containers are running with docker ps and also check that the name of the selenium container matches that of the environment variable that we passed to our scraper container (here, it was SELENIUM_LOCATION=samplecrawler_selenium_1).

Enter your scraper container with docker exec -ti YOUR_CONTAINER_NAME sh , the command for me was docker exec -ti samplecrawler_my_scraper_1 sh, cd into the right directory and run your scraper with scrapy crawl my_spider.

The entire thing is on my github page and you can get it from here

Web scraping with Java

For tasks of this type I usually use Crawller4j + Jsoup.

With crawler4j I download the pages from a domain, you can specify which ULR with a regular expression.

With jsoup, I "parsed" the html data you have searched for and downloaded with crawler4j.

Normally you can also download data with jsoup, but Crawler4J makes it easier to find links. Another advantage of using crawler4j is that it is multithreaded and you can configure the number of concurrent threads

https://github.com/yasserg/crawler4j/wiki

What's the best way of scraping data from a website?

You will definitely want to start with a good web scraping framework. Later on you may decide that they are too limiting and you can put together your own stack of libraries but without a lot of scraping experience your design will be much worse than pjscrape or scrapy.

Note: I use the terms crawling and scraping basically interchangeable here. This is a copy of my answer to your Quora question, it's pretty long.

Tools

Get very familiar with either Firebug or Chrome dev tools depending on your preferred browser. This will be absolutely necessary as you browse the site you are pulling data from and map out which urls contain the data you are looking for and what data formats make up the responses.

You will need a good working knowledge of HTTP as well as HTML and will probably want to find a decent piece of man in the middle proxy software. You will need to be able to inspect HTTP requests and responses and understand how the cookies and session information and query parameters are being passed around. Fiddler (http://www.telerik.com/fiddler) and Charles Proxy (http://www.charlesproxy.com/) are popular tools. I use mitmproxy (http://mitmproxy.org/) a lot as I'm more of a keyboard guy than a mouse guy.

Some kind of console/shell/REPL type environment where you can try out various pieces of code with instant feedback will be invaluable. Reverse engineering tasks like this are a lot of trial and error so you will want a workflow that makes this easy.

Language

PHP is basically out, it's not well suited for this task and the library/framework support is poor in this area. Python (Scrapy is a great starting point) and Clojure/Clojurescript (incredibly powerful and productive but a big learning curve) are great languages for this problem. Since you would rather not learn a new language and you already know Javascript I would definitely suggest sticking with JS. I have not used pjscrape but it looks quite good from a quick read of their docs. It's well suited and implements an excellent solution to the problem I describe below.

A note on Regular expressions: DO NOT USE REGULAR EXPRESSIONS TO PARSE HTML. A lot of beginners do this because they are already familiar with regexes. It's a huge mistake, use xpath or css selectors to navigate html and only use regular expressions to extract data from actual text inside an html node. This might already be obvious to you, it becomes obvious quickly if you try it but a lot of people waste a lot of time going down this road for some reason. Don't be scared of xpath or css selectors, they are WAY easier to learn than regexes and they were designed to solve this exact problem.

Javascript-heavy sites

In the old days you just had to make an http request and parse the HTML reponse. Now you will almost certainly have to deal with sites that are a mix of standard HTML HTTP request/responses and asynchronous HTTP calls made by the javascript portion of the target site. This is where your proxy software and the network tab of firebug/devtools comes in very handy. The responses to these might be html or they might be json, in rare cases they will be xml or something else.

There are two approaches to this problem:

The low level approach:

You can figure out what ajax urls the site javascript is calling and what those responses look like and make those same requests yourself. So you might pull the html from http://example.com/foobar and extract one piece of data and then have to pull the json response from http://example.com/api/baz?foo=b... to get the other piece of data. You'll need to be aware of passing the correct cookies or session parameters. It's very rare, but occasionally some required parameters for an ajax call will be the result of some crazy calculation done in the site's javascript, reverse engineering this can be annoying.

The embedded browser approach:

Why do you need to work out what data is in html and what data comes in from an ajax call? Managing all that session and cookie data? You don't have to when you browse a site, the browser and the site javascript do that. That's the whole point.

If you just load the page into a headless browser engine like phantomjs it will load the page, run the javascript and tell you when all the ajax calls have completed. You can inject your own javascript if necessary to trigger the appropriate clicks or whatever is necessary to trigger the site javascript to load the appropriate data.

You now have two options, get it to spit out the finished html and parse it or inject some javascript into the page that does your parsing and data formatting and spits the data out (probably in json format). You can freely mix these two options as well.

Which approach is best?

That depends, you will need to be familiar and comfortable with the low level approach for sure. The embedded browser approach works for anything, it will be much easier to implement and will make some of the trickiest problems in scraping disappear. It's also quite a complex piece of machinery that you will need to understand. It's not just HTTP requests and responses, it's requests, embedded browser rendering, site javascript, injected javascript, your own code and 2-way interaction with the embedded browser process.

The embedded browser is also much slower at scale because of the rendering overhead but that will almost certainly not matter unless you are scraping a lot of different domains. Your need to rate limit your requests will make the rendering time completely negligible in the case of a single domain.

Rate Limiting/Bot behaviour

You need to be very aware of this. You need to make requests to your target domains at a reasonable rate. You need to write a well behaved bot when crawling websites, and that means respecting robots.txt and not hammering the server with requests. Mistakes or negligence here is very unethical since this can be considered a denial of service attack. The acceptable rate varies depending on who you ask, 1req/s is the max that the Google crawler runs at but you are not Google and you probably aren't as welcome as Google. Keep it as slow as reasonable. I would suggest 2-5 seconds between each page request.

Identify your requests with a user agent string that identifies your bot and have a webpage for your bot explaining it's purpose. This url goes in the agent string.

You will be easy to block if the site wants to block you. A smart engineer on their end can easily identify bots and a few minutes of work on their end can cause weeks of work changing your scraping code on your end or just make it impossible. If the relationship is antagonistic then a smart engineer at the target site can completely stymie a genius engineer writing a crawler. Scraping code is inherently fragile and this is easily exploited. Something that would provoke this response is almost certainly unethical anyway, so write a well behaved bot and don't worry about this.

Testing

Not a unit/integration test person? Too bad. You will now have to become one. Sites change frequently and you will be changing your code frequently. This is a large part of the challenge.

There are a lot of moving parts involved in scraping a modern website, good test practices will help a lot. Many of the bugs you will encounter while writing this type of code will be the type that just return corrupted data silently. Without good tests to check for regressions you will find out that you've been saving useless corrupted data to your database for a while without noticing. This project will make you very familiar with data validation (find some good libraries to use) and testing. There are not many other problems that combine requiring comprehensive tests and being very difficult to test.

The second part of your tests involve caching and change detection. While writing your code you don't want to be hammering the server for the same page over and over again for no reason. While running your unit tests you want to know if your tests are failing because you broke your code or because the website has been redesigned. Run your unit tests against a cached copy of the urls involved. A caching proxy is very useful here but tricky to configure and use properly.

You also do want to know if the site has changed. If they redesigned the site and your crawler is broken your unit tests will still pass because they are running against a cached copy! You will need either another, smaller set of integration tests that are run infrequently against the live site or good logging and error detection in your crawling code that logs the exact issues, alerts you to the problem and stops crawling. Now you can update your cache, run your unit tests and see what you need to change.

Legal Issues

The law here can be slightly dangerous if you do stupid things. If the law gets involved you are dealing with people who regularly refer to wget and curl as "hacking tools". You don't want this.

The ethical reality of the situation is that there is no difference between using browser software to request a url and look at some data and using your own software to request a url and look at some data. Google is the largest scraping company in the world and they are loved for it. Identifying your bots name in the user agent and being open about the goals and intentions of your web crawler will help here as the law understands what Google is. If you are doing anything shady, like creating fake user accounts or accessing areas of the site that you shouldn't (either "blocked" by robots.txt or because of some kind of authorization exploit) then be aware that you are doing something unethical and the law's ignorance of technology will be extraordinarily dangerous here. It's a ridiculous situation but it's a real one.

It's literally possible to try and build a new search engine on the up and up as an upstanding citizen, make a mistake or have a bug in your software and be seen as a hacker. Not something you want considering the current political reality.

Who am I to write this giant wall of text anyway?

I've written a lot of web crawling related code in my life. I've been doing web related software development for more than a decade as a consultant, employee and startup founder. The early days were writing perl crawlers/scrapers and php websites. When we were embedding hidden iframes loading csv data into webpages to do ajax before Jesse James Garrett named it ajax, before XMLHTTPRequest was an idea. Before jQuery, before json. I'm in my mid-30's, that's apparently considered ancient for this business.

I've written large scale crawling/scraping systems twice, once for a large team at a media company (in Perl) and recently for a small team as the CTO of a search engine startup (in Python/Javascript). I currently work as a consultant, mostly coding in Clojure/Clojurescript (a wonderful expert language in general and has libraries that make crawler/scraper problems a delight)

I've written successful anti-crawling software systems as well. It's remarkably easy to write nigh-unscrapable sites if you want to or to identify and sabotage bots you don't like.

I like writing crawlers, scrapers and parsers more than any other type of software. It's challenging, fun and can be used to create amazing things.

How to print an exception in Python 3?

I'm guessing that you need to assign the Exception to a variable. As shown in the Python 3 tutorial:

def fails():
    x = 1 / 0

try:
    fails()
except Exception as ex:
    print(ex)

To give a brief explanation, as is a pseudo-assignment keyword used in certain compound statements to assign or alias the preceding statement to a variable.

In this case, as assigns the caught exception to a variable allowing for information about the exception to stored and used later, instead of needing to be dealt with immediately. (This is discussed in detail in the Python 3 Language Reference: The try Statement.)


The other compound statement using as is the with statement:

@contextmanager
def opening(filename):
    f = open(filename)
    try:
        yield f
    finally:
        f.close()

with opening(filename) as f:
    # ...read data from f...

Here, with statements are used to wrap the execution of a block with methods defined by context managers. This functions like an extended try...except...finally statement in a neat generator package, and the as statement assigns the generator-produced result from the context manager to a variable for extended use. (This is discussed in detail in the Python 3 Language Reference: The with Statement.)


Finally, as can be used when importing modules, to alias a module to a different (usually shorter) name:

import foo.bar.baz as fbb

This is discussed in detail in the Python 3 Language Reference: The import Statement.

Using BeautifulSoup to extract text without tags

I think you can get it using subc1.text.

>>> html = """
<p>
    <strong class="offender">YOB:</strong> 1987<br />
    <strong class="offender">RACE:</strong> WHITE<br />
    <strong class="offender">GENDER:</strong> FEMALE<br />
    <strong class="offender">HEIGHT:</strong> 5'05''<br />
    <strong class="offender">WEIGHT:</strong> 118<br />
    <strong class="offender">EYE COLOR:</strong> GREEN<br />
    <strong class="offender">HAIR COLOR:</strong> BROWN<br />
</p>
"""
>>> from bs4 import BeautifulSoup
>>> soup = BeautifulSoup(html)
>>> print soup.text


YOB: 1987
RACE: WHITE
GENDER: FEMALE
HEIGHT: 5'05''
WEIGHT: 118
EYE COLOR: GREEN
HAIR COLOR: BROWN

Or if you want to explore it, you can use .contents :

>>> p = soup.find('p')
>>> from pprint import pprint
>>> pprint(p.contents)
[u'\n',
 <strong class="offender">YOB:</strong>,
 u' 1987',
 <br/>,
 u'\n',
 <strong class="offender">RACE:</strong>,
 u' WHITE',
 <br/>,
 u'\n',
 <strong class="offender">GENDER:</strong>,
 u' FEMALE',
 <br/>,
 u'\n',
 <strong class="offender">HEIGHT:</strong>,
 u" 5'05''",
 <br/>,
 u'\n',
 <strong class="offender">WEIGHT:</strong>,
 u' 118',
 <br/>,
 u'\n',
 <strong class="offender">EYE COLOR:</strong>,
 u' GREEN',
 <br/>,
 u'\n',
 <strong class="offender">HAIR COLOR:</strong>,
 u' BROWN',
 <br/>,
 u'\n']

and filter out the necessary items from the list:

>>> data = dict(zip([x.text for x in p.contents[1::4]], [x.strip() for x in p.contents[2::4]]))
>>> pprint(data)
{u'EYE COLOR:': u'GREEN',
 u'GENDER:': u'FEMALE',
 u'HAIR COLOR:': u'BROWN',
 u'HEIGHT:': u"5'05''",
 u'RACE:': u'WHITE',
 u'WEIGHT:': u'118',
 u'YOB:': u'1987'}

retrieve links from web page using python and BeautifulSoup

Here's an example using @ars accepted answer and the BeautifulSoup4, requests, and wget modules to handle the downloads.

import requests
import wget
import os

from bs4 import BeautifulSoup, SoupStrainer

url = 'https://archive.ics.uci.edu/ml/machine-learning-databases/eeg-mld/eeg_full/'
file_type = '.tar.gz'

response = requests.get(url)

for link in BeautifulSoup(response.content, 'html.parser', parse_only=SoupStrainer('a')):
    if link.has_attr('href'):
        if file_type in link['href']:
            full_path = url + link['href']
            wget.download(full_path)

Scraping data from website using vba

There are several ways of doing this. This is an answer that I write hoping that all the basics of Internet Explorer automation will be found when browsing for the keywords "scraping data from website", but remember that nothing's worth as your own research (if you don't want to stick to pre-written codes that you're not able to customize).

Please note that this is one way, that I don't prefer in terms of performance (since it depends on the browser speed) but that is good to understand the rationale behind Internet automation.

1) If I need to browse the web, I need a browser! So I create an Internet Explorer browser:

Dim appIE As Object
Set appIE = CreateObject("internetexplorer.application")

2) I ask the browser to browse the target webpage. Through the use of the property ".Visible", I decide if I want to see the browser doing its job or not. When building the code is nice to have Visible = True, but when the code is working for scraping data is nice not to see it everytime so Visible = False.

With appIE
    .Navigate "http://uk.investing.com/rates-bonds/financial-futures"
    .Visible = True
End With

3) The webpage will need some time to load. So, I will wait meanwhile it's busy...

Do While appIE.Busy
    DoEvents
Loop

4) Well, now the page is loaded. Let's say that I want to scrape the change of the US30Y T-Bond: What I will do is just clicking F12 on Internet Explorer to see the webpage's code, and hence using the pointer (in red circle) I will click on the element that I want to scrape to see how can I reach my purpose.

enter image description here

5) What I should do is straight-forward. First of all, I will get by the ID property the tr element which is containing the value:

Set allRowOfData = appIE.document.getElementById("pair_8907")

Here I will get a collection of td elements (specifically, tr is a row of data, and the td are its cells. We are looking for the 8th, so I will write:

Dim myValue As String: myValue = allRowOfData.Cells(7).innerHTML

Why did I write 7 instead of 8? Because the collections of cells starts from 0, so the index of the 8th element is 7 (8-1). Shortly analysing this line of code:

  • .Cells() makes me access the td elements;
  • innerHTML is the property of the cell containing the value we look for.

Once we have our value, which is now stored into the myValue variable, we can just close the IE browser and releasing the memory by setting it to Nothing:

appIE.Quit
Set appIE = Nothing

Well, now you have your value and you can do whatever you want with it: put it into a cell (Range("A1").Value = myValue), or into a label of a form (Me.label1.Text = myValue).

I'd just like to point you out that this is not how StackOverflow works: here you post questions about specific coding problems, but you should make your own search first. The reason why I'm answering a question which is not showing too much research effort is just that I see it asked several times and, back to the time when I learned how to do this, I remember that I would have liked having some better support to get started with. So I hope that this answer, which is just a "study input" and not at all the best/most complete solution, can be a support for next user having your same problem. Because I have learned how to program thanks to this community, and I like to think that you and other beginners might use my input to discover the beautiful world of programming.

Enjoy your practice ;)

Scraping html tables into R data frames using the XML package

Another option using Xpath.

library(RCurl)
library(XML)

theurl <- "http://en.wikipedia.org/wiki/Brazil_national_football_team"
webpage <- getURL(theurl)
webpage <- readLines(tc <- textConnection(webpage)); close(tc)

pagetree <- htmlTreeParse(webpage, error=function(...){}, useInternalNodes = TRUE)

# Extract table header and contents
tablehead <- xpathSApply(pagetree, "//*/table[@class='wikitable sortable']/tr/th", xmlValue)
results <- xpathSApply(pagetree, "//*/table[@class='wikitable sortable']/tr/td", xmlValue)

# Convert character vector to dataframe
content <- as.data.frame(matrix(results, ncol = 8, byrow = TRUE))

# Clean up the results
content[,1] <- gsub(" ", "", content[,1])
tablehead <- gsub(" ", "", tablehead)
names(content) <- tablehead

Produces this result

> head(content)
   Opponent Played Won Drawn Lost Goals for Goals against % Won
1 Argentina     94  36    24   34       148           150 38.3%
2  Paraguay     72  44    17   11       160            61 61.1%
3   Uruguay     72  33    19   20       127            93 45.8%
4     Chile     64  45    12    7       147            53 70.3%
5      Peru     39  27     9    3        83            27 69.2%
6    Mexico     36  21     6    9        69            34 58.3%

Options for HTML scraping?

I've had some success with HtmlUnit, in Java. It's a simple framework for writing unit tests on web UI's, but equally useful for HTML scraping.

Powershell equivalent of bash ampersand (&) for forking/running background processes

As long as the command is an executable or a file that has an associated executable, use Start-Process (available from v2):

Start-Process -NoNewWindow ping google.com

You can also add this as a function in your profile:

function bg() {Start-Process -NoNewWindow @args}

and then the invocation becomes:

bg ping google.com

In my opinion, Start-Job is an overkill for the simple use case of running a process in the background:

  1. Start-Job does not have access to your existing scope (because it runs in a separate session). You cannot do "Start-Job {notepad $myfile}"
  2. Start-Job does not preserve the current directory (because it runs in a separate session). You cannot do "Start-Job {notepad myfile.txt}" where myfile.txt is in the current directory.
  3. The output is not displayed automatically. You need to run Receive-Job with the ID of the job as parameter.

NOTE: Regarding your initial example, "bg sleep 30" would not work because sleep is a Powershell commandlet. Start-Process only works when you actually fork a process.

Fill formula down till last row in column

It's a one liner actually. No need to use .Autofill

Range("M3:M" & LastRow).Formula = "=G3&"",""&L3"

How to make 'submit' button disabled?

This worked for me.

.ts

newForm : FormGroup;

.html

<input type="button" [disabled]="newForm.invalid" />

How to show progress bar while loading, using ajax

Here is an example that's working for me with MVC and Javascript in the Razor. The first function calls an action via ajax on my controller and passes two parameters.

        function redirectToAction(var1, var2)
        {
            try{

                var url = '../actionnameinsamecontroller/' + routeId;

                $.ajax({
                    type: "GET",
                    url: url,
                    data: { param1: var1, param2: var2 },
                    dataType: 'html',
                    success: function(){
                    },
                    error: function(xhr, ajaxOptions, thrownError){
                        alert(error);
                    }
                });

            }
            catch(err)
            {
                alert(err.message);
            }
        }

Use the ajaxStart to start your progress bar code.

           $(document).ajaxStart(function(){
            try
            {
                // showing a modal
                $("#progressDialog").modal();

                var i = 0;
                var timeout = 750;

                (function progressbar()
                {
                    i++;
                    if(i < 1000)
                    {
                        // some code to make the progress bar move in a loop with a timeout to 
                        // control the speed of the bar
                        iterateProgressBar();
                        setTimeout(progressbar, timeout);
                    }
                }
                )();
            }
            catch(err)
            {
                alert(err.message);
            }
        });

When the process completes close the progress bar

        $(document).ajaxStop(function(){
            // hide the progress bar
            $("#progressDialog").modal('hide');
        });

What's the difference between window.location and document.location in JavaScript?

Actually I notice a difference in chrome between both , For example if you want to do a navigation to a sandboxed frame from a child frame then you can do this just with document.location but not with window.location

Sort an Array by keys based on another Array?

Just use array_merge or array_replace. Array_merge works by starting with the array you give it (in the proper order) and overwriting/adding the keys with data from your actual array:

$customer['address'] = '123 fake st';
$customer['name'] = 'Tim';
$customer['dob'] = '12/08/1986';
$customer['dontSortMe'] = 'this value doesnt need to be sorted';

$properOrderedArray = array_merge(array_flip(array('name', 'dob', 'address')), $customer);
//Or:
$properOrderedArray = array_replace(array_flip(array('name', 'dob', 'address')), $customer);

//$properOrderedArray -> array('name' => 'Tim', 'address' => '123 fake st', 'dob' => '12/08/1986', 'dontSortMe' => 'this value doesnt need to be sorted')

ps - I'm answering this 'stale' question, because I think all the loops given as previous answers are overkill.

How to change the opacity (alpha, transparency) of an element in a canvas element after it has been drawn?

I think this answers the question best, it actually changes the alpha value of something that has been drawn already. Maybe this wasn't part of the api when this question was asked.

Given 2d context c.

function reduceAlpha(x, y, w, h, dA) {
    let screenData = c.getImageData(x, y, w, h);
    for(let i = 3; i < screenData.data.length; i+=4){
        screenData.data[i] -= dA; //delta-Alpha
    }
    c.putImageData(screenData, x, y );
}

How to convert an array to object in PHP?

Inspired by all these codes, i tried to create a enhanced version with support to: specific class name, avoid constructor method, 'beans' pattern and strict mode (set only existing properties):

    class Util {

static function arrayToObject($array, $class = 'stdClass', $strict = false) {
        if (!is_array($array)) {
            return $array;
        }

        //create an instance of an class without calling class's constructor
        $object = unserialize(
                sprintf(
                        'O:%d:"%s":0:{}', strlen($class), $class
                )
        );

        if (is_array($array) && count($array) > 0) {
            foreach ($array as $name => $value) {
                $name = strtolower(trim($name));
                if (!empty($name)) {

                    if(method_exists($object, 'set'.$name)){
                        $object->{'set'.$name}(Util::arrayToObject($value));
                    }else{
                        if(($strict)){

                            if(property_exists($class, $name)){

                                $object->$name = Util::arrayToObject($value); 

                            }

                        }else{
                            $object->$name = Util::arrayToObject($value); 
                        }

                    }

                }
            }
            return $object;
        } else {
            return FALSE;
        }
        }
}

How to select a node of treeview programmatically in c#?

Call the TreeView.OnAfterSelect() protected method after you programatically select the node.

JQuery html() vs. innerHTML

If you're wondering about functionality, then jQuery's .html() performs the same intended functionality as .innerHTML, but it also performs checks for cross-browser compatibility.

For this reason, you can always use jQuery's .html() instead of .innerHTML where possible.

Npm Please try using this command again as root/administrator

You should run cmd.exe as administrator.

Follow the following steps:

  • Click Start, click All Programs, and then click Accessories.
  • Right-click Command prompt, and then click Run as administrator.

How to query GROUP BY Month in a Year

I am doing like this in MSSQL

Getting Monthly Data:

 SELECT YEAR(DATE_CREATED) [Year], MONTH(DATE_CREATED) [Month], 
     DATENAME(MONTH,DATE_CREATED) [Month Name], SUM(Num_of_Pictures) [Pictures Count]
    FROM pictures_table
    GROUP BY YEAR(DATE_CREATED), MONTH(DATE_CREATED), 
     DATENAME(MONTH, DATE_CREATED)
    ORDER BY 1,2

Getting Monthly Data using PIVOT:

SELECT *
FROM (SELECT YEAR(DATE_CREATED) [Year], 
       DATENAME(MONTH, DATE_CREATED) [Month], 
       SUM(Num_of_Pictures) [Pictures Count]
      FROM pictures_table
      GROUP BY YEAR(DATE_CREATED), 
      DATENAME(MONTH, DATE_CREATED)) AS MontlySalesData
PIVOT( SUM([Pictures Count])   
    FOR Month IN ([January],[February],[March],[April],[May],
    [June],[July],[August],[September],[October],[November],
    [December])) AS MNamePivot

How to quit android application programmatically

Similar to @MobileMateo, but in Kotlin

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
    this.finishAffinity()
} else{
    this.finish()
    System.exit(0)
}

Converting java.util.Properties to HashMap<String,String>

You can use this:

Map<String, String> map = new HashMap<>();

props.forEach((key, value) -> map.put(key.toString(), value.toString()));

Image steganography that could survive jpeg compression

Quite a few applications seem to implement Steganography on JPEG, so it's feasible:

http://www.jjtc.com/Steganography/toolmatrix.htm

Here's an article regarding a relevant algorithm (PM1) to get you started:

http://link.springer.com/article/10.1007%2Fs00500-008-0327-7#page-1

IOException: Too many open files

As you are running on Linux I suspect you are running out of file descriptors. Check out ulimit. Here is an article that describes the problem: http://www.cyberciti.biz/faq/linux-increase-the-maximum-number-of-open-files/

Can you force Visual Studio to always run as an Administrator in Windows 8?

In Windows 8 & 10, you have to right-click devenv.exe and select "Troubleshoot compatibility".

  1. Select "Troubleshoot program"
  2. Check "The program requires additional permissions"
  3. Click "Next"
  4. Click "Test the program..."
  5. Wait for the program to launch
  6. Click "Next"
  7. Select "Yes, save these settings for this program"
  8. Click "Close"

If, when you open Visual Studio it asks to save changes to devenv.sln, see this answer to disable it:

Disable Visual Studio devenv solution save dialog


If you change your mind and wish to undo the "Run As Administrator" Compatibility setting, see the answer here: How to Fix Unrecognized Guid format in Visual Studio 2015

How to deny access to a file in .htaccess

I don't believe the currently accepted answer is correct. For example, I have the following .htaccess file in the root of a virtual server (apache 2.4):

<Files "reminder.php">
require all denied
require host localhost
require ip 127.0.0.1
require ip xxx.yyy.zzz.aaa
</Files>

This prevents external access to reminder.php which is in a subdirectory. I have a similar .htaccess file on my Apache 2.2 server with the same effect:

<Files "reminder.php">
        Order Deny,Allow
        Deny from all
        Allow from localhost
        Allow from 127.0.0.1
     Allow from xxx.yyy.zzz.aaa
</Files>

I don't know for sure but I suspect it's the attempt to define the subdirectory specifically in the .htaccess file, viz <Files ./inscription/log.txt> which is causing it to fail. It would be simpler to put the .htaccess file in the same directory as log.txt i.e. in the inscription directory and it will work there.

Cannot deserialize the JSON array (e.g. [1,2,3]) into type ' ' because type requires JSON object (e.g. {"name":"value"}) to deserialize correctly

Can't add a comment to the solution but that didn't work for me. The solution that worked for me was to use:

var des = (MyClass)Newtonsoft.Json.JsonConvert.DeserializeObject(response, typeof(MyClass)); 
return des.data.Count.ToString();

Deserializing JSON array into strongly typed .NET object

Can I read the hash portion of the URL on my server-side application (PHP, Ruby, Python, etc.)?

We can do it with another approach too, Like first of all get the hash value from js and call the ajax using that parameter and can do whatever we want

"CASE" statement within "WHERE" clause in SQL Server 2008

This works

declare @v int=A
select * from Table_Name where XYZ=202 
and 
dbkey=(case @v  when A then 'Some Value 1'
else 'Some Value 2'
end)

Obtaining ExitCode using Start-Process and WaitForExit instead of -Wait

Here's a variation on this theme. I want to uninstall Cisco Amp, wait, and get the exit code. But the uninstall program starts a second program called "un_a" and exits. With this code, I can wait for un_a to finish and get the exit code of it, which is 3010 for "needs reboot". This is actually inside a .bat file.

If you've ever wanted to uninstall folding@home, it works in a similar way.

rem uninstall cisco amp, probably needs a reboot after

rem runs Un_A.exe and exits

rem start /wait isn't useful
"c:\program files\Cisco\AMP\6.2.19\uninstall.exe" /S

powershell while (! ($proc = get-process Un_A -ea 0)) { sleep 1 }; $handle = $proc.handle; 'waiting'; wait-process Un_A; exit $proc.exitcode

Static methods - How to call a method from another method?

If these don't depend on the class or instance, then just make them a function.

As this would seem like the obvious solution. Unless of course you think it's going to need to be overwritten, subclassed, etc. If so, then the previous answers are the best bet. Fingers crossed I won't get marked down for merely offering an alternative solution that may or may not fit someone’s needs ;).

As the correct answer will depend on the use case of the code in question ;)

Installing Python packages from local file system folder to virtualenv with pip

From the installing-packages page you can simply run:

pip install /srv/pkg/mypackage

where /srv/pkg/mypackage is the directory, containing setup.py.


Additionally1, you can install it from the archive file:

pip install ./mypackage-1.0.4.tar.gz

1 Although noted in the question, due to its popularity, it is also included.

How to work with string fields in a C struct?

While Richard's is what you want if you do want to go with a typedef, I'd suggest that it's probably not a particularly good idea in this instance, as you lose sight of it being a pointer, while not gaining anything.

If you were treating it a a counted string, or something with additional functionality, that might be different, but I'd really recommend that in this instance, you just get familiar with the 'standard' C string implementation being a 'char *'...

How to fix the "java.security.cert.CertificateException: No subject alternative names present" error?

To import the cert:

  1. Extract the cert from the server, e.g. openssl s_client -showcerts -connect AAA.BBB.CCC.DDD:9443 > certs.txt This will extract certs in PEM format.
  2. Convert the cert into DER format as this is what keytool expects, e.g. openssl x509 -in certs.txt -out certs.der -outform DER
  3. Now you want to import this cert into the system default 'cacert' file. Locate the system default 'cacerts' file for your Java installation. Take a look at How to obtain the location of cacerts of the default java installation?
  4. Import the certs into that cacerts file: sudo keytool -importcert -file certs.der -keystore <path-to-cacerts> Default cacerts password is 'changeit'.

If the cert is issued for an FQDN and you're trying to connect by IP address in your Java code, then this should probably be fixed in your code rather than messing with certificate itself. Change your code to connect by FQDN. If FQDN is not resolvable on your dev machine, simply add it to your hosts file, or configure your machine with DNS server that can resolve this FQDN.

How to post an array of complex objects with JSON, jQuery to ASP.NET MVC Controller?

In .NET4.5, MVC 5 no need for widgets.

Javascript:

object in JS: enter image description here

mechanism that does post.

    $('.button-green-large').click(function() {
        $.ajax({
            url: 'Quote',
            type: "POST",
            dataType: "json",
            data: JSON.stringify(document.selectedProduct),
            contentType: 'application/json; charset=utf-8',
        });
    });

C#

Objects:

public class WillsQuoteViewModel
{
    public string Product { get; set; }

    public List<ClaimedFee> ClaimedFees { get; set; }
}

public partial class ClaimedFee //Generated by EF6
{
    public long Id { get; set; }
    public long JourneyId { get; set; }
    public string Title { get; set; }
    public decimal Net { get; set; }
    public decimal Vat { get; set; }
    public string Type { get; set; }

    public virtual Journey Journey { get; set; }
}

Controller:

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Quote(WillsQuoteViewModel data)
{
....
}

Object received:

enter image description here

Hope this saves you some time.

How to programmatically set drawableLeft on Android button?

Try this:

((Button)btn).getCompoundDrawables()[0].setAlpha(btn.isEnabled() ? 255 : 100);

Cannot execute RUN mkdir in a Dockerfile

The problem is that /var/www doesn't exist either, and mkdir isn't recursive by default -- it expects the immediate parent directory to exist.

Use:

mkdir -p /var/www/app

...or install a package that creates a /var/www prior to reaching this point in your Dockerfile.

How to embed fonts in CSS?

I used Ataturk's font like this. I didn't use "TTF" version. I translated orginal font version ("otf" version) to "eot" and "woof" version. Then It works in local but not working when I uploaded the files to server. So I added "TTF" version too like this. Now, It's working on Chrome and Firefox but Internet Explorer still defence. When you installed on your computer "Ataturk" font, then working IE too. But I wanted to use this font without installing.

@font-face {
    font-family: 'Ataturk';
    font-style: normal;
    font-weight: normal;
    src: url('font/ataturk.eot');
    src: local('Ataturk Regular'), url('font/ataturk.ttf') format('truetype'), 
    url('font/ataturk.woff') format('woff');
}

You can see it on my website here: http://www.canotur.com

get the value of "onclick" with jQuery?

i have never done this, but it would be done like this:

var script = $('#google').attr("onclick")

How to Use slideDown (or show) function on a table row?

Here's a plug-in that I wrote up for this, it takes a little from Fletch's implementation, but mine is used solely to slide a row up or down (no inserting rows).

(function($) {
var sR = {
    defaults: {
        slideSpeed: 400,
        easing: false,
        callback: false     
    },
    thisCallArgs: {
        slideSpeed: 400,
        easing: false,
        callback: false
    },
    methods: {
        up: function (arg1,arg2,arg3) {
            if(typeof arg1 == 'object') {
                for(p in arg1) {
                    sR.thisCallArgs.eval(p) = arg1[p];
                }
            }else if(typeof arg1 != 'undefined' && (typeof arg1 == 'number' || arg1 == 'slow' || arg1 == 'fast')) {
                sR.thisCallArgs.slideSpeed = arg1;
            }else{
                sR.thisCallArgs.slideSpeed = sR.defaults.slideSpeed;
            }

            if(typeof arg2 == 'string'){
                sR.thisCallArgs.easing = arg2;
            }else if(typeof arg2 == 'function'){
                sR.thisCallArgs.callback = arg2;
            }else if(typeof arg2 == 'undefined') {
                sR.thisCallArgs.easing = sR.defaults.easing;    
            }
            if(typeof arg3 == 'function') {
                sR.thisCallArgs.callback = arg3;
            }else if(typeof arg3 == 'undefined' && typeof arg2 != 'function'){
                sR.thisCallArgs.callback = sR.defaults.callback;    
            }
            var $cells = $(this).find('td');
            $cells.wrapInner('<div class="slideRowUp" />');
            var currentPadding = $cells.css('padding');
            $cellContentWrappers = $(this).find('.slideRowUp');
            $cellContentWrappers.slideUp(sR.thisCallArgs.slideSpeed,sR.thisCallArgs.easing).parent().animate({
                                                                                                                paddingTop: '0px',
                                                                                                                paddingBottom: '0px'},{
                                                                                                                complete: function () {
                                                                                                                    $(this).children('.slideRowUp').replaceWith($(this).children('.slideRowUp').contents());
                                                                                                                    $(this).parent().css({'display':'none'});
                                                                                                                    $(this).css({'padding': currentPadding});
                                                                                                                }});
            var wait = setInterval(function () {
                if($cellContentWrappers.is(':animated') === false) {
                    clearInterval(wait);
                    if(typeof sR.thisCallArgs.callback == 'function') {
                        sR.thisCallArgs.callback.call(this);
                    }
                }
            }, 100);                                                                                                    
            return $(this);
        },
        down: function (arg1,arg2,arg3) {
            if(typeof arg1 == 'object') {
                for(p in arg1) {
                    sR.thisCallArgs.eval(p) = arg1[p];
                }
            }else if(typeof arg1 != 'undefined' && (typeof arg1 == 'number' || arg1 == 'slow' || arg1 == 'fast')) {
                sR.thisCallArgs.slideSpeed = arg1;
            }else{
                sR.thisCallArgs.slideSpeed = sR.defaults.slideSpeed;
            }

            if(typeof arg2 == 'string'){
                sR.thisCallArgs.easing = arg2;
            }else if(typeof arg2 == 'function'){
                sR.thisCallArgs.callback = arg2;
            }else if(typeof arg2 == 'undefined') {
                sR.thisCallArgs.easing = sR.defaults.easing;    
            }
            if(typeof arg3 == 'function') {
                sR.thisCallArgs.callback = arg3;
            }else if(typeof arg3 == 'undefined' && typeof arg2 != 'function'){
                sR.thisCallArgs.callback = sR.defaults.callback;    
            }
            var $cells = $(this).find('td');
            $cells.wrapInner('<div class="slideRowDown" style="display:none;" />');
            $cellContentWrappers = $cells.find('.slideRowDown');
            $(this).show();
            $cellContentWrappers.slideDown(sR.thisCallArgs.slideSpeed, sR.thisCallArgs.easing, function() { $(this).replaceWith( $(this).contents()); });

            var wait = setInterval(function () {
                if($cellContentWrappers.is(':animated') === false) {
                    clearInterval(wait);
                    if(typeof sR.thisCallArgs.callback == 'function') {
                        sR.thisCallArgs.callback.call(this);
                    }
                }
            }, 100);
            return $(this);
        }
    }
};

$.fn.slideRow = function(method,arg1,arg2,arg3) {
    if(typeof method != 'undefined') {
        if(sR.methods[method]) {
            return sR.methods[method].apply(this, Array.prototype.slice.call(arguments,1));
        }
    }
};
})(jQuery);

Basic Usage:

$('#row_id').slideRow('down');
$('#row_id').slideRow('up');

Pass slide options as individual arguments:

$('#row_id').slideRow('down', 500); //slide speed
$('#row_id').slideRow('down', 500, function() { alert('Row available'); }); // slide speed and callback function
$('#row_id').slideRow('down', 500, 'linear', function() { alert('Row available'); }); slide speed, easing option and callback function
$('#row_id').slideRow('down', {slideSpeed: 500, easing: 'linear', callback: function() { alert('Row available');} }); //options passed as object

Basically, for the slide down animation, the plug-in wraps the contents of the cells in DIVs, animates those, then removes them, and vice versa for the slide up (with some extra steps to get rid of the cell padding). It also returns the object you called it on, so you can chain methods like so:

$('#row_id').slideRow('down').css({'font-color':'#F00'}); //make the text in the row red

Hope this helps someone.

Get folder name of the file in Python

You are looking to use dirname. If you only want that one directory, you can use os.path.basename,

When put all together it looks like this:

os.path.basename(os.path.dirname('dir/sub_dir/other_sub_dir/file_name.txt'))

That should get you "other_sub_dir"

The following is not the ideal approach, but I originally proposed,using os.path.split, and simply get the last item. which would look like this:

os.path.split(os.path.dirname('dir/sub_dir/other_sub_dir/file_name.txt'))[-1]

Metadata file '.dll' could not be found

In my case, I have my installed directory in mistaken ways.

If your solution path is something like "My Project%2c Very Popular%2c Unit Testing%2c Software and Hardware.zip", it cannot resolve the metadata file, perhaps we should prevent some invalid words like %2c.

Renaming the path into normal name resolved my issue.

Setting new value for an attribute using jQuery

Works fine for me

See example here. http://jsfiddle.net/blowsie/c6VAy/

Make sure your jquery is inside $(document).ready function or similar.

Also you can improve your code by using jquery data

$('#amount').data('min','1000');

<div id="amount" data-min=""></div>

Update,

A working example of your full code (pretty much) here. http://jsfiddle.net/blowsie/c6VAy/3/

How to retrieve current workspace using Jenkins Pipeline Groovy script?

This is where you can find the answer in the job-dsl-plugin code.

Basically you can do something like this:

readFileFromWorkspace('src/main/groovy/com/groovy/jenkins/scripts/enable_safehtml.groovy')

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

For my example :first 'MainActivity' implements 'View.OnClickListener' than start the code ....

@Override

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    init();}


public void init(){

    foryou = (Button) this.findViewById(R.id.btn_foryou);
    following = (Button) findViewById(R.id.btn_following);
    popular = (Button) findViewById(R.id.btn_popular);
    watching = (Button) findViewById(R.id.btn_continuewatching);
    mProgress = (ProgressBar) findViewById(R.id.pb);

    foryou.setOnClickListener(this);
    following.setOnClickListener(this);
    popular.setOnClickListener(this);
    watching.setOnClickListener(this);
    mProgress.setOnClickListener(this);
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.btn_foryou:
            foryou.setPaintFlags(foryou.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);

            break;
        case R.id.btn_following:
            following.setPaintFlags(following.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);

            break;
        case R.id.btn_popular:
            popular.setPaintFlags(popular.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);

            break;
        case R.id.btn_continuewatching:
            watching.setPaintFlags(watching.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);

            break;
        case R.id.btn_5:
            // foryou.setPaintFlags(foryou.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);

            break;
        default:
            foryou.setPaintFlags(foryou.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);

    }
}

'POCO' definition

"Plain Old C# Object"

Just a normal class, no attributes describing infrastructure concerns or other responsibilities that your domain objects shouldn't have.

EDIT - as other answers have stated, it is technically "Plain Old CLR Object" but I, like David Arno comments, prefer "Plain Old Class Object" to avoid ties to specific languages or technologies.

TO CLARIFY: In other words, they don’t derive from some special base class, nor do they return any special types for their properties.

See below for an example of each.

Example of a POCO:

public class Person
{
    public string Name { get; set; }

    public int Age { get; set; }
}

Example of something that isn’t a POCO:

public class PersonComponent : System.ComponentModel.Component
{
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
    public string Name { get; set; }

    public int Age { get; set; }
}

The example above both inherits from a special class to give it additional behavior as well as uses a custom attribute to change behavior… the same properties exist on both classes, but one is not just a plain old object anymore.

C++, copy set to vector

You need to use a back_inserter:

std::copy(input.begin(), input.end(), std::back_inserter(output));

std::copy doesn't add elements to the container into which you are inserting: it can't; it only has an iterator into the container. Because of this, if you pass an output iterator directly to std::copy, you must make sure it points to a range that is at least large enough to hold the input range.

std::back_inserter creates an output iterator that calls push_back on a container for each element, so each element is inserted into the container. Alternatively, you could have created a sufficient number of elements in the std::vector to hold the range being copied:

std::vector<double> output(input.size());
std::copy(input.begin(), input.end(), output.begin());

Or, you could use the std::vector range constructor:

std::vector<double> output(input.begin(), input.end()); 

java.lang.RuntimeException: Unable to start activity ComponentInfo

It was my own stupidity:

java.text.DateFormat dateFormat = android.text.format.DateFormat.getDateFormat(getApplicationContext());

Putting this inside onCreate() method fixed my problem.

Switch statement fallthrough in C#?

You can 'goto case label' http://www.blackwasp.co.uk/CSharpGoto.aspx

The goto statement is a simple command that unconditionally transfers the control of the program to another statement. The command is often criticised with some developers advocating its removal from all high-level programming languages because it can lead to spaghetti code. This occurs when there are so many goto statements or similar jump statements that the code becomes difficult to read and maintain. However, there are programmers who point out that the goto statement, when used carefully, provides an elegant solution to some problems...

Can constructors be async?

if you make constructor asynchronous, after creating an object, you may fall into problems like null values instead of instance objects. For instance;

MyClass instance = new MyClass();
instance.Foo(); // null exception here

That's why they don't allow this i guess.

How can I check if a date is the same day as datetime.today()?

You can set the hours, minutes, seconds and microseconds to whatever you like

datetime.datetime.today().replace(hour=0, minute=0, second=0, microsecond=0)

but trutheality's answer is probably best when they are all to be zero and you can just compare the .date()s of the times

Maybe it is faster though if you have to compare hundreds of datetimes because you only need to do the replace() once vs hundreds of calls to date()

How to initialize private static members in C++?

You can also include the assignment in the header file if you use header guards. I have used this technique for a C++ library I have created. Another way to achieve the same result is to use static methods. For example...

class Foo
   {
   public:
     int GetMyStatic() const
     {
       return *MyStatic();
     }

   private:
     static int* MyStatic()
     {
       static int mStatic = 0;
       return &mStatic;
     }
   }

The above code has the "bonus" of not requiring a CPP/source file. Again, a method I use for my C++ libraries.

Convert ASCII TO UTF-8 Encoding

If you know for sure that your current encoding is pure ASCII, then you don't have to do anything because ASCII is already a valid UTF-8.

But if you still want to convert, just to be sure that its UTF-8, then you can use iconv

$string = iconv('ASCII', 'UTF-8//IGNORE', $string);

The IGNORE will discard any invalid characters just in case some were not valid ASCII.

Enabling/installing GD extension? --without-gd

For php7.1 do:

sudo apt-get install php7.1-gd

and restart webserver. For apache do

sudo service apache2 restart

How to make html <select> element look like "disabled", but pass values?

<select id="test" name="sel">
  <option disabled>1</option>
  <option disabled>2</option>
</select>   

or you can use jQuery

$("#test option:not(:selected)").prop("disabled", true);

Is there an opposite of include? for Ruby Arrays?

if @players.exclude?(p.name)
    ...
end

ActiveSupport adds the exclude? method to Array, Hash, and String. This is not pure Ruby, but is used by a LOT of rubyists.

Source: Active Support Core Extensions (Rails Guides)

CSS height 100% percent not working

I believe you need to make sure that all the container div tags above the 100% height div also has 100% height set on them including the body tag and html.

Playing .mp3 and .wav in Java?

you can play .wav only with java API:

import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;

code:

AudioInputStream audioIn = AudioSystem.getAudioInputStream(MyClazz.class.getResource("music.wav"));
Clip clip = AudioSystem.getClip();
clip.open(audioIn);
clip.start();

And play .mp3 with jLayer

What's faster, SELECT DISTINCT or GROUP BY in MySQL?

If you have an index on profession, these two are synonyms.

If you don't, then use DISTINCT.

GROUP BY in MySQL sorts results. You can even do:

SELECT u.profession FROM users u GROUP BY u.profession DESC

and get your professions sorted in DESC order.

DISTINCT creates a temporary table and uses it for storing duplicates. GROUP BY does the same, but sortes the distinct results afterwards.

So

SELECT DISTINCT u.profession FROM users u

is faster, if you don't have an index on profession.

Could not load file or assembly 'log4net, Version=1.2.10.0, Culture=neutral, PublicKeyToken=692fbea5521e1304'

If you are building a windows app try to build as x64 instead of Any CPU. It should work fine.

Count the frequency that a value occurs in a dataframe column

You can also do this with pandas by broadcasting your columns as categories first, e.g. dtype="category" e.g.

cats = ['client', 'hotel', 'currency', 'ota', 'user_country']

df[cats] = df[cats].astype('category')

and then calling describe:

df[cats].describe()

This will give you a nice table of value counts and a bit more :):

    client  hotel   currency    ota user_country
count   852845  852845  852845  852845  852845
unique  2554    17477   132 14  219
top 2198    13202   USD Hades   US
freq    102562  8847    516500  242734  340992

Send POST request with JSON data using Volley

final String URL = "/volley/resource/12";
// Post params to be sent to the server
HashMap<String, String> params = new HashMap<String, String>();
params.put("token", "AbCdEfGh123456");

JsonObjectRequest req = new JsonObjectRequest(URL, new JSONObject(params),
       new Response.Listener<JSONObject>() {
           @Override
           public void onResponse(JSONObject response) {
               try {
                   VolleyLog.v("Response:%n %s", response.toString(4));
               } catch (JSONException e) {
                   e.printStackTrace();
               }
           }
       }, new Response.ErrorListener() {
           @Override
           public void onErrorResponse(VolleyError error) {
               VolleyLog.e("Error: ", error.getMessage());
           }
       });

// add the request object to the queue to be executed
ApplicationController.getInstance().addToRequestQueue(req);

refer

Javascript Regular Expression Remove Spaces

This works just as well: http://jsfiddle.net/maniator/ge59E/3/

var reg = new RegExp(" ","g"); //<< just look for a space.

How to convert a pymongo.cursor.Cursor into a dict?

Easy

import pymongo
conn = pymongo.MongoClient()
db = conn.test #test is my database
col = db.spam #Here spam is my collection
array = list(col.find())

print array

There you go

ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749)

I ran this on MacOS /Applications/Python\ 3.6/Install\ Certificates.command

How to use pip with python 3.4 on windows?

I know this is a very old topic, but in case someone needs it

there is no pip in python 3.4, so we have to use python -m ensurepip to install pip

Why would you use Expression<Func<T>> rather than Func<T>?

When you want to treat lambda expressions as expression trees and look inside them instead of executing them. For example, LINQ to SQL gets the expression and converts it to the equivalent SQL statement and submits it to server (rather than executing the lambda).

Conceptually, Expression<Func<T>> is completely different from Func<T>. Func<T> denotes a delegate which is pretty much a pointer to a method and Expression<Func<T>> denotes a tree data structure for a lambda expression. This tree structure describes what a lambda expression does rather than doing the actual thing. It basically holds data about the composition of expressions, variables, method calls, ... (for example it holds information such as this lambda is some constant + some parameter). You can use this description to convert it to an actual method (with Expression.Compile) or do other stuff (like the LINQ to SQL example) with it. The act of treating lambdas as anonymous methods and expression trees is purely a compile time thing.

Func<int> myFunc = () => 10; // similar to: int myAnonMethod() { return 10; }

will effectively compile to an IL method that gets nothing and returns 10.

Expression<Func<int>> myExpression = () => 10;

will be converted to a data structure that describes an expression that gets no parameters and returns the value 10:

Expression vs Func larger image

While they both look the same at compile time, what the compiler generates is totally different.

How to get the last element of a slice?

For just reading the last element of a slice:

sl[len(sl)-1]

For removing it:

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

See this page about slice tricks

Looping through JSON with node.js

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

Jquery .on('scroll') not firing the event while scrolling

I know that this is quite old thing, but I solved issue like that: I had parent and child element was scrollable.

   if ($('#parent > *').length == 0 ){
        var wait = setInterval(function() {
            if($('#parent > *').length != 0 ) {
                $('#parent .child').bind('scroll',function() {
                  //do staff
                });
                clearInterval(wait);
            },1000);
        }

The issue I had is that I didn't know when the child is loaded to DOM, but I kept checking for it every second.

NOTE:this is useful if it happens soon but not right after document load, otherwise it will use clients computing power for no reason.

How to define two fields "unique" as couple

There is a simple solution for you called unique_together which does exactly what you want.

For example:

class MyModel(models.Model):
  field1 = models.CharField(max_length=50)
  field2 = models.CharField(max_length=50)

  class Meta:
    unique_together = ('field1', 'field2',)

And in your case:

class Volume(models.Model):
  id = models.AutoField(primary_key=True)
  journal_id = models.ForeignKey(Journals, db_column='jid', null=True, verbose_name = "Journal")
  volume_number = models.CharField('Volume Number', max_length=100)
  comments = models.TextField('Comments', max_length=4000, blank=True)

  class Meta:
    unique_together = ('journal_id', 'volume_number',)

node.js execute system command synchronously

You can achieve this using fibers. For example, using my Common Node library, the code would look like this:

result = require('subprocess').command('node -v');

laravel Eloquent ORM delete() method

$model=User::where('id',$id)->delete();

Running Python in PowerShell?

Go to Python Website/dowloads/windows. Download Windows x86-64 embeddable zip file. 2. Open Windows Explorer

open zipped folder python-3.7.0 In the windows toolbar with the Red flair saying “Compressed Folder Tool” Press “Extract” button on the tool bar with “File” “Home “Share” “View” Select Extract all Extraction process is not covered yet Once extracted save onto SDD or fastest memory device. Not usb. HDD is fine. SDD Users/butte/ProgramFiles blah blah ooooor D:\Python Or Hook up to your cloud 3. Click your User Icon in the Windows tool bar.

Search environment variable Proceed with progressing with “Environment Variables” button press Under the “user variables” table select “New..” After the Canvas of Information Add Python in Variable Name Select the “D:\Python\python-3.7.0-embed-amd64\python.exe;” click ok Under the “System Variables” label and in the Canvas the first row has a value marked “Path” Select “Edit” when “Path” is highlighted. Select “New” Enter D:\Python\python-3.7.0-embed-amd click ok Ok Save and double check Open Power Shell python --help

python --version

Source to tutorial https://thedishbunnybitch.com/2018/08/11/installing-python-on-windows-10-for-powershell/

ThreadStart with parameters

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Threading;

namespace ConsoleApp6
{
    class Program
    {
        static void Main(string[] args)
        {

            int x = 10;
            Thread t1 =new Thread(new ParameterizedThreadStart(order1));
            t1.IsBackground = true;//i can stope 
            t1.Start(x);

            Thread t2=new Thread(order2);
            t2.Priority = ThreadPriority.Highest;
            t2.Start();

            Console.ReadKey();
        }//Main

        static void  order1(object args)
        {
            int x = (int)args;


                for (int i = 0; i < x; i++)
            {
                Console.ForegroundColor = ConsoleColor.Green;
                Console.Write(i.ToString() + " ");
            }
        }

        static void order2()
        {
            for (int i = 100; i > 0; i--)
            {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.Write(i.ToString() + " ");
            }
        }`enter code here`
    }
}

How to use ? : if statements with Razor and inline code blocks

In most cases the solution of CD.. will work perfectly fine. However I had a bit more twisted situation:

 @(String.IsNullOrEmpty(Model.MaidenName) ? "&nbsp;" : Model.MaidenName)

This would print me "&nbsp;" in my page, respectively generate the source &amp;nbsp;. Now there is a function Html.Raw("&nbsp;") which is supposed to let you write source code, except in this constellation it throws a compiler error:

Compiler Error Message: CS0173: Type of conditional expression cannot be determined because there is no implicit conversion between 'System.Web.IHtmlString' and 'string'

So I ended up writing a statement like the following, which is less nice but works even in my case:

@if (String.IsNullOrEmpty(Model.MaidenName)) { @Html.Raw("&nbsp;") } else { @Model.MaidenName } 

Note: interesting thing is, once you are inside the curly brace, you have to restart a Razor block.

header('HTTP/1.0 404 Not Found'); not doing anything

Another reason may be if you add any html tag before this redirect. Look carefully, you may left DOCTYPE or any html comment before this line.

Singleton design pattern vs Singleton beans in Spring container

There is a very fundamental difference between the two. In case of Singleton design pattern, only one instance of a class will be created per classLoader while that is not the case with Spring singleton as in the later one shared bean instance for the given id per IoC container is created.

For example, if I have a class with the name "SpringTest" and my XML file looks something like this :-

<bean id="test1" class="com.SpringTest" scope="singleton">
        --some properties here
</bean>    
<bean id="test2" class="com.SpringTest" scope="singleton">
        --some properties here   
</bean>

So now in the main class if you will check the reference of the above two it will return false as according to Spring documentation:-

When a bean is a singleton, only one shared instance of the bean will be managed, and all requests for beans with an id or ids matching that bean definition will result in that one specific bean instance being returned by the Spring container

So as in our case, the classes are the same but the id's that we have provided are different hence resulting in two different instances being created.

In what cases do I use malloc and/or new?

If you are using C++, try to use new/delete instead of malloc/calloc as they are operators. For malloc/calloc, you need to include another header. Don't mix two different languages in the same code. Their work is similar in every manner, both allocates memory dynamically from heap segment in hash table.

How can I prevent the TypeError: list indices must be integers, not tuple when copying a python list to a numpy array?

Just if someone is having this issue and hadn't done list[index, sub-index], you could be having the problem because you're missing a comma between two arrays in an array of arrays (It happened to me).

Removing spaces from a variable input using PowerShell 4.0

The Replace operator means Replace something with something else; do not be confused with removal functionality.

Also you should send the result processed by the operator to a variable or to another operator. Neither .Replace(), nor -replace modifies the original variable.

To remove all spaces, use 'Replace any space symbol with empty string'

$string = $string -replace '\s',''

To remove all spaces at the beginning and end of the line, and replace all double-and-more-spaces or tab symbols to spacebar symbol, use

$string = $string -replace '(^\s+|\s+$)','' -replace '\s+',' '

or the more native System.String method

$string = $string.Trim()

Regexp is preferred, because ' ' means only 'spacebar' symbol, and '\s' means 'spacebar, tab and other space symbols'. Note that $string.Replace() does 'Normal' replace, and $string -replace does RegEx replace, which is more heavy but more functional.

Note that RegEx have some special symbols like dot (.), braces ([]()), slashes (\), hats (^), mathematical signs (+-) or dollar signs ($) that need do be escaped. ( 'my.space.com' -replace '\.','-' => 'my-space-com'. A dollar sign with a number (ex $1) must be used on a right part with care

'2033' -replace '(\d+)',$( 'Data: $1')
Data: 2033

UPDATE: You can also use $str = $str.Trim(), along with TrimEnd() and TrimStart(). Read more at System.String MSDN page.

How to disable button in React.js

this.input is undefined until the ref callback is called. Try setting this.input to some initial value in your constructor.

From the React docs on refs, emphasis mine:

the callback will be executed immediately after the component is mounted or unmounted

Hide HTML element by id

I found that the following code, when inserted into the site's footer, worked well enough:

<script type="text/javascript">
$("#nav-ask").remove();
</script>

This may or may not require jquery. The site I'm editing has jquery, but unfortunately I'm no javascripter, so I only have a limited knowledge of what's going on here, and the requirements of this code snippet...

How to call a method in MainActivity from another class?

Simply, You can make this method static as below:

public static void startChronometer(){
    mChronometer.start();
    showElapsedTime();
} 

you can call this function in other class as below:

MainActivity.startChronometer();

Dynamically add properties to a existing object

Take a look at the Clay library:

http://clay.codeplex.com/

It provides something similar to the ExpandoObject but with a bunch of extra features. Here is blog post explaining how to use it:

http://weblogs.asp.net/bleroy/archive/2010/08/18/clay-malleable-c-dynamic-objects-part-2.aspx

(be sure to read the IPerson interface example)

Git: Recover deleted (remote) branch

If the delete is recent enough (Like an Oh-NO! moment) you should still have a message:

Deleted branch <branch name> (was abcdefghi).

you can still run:

git checkout abcdefghi

git checkout -b <some new branch name or the old one>

How to fix warning from date() in PHP"

You could also use this:

ini_alter('date.timezone','Asia/Calcutta');

You should call this before calling any date function. It accepts the key as the first parameter to alter PHP settings during runtime and the second parameter is the value.

I had done these things before I figured out this:

  1. Changed the PHP.timezone to "Asia/Calcutta" - but did not work
  2. Changed the lat and long parameters in the ini - did not work
  3. Used date_default_timezone_set("Asia/Calcutta"); - did not work
  4. Used ini_alter() - IT WORKED
  5. Commented date_default_timezone_set("Asia/Calcutta"); - IT WORKED
  6. Reverted the changes made to the PHP.ini - IT WORKED

For me the init_alter() method got it all working.

I am running Apache 2 (pre-installed), PHP 5.3 on OSX mountain lion

how to convert binary string to decimal?

I gathered all what others have suggested and created following function which has 3 arguments, the number and the base which that number has come from and the base which that number is going to be on:

changeBase(1101000, 2, 10) => 104

Run Code Snippet to try it yourself:

_x000D_
_x000D_
function changeBase(number, fromBase, toBase) {_x000D_
                        if (fromBase == 10)_x000D_
                            return (parseInt(number)).toString(toBase)_x000D_
                        else if (toBase == 10)_x000D_
                            return parseInt(number, fromBase);_x000D_
                        else{_x000D_
                            var numberInDecimal = parseInt(number, fromBase);_x000D_
                            return (parseInt(numberInDecimal)).toString(toBase);_x000D_
                    }_x000D_
}_x000D_
_x000D_
$("#btnConvert").click(function(){_x000D_
  var number = $("#txtNumber").val(),_x000D_
  fromBase = $("#txtFromBase").val(),_x000D_
  toBase = $("#txtToBase").val();_x000D_
  $("#lblResult").text(changeBase(number, fromBase, toBase));_x000D_
});
_x000D_
#lblResult{_x000D_
  padding: 20px;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<input id="txtNumber" type="text" placeholder="Number" />_x000D_
<input id="txtFromBase" type="text" placeholder="From Base" />_x000D_
<input id="txtToBase" type="text" placeholder="To Base" />_x000D_
<input id="btnConvert" type="button" value="Convert" />_x000D_
<span id="lblResult"></span>_x000D_
_x000D_
<p>Hint: <br />_x000D_
Try 110, 2, 10 and it will return 6; (110)<sub>2</sub> = 6<br />_x000D_
_x000D_
or 2d, 16, 10 => 45 meaning: (2d)<sub>16</sub> = 45<br />_x000D_
or 45, 10, 16 => 2d meaning: 45 = (2d)<sub>16</sub><br />_x000D_
or 2d, 2, 16 => 2d meaning: (101101)<sub>2</sub> = (2d)<sub>16</sub><br />_x000D_
</p>
_x000D_
_x000D_
_x000D_

FYI: If you want to pass 2d as hex number, you need to send it as a string so it goes like this: changeBase('2d', 16, 10)

How to draw a custom UIView that is just a circle - iPhone app

Here is another way by using UIBezierPath (maybe it's too late ^^) Create a circle and mask UIView with it, as follows:

UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
view.backgroundColor = [UIColor blueColor];

CAShapeLayer *shape = [CAShapeLayer layer];
UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:view.center radius:(view.bounds.size.width / 2) startAngle:0 endAngle:(2 * M_PI) clockwise:YES];
shape.path = path.CGPath;
view.layer.mask = shape;

Replacing instances of a character in a string

If you are replacing by an index value specified in variable 'n', then try the below:

def missing_char(str, n):
 str=str.replace(str[n],":")
 return str

<> And Not In VB.NET

in fact the Is is really good, since to the developpers, you may want to override the operator ==, to compare with the value. say you have a class A, operator == of A is to compare some of the field of A to the parameter. then you will be in trouble in c# to verify whether the object of A is null with following code,

    A a = new A();
...
    if (a != null)
it will totally wrong, you always need to use if((object)a != null)
but in vb.net you cannot write in this way, you always need to write
    if not a is nothing then
or
    if a isnot nothing then

which just as Christian said, vb.net does not 'expected' anything.

In java how to get substring from a string till a character c?

or you may try something like

"abc.def.ghi".substring(0,"abc.def.ghi".indexOf(c)-1);

path.join vs path.resolve with __dirname

From the doc for path.resolve:

The resulting path is normalized and trailing slashes are removed unless the path is resolved to the root directory.

But path.join keeps trailing slashes

So

__dirname = '/';
path.resolve(__dirname, 'foo/'); // '/foo'
path.join(__dirname, 'foo/'); // '/foo/'

Selenium: WebDriverException:Chrome failed to start: crashed as google-chrome is no longer running so ChromeDriver is assuming that Chrome has crashed

For RobotFramework

I solved it! using --no-sandbox

${chrome_options}=  Evaluate  sys.modules['selenium.webdriver'].ChromeOptions()  sys, selenium.webdriver
Call Method    ${chrome_options}    add_argument    test-type
Call Method    ${chrome_options}    add_argument    --disable-extensions
Call Method    ${chrome_options}    add_argument    --headless
Call Method    ${chrome_options}    add_argument    --disable-gpu
Call Method    ${chrome_options}    add_argument    --no-sandbox
Create Webdriver    Chrome    chrome_options=${chrome_options}

Instead of

Open Browser    about:blank    headlesschrome
Open Browser    about:blank    chrome

Setting an image for a UIButton in code

Swift 3 version (butt_img must be an Image Set into Assets.xcassets or Images.xcassets folder in Xcode):

btnTwo.setBackgroundImage(UIImage(named: "butt_img"), for: .normal)
btnTwo.setTitle("My title", for: .normal)

Anyway, if you want the image to be scaled to fill the button's size, you may add a UIImageView over it and assign it your image:

let img = UIImageView()
img.frame = btnTwo.frame
img.contentMode = .scaleAspectFill
img.clipsToBounds = true
img.image = UIImage(named: "butt_img")
btnTwo.addSubview(img)

What is the behavior difference between return-path, reply-to and from?

I had to add a Return-Path header in emails send by a Redmine instance. I agree with greatwolf only the sender can determine a correct (non default) Return-Path. The case is the following : E-mails are send with the default email address : [email protected] But we want that the real user initiating the action receives the bounce emails, because he will be the one knowing how to fix wrong recipients emails (and not the application adminstrators that have other cats to whip :-) ). We use this and it works perfectly well with exim on the application server and zimbra as the final company mail server.

How do you add UI inside cells in a google spreadsheet using app script?

Buttons can be added to frozen rows as images. Assigning a function within the attached script to the button makes it possible to run the function. The comment which says you can not is of course a very old comment, possibly things have changed now.

Equivalent of typedef in C#

I think there is no typedef. You could only define a specific delegate type instead of the generic one in the GenericClass, i.e.

public delegate GenericHandler EventHandler<EventData>

This would make it shorter. But what about the following suggestion:

Use Visual Studio. This way, when you typed

gcInt.MyEvent += 

it already provides the complete event handler signature from Intellisense. Press TAB and it's there. Accept the generated handler name or change it, and then press TAB again to auto-generate the handler stub.

Getting URL parameter in java and extract a specific text from that URL

I have something like this:

import org.apache.http.NameValuePair;
import org.apache.http.client.utils.URIBuilder;

private String getParamValue(String link, String paramName) throws URISyntaxException {
        List<NameValuePair> queryParams = new URIBuilder(link).getQueryParams();
        return queryParams.stream()
                .filter(param -> param.getName().equalsIgnoreCase(paramName))
                .map(NameValuePair::getValue)
                .findFirst()
                .orElse("");
    }

Running java with JAVA_OPTS env variable has no effect

You can setup _JAVA_OPTIONS instead of JAVA_OPTS. This should work without $_JAVA_OPTIONS.

Use a JSON array with objects with javascript

@Swapnil Godambe It works for me if JSON.stringfy is removed. That is:

$(jQuery.parseJSON(dataArray)).each(function() {  
    var ID = this.id;
    var TITLE = this.Title;
});

How can I use break or continue within for loop in Twig template?

From docs TWIG docs:

Unlike in PHP, it's not possible to break or continue in a loop.

But still:

You can however filter the sequence during iteration which allows you to skip items.

Example 1 (for huge lists you can filter posts using slice, slice(start, length)):

{% for post in posts|slice(0,10) %}
    <h2>{{ post.heading }}</h2>
{% endfor %}

Example 2:

{% for post in posts if post.id < 10 %}
    <h2>{{ post.heading }}</h2>
{% endfor %}

You can even use own TWIG filters for more complexed conditions, like:

{% for post in posts|onlySuperPosts %}
    <h2>{{ post.heading }}</h2>
{% endfor %}

Can an AJAX response set a cookie?

For the record, be advised that all of the above is (still) true only if the AJAX call is made on the same domain. If you're looking into setting cookies on another domain using AJAX, you're opening a totally different can of worms. Reading cross-domain cookies does work, however (or at least the server serves them; whether your client's UA allows your code to access them is, again, a different topic; as of 2014 they do).

Read Excel File in Python

By using pandas we can read excel easily.

import pandas as pd 
from pandas import ExcelWriter
from pandas import ExcelFile 

DataF=pd.read_excel("Test.xlsx",sheet_name='Sheet1')

print("Column headings:")
print(DataF.columns)

Test at :https://repl.it Reference: https://pythonspot.com/read-excel-with-pandas/

Find Java classes implementing an interface

Package Level Annotations

I know this question has already been answered a long time ago but another solution to this problem is to use Package Level Annotations.

While its pretty hard to go find all the classes in the JVM its actually pretty easy to browse the package hierarchy.

Package[] ps = Package.getPackages();
for (Package p : ps) {
  MyAno a = p.getAnnotation(MyAno.class)
  // Recursively descend
}

Then just make your annotation have an argument of an array of Class. Then in your package-info.java for a particular package put the MyAno.

I'll add more details (code) if people are interested but most probably get the idea.

MetaInf Service Loader

To add to @erickson answer you can also use the service loader approach. Kohsuke has an awesome way of generating the the required META-INF stuff you need for the service loader approach:

http://weblogs.java.net/blog/kohsuke/archive/2009/03/my_project_of_t.html

PostgreSQL create table if not exists

I created a generic solution out of the existing answers which can be reused for any table:

CREATE OR REPLACE FUNCTION create_if_not_exists (table_name text, create_stmt text)
RETURNS text AS
$_$
BEGIN

IF EXISTS (
    SELECT *
    FROM   pg_catalog.pg_tables 
    WHERE    tablename  = table_name
    ) THEN
   RETURN 'TABLE ' || '''' || table_name || '''' || ' ALREADY EXISTS';
ELSE
   EXECUTE create_stmt;
   RETURN 'CREATED';
END IF;

END;
$_$ LANGUAGE plpgsql;

Usage:

select create_if_not_exists('my_table', 'CREATE TABLE my_table (id integer NOT NULL);');

It could be simplified further to take just one parameter if one would extract the table name out of the query parameter. Also I left out the schemas.

How to set environment variable or system property in spring tests?

You can initialize the System property in a static initializer:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:whereever/context.xml")
public class TestWarSpringContext {

    static {
        System.setProperty("myproperty", "foo");
    }

}

The static initializer code will be executed before the spring application context is initialized.

How to enable CORS in AngularJs

Answered by myself.

CORS angular js + restEasy on POST

Well finally I came to this workaround: The reason it worked with IE is because IE sends directly a POST instead of first a preflight request to ask for permission. But I still don't know why the filter wasn't able to manage an OPTIONS request and sends by default headers that aren't described in the filter (seems like an override for that only case ... maybe a restEasy thing ...)

So I created an OPTIONS path in my rest service that rewrites the reponse and includes the headers in the response using response header

I'm still looking for the clean way to do it if anybody faced this before.

When running UPDATE ... datetime = NOW(); will all rows updated have the same date/time?

They should have the same time, the update is supposed to be atomic, meaning that whatever how long it takes to perform, the action is supposed to occurs as if all was done at the same time.

If you're experiencing a different behaviour, it's time to change for another DBMS.

Smooth scroll to specific div on click

I took the Ned Rockson's version and adjusted it to allow upwards scrolls as well.

var smoothScroll = function(elementId) {
  var MIN_PIXELS_PER_STEP = 16;
  var MAX_SCROLL_STEPS = 30;
  var target = document.getElementById(elementId);
  var scrollContainer = target;
  do {
    scrollContainer = scrollContainer.parentNode;
    if (!scrollContainer) return;
    scrollContainer.scrollTop += 1;
  } while (scrollContainer.scrollTop === 0);

  var targetY = 0;
  do {
    if (target === scrollContainer) break;
    targetY += target.offsetTop;
  } while (target = target.offsetParent);

  var pixelsPerStep = Math.max(MIN_PIXELS_PER_STEP,
    Math.abs(targetY - scrollContainer.scrollTop) / MAX_SCROLL_STEPS);

  var isUp = targetY < scrollContainer.scrollTop;

  var stepFunc = function() {
    if (isUp) {
      scrollContainer.scrollTop = Math.max(targetY, scrollContainer.scrollTop - pixelsPerStep);
      if (scrollContainer.scrollTop <= targetY) {
        return;
      }
    } else {
        scrollContainer.scrollTop = Math.min(targetY, scrollContainer.scrollTop + pixelsPerStep);

      if (scrollContainer.scrollTop >= targetY) {
        return;
      }
    }

    window.requestAnimationFrame(stepFunc);
  };

  window.requestAnimationFrame(stepFunc);
};

Mailto on submit button

The full list of possible fields in the html based email-creating form:

  • subject
  • cc
  • bcc
  • body
<form action="mailto:[email protected]" method="GET">
  <input name="subject" type="text" /></br>
  <input name="cc" type="email" /><br />
  <input name="bcc" type="email" /><br />
  <textarea name="body"></textarea><br />
  <input type="submit" value="Send" />
</form>

https://codepen.io/garfunkel61/pen/oYGNGp

Datatable to html Table

public static string toHTML_Table(DataTable dt)
{
    if (dt.Rows.Count == 0) return ""; // enter code here

    StringBuilder builder = new StringBuilder();
    builder.Append("<html>");
    builder.Append("<head>");
    builder.Append("<title>");
    builder.Append("Page-");
    builder.Append(Guid.NewGuid());
    builder.Append("</title>");
    builder.Append("</head>");
    builder.Append("<body>");
    builder.Append("<table border='1px' cellpadding='5' cellspacing='0' ");
    builder.Append("style='border: solid 1px Silver; font-size: x-small;'>");
    builder.Append("<tr align='left' valign='top'>");
    foreach (DataColumn c in dt.Columns)
    {
        builder.Append("<td align='left' valign='top'><b>");
        builder.Append(c.ColumnName);
        builder.Append("</b></td>");
    }
    builder.Append("</tr>");
    foreach (DataRow r in dt.Rows)
    {
        builder.Append("<tr align='left' valign='top'>");
        foreach (DataColumn c in dt.Columns)
        {
            builder.Append("<td align='left' valign='top'>");
            builder.Append(r[c.ColumnName]);
            builder.Append("</td>");
        }
        builder.Append("</tr>");
    }
    builder.Append("</table>");
    builder.Append("</body>");
    builder.Append("</html>");

    return builder.ToString();
}

Converting characters to integers in Java

public class IntergerParser {

public static void main(String[] args){
String number = "+123123";
System.out.println(parseInt(number));
}

private static int parseInt(String number){
    char[] numChar = number.toCharArray();
    int intValue = 0;
    int decimal = 1;
    for(int index = numChar.length ; index > 0 ; index --){
        if(index == 1 ){
            if(numChar[index - 1] == '-'){
                return intValue * -1;
            } else if(numChar[index - 1] == '+'){
                return intValue;
            }
        }
        intValue = intValue + (((int)numChar[index-1] - 48) * (decimal));
        System.out.println((int)numChar[index-1] - 48+ " " + (decimal));
        decimal = decimal * 10;
    }
    return intValue;
}

JQuery $.ajax() post - data in a java servlet

To get the value from the servlet from POST command, you can follow the approach as explained on this post by using request.getParameter(key) format which will return the value you want.

Passing struct to function

You need to specify a type on person:

void addStudent(struct student person) {
...
}

Also, you can typedef your struct to avoid having to type struct every time you use it:

typedef struct student{
...
} student_t;

void addStudent(student_t person) {
...
}

Tricks to manage the available memory in an R session

If you really want to avoid the leaks, you should avoid creating any big objects in the global environment.

What I usually do is to have a function that does the job and returns NULL — all data is read and manipulated in this function or others that it calls.

How to downgrade php from 5.5 to 5.3

It is possible! Yes

In many cases, you might want to use XAMPP with a different PHP version than the one that comes preinstalled. You might do this to get the benefits of a newer version of PHP, or to reproduce bugs using an earlier version of PHP.

To use a different version of PHP with XAMPP, follow these steps:

  1. Download a binary build of the PHP version that you wish to use from the PHP website, and extract the contents of the compressed archive file to your XAMPP installation directory (usually, C:\xampp). Ensure that you give it a different directory name to avoid overwriting the existing PHP version. For example, in this tutorial, we’ll call the new directory C:\xampp\php5-6-0. NOTE : Ensure that the PHP build you download matches the Apache build (VC9 or VC11) in your XAMPP platform.

  2. Within the new directory, rename the php.ini-development file to php.ini. If you prefer to use production settings, you could instead rename the php.ini-production file to php.ini.

  3. Edit the httpd-xampp.conf file in the apache\conf\extra\ subdirectory of your XAMPP installation directory. Within this file, search for all instances of the old PHP directory path and replace them with the path to the new PHP directory created in Step 1. In particular, be sure to change the lines

    LoadFile "/xampp/php/php5ts.dll"
    LoadFile "/xampp/php/libpq.dll"
    LoadModule php5_module "/xampp/php/php5apache2_4.dll"

to

    LoadFile "/xampp/php5-6-0/php5ts.dll"
    LoadFile "/xampp/php5-6-0/libpq.dll"
    LoadModule php5_module "/xampp/php5-6-0/php5apache2_4.dll"

NOTE : Remember to adjust the file and directory paths above to reflect valid paths on your system.

  1. Restart your Apache server through the XAMPP control panel for your changes to take effect. The new version of PHP should now be active. To verify this, browse to the URL http://localhost/xampp/phpinfo.php, which displays the output of the phpinfo() command, and check the version number at the top of the page.

Ruby, remove last N characters from a string?

Dropping the last n characters is the same as keeping the first length - n characters.

Active Support includes String#first and String#last methods which provide a convenient way to keep or drop the first/last n characters:

require 'active_support/core_ext/string/access'

"foobarbaz".first(3)  # => "foo"
"foobarbaz".first(-3) # => "foobar"
"foobarbaz".last(3)   # => "baz"
"foobarbaz".last(-3)  # => "barbaz"

Console errors. Failed to load resource: net::ERR_INSECURE_RESPONSE

You are trying to get data from an https that does not have certificate. Change "https://" to "http://". Worked for me.

I need to convert an int variable to double

Either use casting as others have already said, or multiply one of the int variables by 1.0:

double firstSolution = ((1.0* b1 * a22 - b2 * a12) / (a11 * a22 - a12 * a21));

Selenium: Can I set any of the attribute value of a WebElement in Selenium?

If you're using the PageFactory pattern or already have a reference to your WebElement, then you probably want to set the attribute, using your existing reference to the WebElement. (Rather than doing a document.getElementById(...) in your javascript)

The following sample allows you to set the attribute, using your existing WebElement reference.

Code Snippet

import org.openqa.selenium.WebElement;
import org.openqa.selenium.remote.RemoteWebDriver;
import org.openqa.selenium.support.FindBy;

public class QuickTest {

    RemoteWebDriver driver;

    @FindBy(id = "foo")
    private WebElement username;

    public void exampleUsage(RemoteWebDriver driver) {
        setAttribute(username, "attr", "10");
        setAttribute(username, "value", "bar");
    }

    public void setAttribute(WebElement element, String attName, String attValue) {
        driver.executeScript("arguments[0].setAttribute(arguments[1], arguments[2]);", 
                element, attName, attValue);
    }
}

Launch an app on OS X with command line

You can launch apps using open:

open -a APP_YOU_WANT

This should open the application that you want.

C# - using List<T>.Find() with custom objects

Previous answers don't account for the fact that you've overloaded the equals operator and are using that to test for the sought element. In that case, your code would look like this:

list.Find(x => x == objectToFind);

Or, if you don't like lambda syntax, and have overriden object.Equals(object) or have implemented IEquatable<T>, you could do this:

list.Find(objectToFind.Equals);

Best approach to real time http streaming to HTML5 video client

Take a look at this solution. As I know, Flashphoner allows to play Live audio+video stream in the pure HTML5 page.

They use MPEG1 and G.711 codecs for playback. The hack is rendering decoded video to HTML5 canvas element and playing decoded audio via HTML5 audio context.

Minimum and maximum date

To augment T.J.'s answer, exceeding the min/max values generates an Invalid Date.

_x000D_
_x000D_
let maxDate = new Date(8640000000000000);_x000D_
let minDate = new Date(-8640000000000000);_x000D_
_x000D_
console.log(new Date(maxDate.getTime()).toString());_x000D_
console.log(new Date(maxDate.getTime() - 1).toString());_x000D_
console.log(new Date(maxDate.getTime() + 1).toString()); // Invalid Date_x000D_
_x000D_
console.log(new Date(minDate.getTime()).toString());_x000D_
console.log(new Date(minDate.getTime() + 1).toString());_x000D_
console.log(new Date(minDate.getTime() - 1).toString()); // Invalid Date
_x000D_
_x000D_
_x000D_

Print array to a file

I just wrote this function to output an array as text:

Should output nicely formatted array.

IMPORTANT NOTE:

Beware of user input.

This script was created for internal use.

If you intend to use this for public use you will need to add some additional data validation to prevent script injection.

This is not fool proof and should be used with trusted data only.

The following function will output something like:

$var = array(
  'primarykey' => array(
    'test' => array(
      'var' => array(
        1 => 99,
        2 => 500,
      ),
    ),
    'abc' => 'd',
  ),
);

here is the function (note: function is currently formatted for oop implementation.)

  public function outArray($array, $lvl=0){
    $sub = $lvl+1;
    $return = "";
    if($lvl==null){
      $return = "\t\$var = array(\n";  
    }
      foreach($array as $key => $mixed){
        $key = trim($key);
        if(!is_array($mixed)){
          $mixed = trim($mixed);
        }
        if(empty($key) && empty($mixed)){continue;}
        if(!is_numeric($key) && !empty($key)){
          if($key == "[]"){
            $key = null;
          } else {
            $key = "'".addslashes($key)."'";
          }
        }

        if($mixed === null){
          $mixed = 'null';
        } elseif($mixed === false){
          $mixed = 'false';
        } elseif($mixed === true){
          $mixed = 'true';
        } elseif($mixed === ""){
          $mixed = "''";
        } 

        //CONVERT STRINGS 'true', 'false' and 'null' TO true, false and null
        //uncomment if needed
        //elseif(!is_numeric($mixed) && !is_array($mixed) && !empty($mixed)){
        //  if($mixed != 'false' && $mixed != 'true' && $mixed != 'null'){
        //    $mixed = "'".addslashes($mixed)."'";
        //  }
        //}


        if(is_array($mixed)){
          if($key !== null){
            $return .= "\t".str_repeat("\t", $sub)."$key => array(\n";
            $return .= $this->outArray($mixed, $sub);
            $return .= "\t".str_repeat("\t", $sub)."),\n";
          } else {
            $return .= "\t".str_repeat("\t", $sub)."array(\n";
            $return .= $this->outArray($mixed, $sub);
            $return .= "\t".str_repeat("\t", $sub)."),\n";            
          }
        } else {
          if($key !== null){
            $return .= "\t".str_repeat("\t", $sub)."$key => $mixed,\n";
          } else {
            $return .= "\t".str_repeat("\t", $sub).$mixed.",\n";
          }
        }
    }
    if($lvl==null){
      $return .= "\t);\n";
    }
    return $return;
  }

Alternately you can use this script I also wrote a while ago:

This one is nice to copy and paste parts of an array.

( Would be near impossible to do that with serialized output )

Not the cleanest function but it gets the job done.

This one will output as follows:

$array['key']['key2'] = 'value';
$array['key']['key3'] = 'value2';
$array['x'] = 7;
$array['y']['z'] = 'abc';

Also take care for user input. Here is the code.

public static function prArray($array, $path=false, $top=true) {
    $data = "";
    $delimiter = "~~|~~";
    $p = null;
    if(is_array($array)){
      foreach($array as $key => $a){
        if(!is_array($a) || empty($a)){
          if(is_array($a)){
            $data .= $path."['{$key}'] = array();".$delimiter;
          } else {
            $data .= $path."['{$key}'] = \"".htmlentities(addslashes($a))."\";".$delimiter;
          }
        } else {
          $data .= self::prArray($a, $path."['{$key}']", false);
        }    
      }
    }
    if($top){
      $return = "";
      foreach(explode($delimiter, $data) as $value){
        if(!empty($value)){
          $return .= '$array'.$value."<br>";
        }
      };
      echo $return;
    }
    return $data;
  }

Get querystring from URL using jQuery

We do it this way...

String.prototype.getValueByKey = function (k) {
    var p = new RegExp('\\b' + k + '\\b', 'gi');
    return this.search(p) != -1 ? decodeURIComponent(this.substr(this.search(p) + k.length + 1).substr(0, this.substr(this.search(p) + k.length + 1).search(/(&|;|$)/))) : "";
};

ReactJS: setTimeout() not working?

Anytime we create a timeout we should s clear it on componentWillUnmount, if it hasn't fired yet.

      let myVar;
         const Component = React.createClass({

            getInitialState: function () {
                return {position: 0};    
            },

            componentDidMount: function () {
                 myVar = setTimeout(()=> this.setState({position: 1}), 3000)
            },

            componentWillUnmount: () => {
              clearTimeout(myVar);
             };
            render: function () {
                 return (
                    <div className="component">
                        {this.state.position}
                    </div>
                 ); 
            }

        });

ReactDOM.render(
    <Component />,
    document.getElementById('main')
);

Force decimal point instead of comma in HTML5 number input (client-side)

use the pattern

<input 
       type="number" 
       name="price"
       pattern="[0-9]+([\.,][0-9]+)?" 
       step="0.01"
       title="This should be a number with up to 2 decimal places."
>

good luck

How to copy a java.util.List into another java.util.List

There is another method with Java 8 in a null-safe way.

List<SomeBean> wsListCopy = Optional.ofNullable(wsList)
    .map(Collection::stream)
    .orElseGet(Stream::empty)
    .collect(Collectors.toList());

If you want to skip one element.

List<SomeBean> wsListCopy = Optional.ofNullable(wsList)
    .map(Collection::stream)
    .orElseGet(Stream::empty)
    .skip(1)
    .collect(Collectors.toList());

With Java 9+, the stream method of Optional can be used

Optional.ofNullable(wsList)
    .stream()
    .flatMap(Collection::stream)
    .collect(Collectors.toList())

HTTP redirect: 301 (permanent) vs. 302 (temporary)

When a search engine spider finds 301 status code in the response header of a webpage, it understands that this webpage no longer exists, it searches for location header in response pick the new URL and replace the indexed URL with the new one and also transfer pagerank.

So search engine refreshes all indexed URL that no longer exist (301 found) with the new URL, this will retain your old webpage traffic, pagerank and divert it to the new one (you will not lose you traffic of old webpage).

Browser: if a browser finds 301 status code then it caches the mapping of the old URL with the new URL, the client/browser will not attempt to request the original location but use the new location from now on unless the cache is cleared.

enter image description here

When a search engine spider finds 302 status for a webpage, it will only redirect temporarily to the new location and crawl both of the pages. The old webpage URL still exists in the search engine database and it always attempts to request the old location and crawl it. The client/browser will still attempt to request the original location.

enter image description here

Read more about how to implement it in asp.net c# and what is the impact on search engines - http://www.dotnetbull.com/2013/08/301-permanent-vs-302-temporary-status-code-aspnet-csharp-Implementation.html

Get SELECT's value and text in jQuery

You can do like this, to get the currently selected value:

$('#myDropdownID').val();

& to get the currently selected text:

$('#myDropdownID:selected').text();

How to set default Checked in checkbox ReactJS?

 <div className="form-group">
          <div className="checkbox">
            <label><input type="checkbox" value="" onChange={this.handleInputChange.bind(this)}  />Flagged</label>
            <br />
            <label><input type="checkbox" value=""  />Un Flagged</label>
          </div>
        </div

handleInputChange(event){

console.log("event",event.target.checked)   }

the Above handle give you the value of true or false upon checked or unChecked

Get resultset from oracle stored procedure

FYI as of Oracle 12c, you can do this:

CREATE OR REPLACE PROCEDURE testproc(n number)
AS
  cur SYS_REFCURSOR;
BEGIN
    OPEN cur FOR SELECT object_id,object_name from all_objects where rownum < n;
    DBMS_SQL.RETURN_RESULT(cur);
END;
/

EXEC testproc(3);

OBJECT_ID OBJECT_NAME                                                                                                                     
---------- ------------
100 ORA$BASE                                                                                                                        
116 DUAL                                                                                                                            

This was supposed to get closer to other databases, and ease migrations. But it's not perfect to me, for instance SQL developer won't display it nicely as a normal SELECT.

I prefer the output of pipeline functions, but they need more boilerplate to code.

more info: https://oracle-base.com/articles/12c/implicit-statement-results-12cr1

PHP Undefined Index

The checking of the presence of the member before assigning it is, in my opinion, quite ugly.

Kohana has a useful function to make selecting parameters simple.

You can make your own like so...

function arrayGet($array, $key, $default = NULL)
{
    return isset($array[$key]) ? $array[$key] : $default;
}

And then do something like...

$page = arrayGet($_GET, 'p', 1);

Xcode: Could not locate device support files

If you have XCode 8.1 and iOS 10.2, update XCode manually to 8.2.1. For some reason App Store didn't offer this update.

How to cherry-pick from a remote branch?

Adding remote repo (as "foo") from which we want to cherry-pick

$ git remote add foo git://github.com/foo/bar.git

Fetch their branches

$ git fetch foo

List their commits (this should list all commits in the fetched foo)

$ git log foo/master

Cherry-pick the commit you need

$ git cherry-pick 97fedac

Execute raw SQL using Doctrine 2

I got it to work by doing this, assuming you are using PDO.

//Place query here, let's say you want all the users that have blue as their favorite color
$sql = "SELECT name FROM user WHERE favorite_color = :color";

//set parameters 
//you may set as many parameters as you have on your query
$params['color'] = blue;


//create the prepared statement, by getting the doctrine connection
$stmt = $this->entityManager->getConnection()->prepare($sql);
$stmt->execute($params);
//I used FETCH_COLUMN because I only needed one Column.
return $stmt->fetchAll(PDO::FETCH_COLUMN);

You can change the FETCH_TYPE to suit your needs.

postgresql sequence nextval in schema

The quoting rules are painful. I think you want:

SELECT nextval('foo."SQ_ID"');

to prevent case-folding of SQ_ID.

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

Use empty():

std::string s;

if (s.empty())
    // nothing in s

How to split/partition a dataset into training and test datasets for, e.g., cross validation?

You may also consider stratified division into training and testing set. Startified division also generates training and testing set randomly but in such a way that original class proportions are preserved. This makes training and testing sets better reflect the properties of the original dataset.

import numpy as np  

def get_train_test_inds(y,train_proportion=0.7):
    '''Generates indices, making random stratified split into training set and testing sets
    with proportions train_proportion and (1-train_proportion) of initial sample.
    y is any iterable indicating classes of each observation in the sample.
    Initial proportions of classes inside training and 
    testing sets are preserved (stratified sampling).
    '''

    y=np.array(y)
    train_inds = np.zeros(len(y),dtype=bool)
    test_inds = np.zeros(len(y),dtype=bool)
    values = np.unique(y)
    for value in values:
        value_inds = np.nonzero(y==value)[0]
        np.random.shuffle(value_inds)
        n = int(train_proportion*len(value_inds))

        train_inds[value_inds[:n]]=True
        test_inds[value_inds[n:]]=True

    return train_inds,test_inds

y = np.array([1,1,2,2,3,3])
train_inds,test_inds = get_train_test_inds(y,train_proportion=0.5)
print y[train_inds]
print y[test_inds]

This code outputs:

[1 2 3]
[1 2 3]

Using OR in SQLAlchemy

This has been really helpful. Here is my implementation for any given table:

def sql_replace(self, tableobject, dictargs):

    #missing check of table object is valid
    primarykeys = [key.name for key in inspect(tableobject).primary_key]

    filterargs = []
    for primkeys in primarykeys:
        if dictargs[primkeys] is not None:
            filterargs.append(getattr(db.RT_eqmtvsdata, primkeys) == dictargs[primkeys])
        else:
            return

    query = select([db.RT_eqmtvsdata]).where(and_(*filterargs))

    if self.r_ExecuteAndErrorChk2(query)[primarykeys[0]] is not None:
        # update
        filter = and_(*filterargs)
        query = tableobject.__table__.update().values(dictargs).where(filter)
        return self.w_ExecuteAndErrorChk2(query)

    else:
        query = tableobject.__table__.insert().values(dictargs)
        return self.w_ExecuteAndErrorChk2(query)

# example usage
inrow = {'eqmtvs_id': eqmtvsid, 'datetime': dtime, 'param_id': paramid}

self.sql_replace(tableobject=db.RT_eqmtvsdata, dictargs=inrow)

Remove the legend on a matplotlib figure

If you want to plot a Pandas dataframe and want to remove the legend, add legend=None as parameter to the plot command.

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

df2 = pd.DataFrame(np.random.randn(10, 5))
df2.plot(legend=None)
plt.show()

Column standard deviation R

Use colSds function from matrixStats library.

library(matrixStats)
set.seed(42)
M <- matrix(rnorm(40),ncol=4)
colSds(M)

[1] 0.8354488 1.6305844 1.1560580 1.1152688

How to debug on a real device (using Eclipse/ADT)

in devices which has Android 4.3 and above you should follow these steps:

How to enable Developer Options:

Launch Settings menu.
Find the open the ‘About Device’ menu.
Scroll down to ‘Build Number’.
Next, tap on the ‘build number’ section seven times.
After the seventh tap you will be told that you are now a developer.
Go back to Settings menu and the Developer Options menu will now be displayed.

In order to enable the USB Debugging you will simply need to open Developer Options, scroll down and tick the box that says ‘USB Debugging’. That’s it.

How do I create an array of strings in C?

If the strings are static, you're best off with:

const char *my_array[] = {"eenie","meenie","miney"};

While not part of basic ANSI C, chances are your environment supports the syntax. These strings are immutable (read-only), and thus in many environments use less overhead than dynamically building a string array.

For example in small micro-controller projects, this syntax uses program memory rather than (usually) more precious ram memory. AVR-C is an example environment supporting this syntax, but so do most of the other ones.

Load vs. Stress testing

The terms "stress testing" and "load testing" are often used interchangeably by software test engineers but they are really quite different.

Stress testing

In Stress testing we tries to break the system under test by overwhelming its resources or by taking resources away from it (in which case it is sometimes called negative testing). The main purpose behind this madness is to make sure that the system fails and recovers gracefully -- this quality is known as recoverability. OR Stress testing is the process of subjecting your program/system under test (SUT) to reduced resources and then examining the SUT’s behavior by running standard functional tests. The idea of this is to expose problems that do not appear under normal conditions.For example, a multi-threaded program may work fine under normal conditions but under conditions of reduced CPU availability, timing issues will be different and the SUT will crash. The most common types of system resources reduced in stress testing are CPU, internal memory, and external disk space. When performing stress testing, it is common to call the tools which reduce these three resources EatCPU, EatMem, and EatDisk respectively.

While on the other hand Load Testing

In case of Load testing Load testing is the process of subjecting your SUT to heavy loads, typically by simulating multiple users( Using Load runner), where "users" can mean human users or virtual/programmatic users. The most common example of load testing involves subjecting a Web-based or network-based application to simultaneous hits by thousands of users. This is generally accomplished by a program which simulates the users. There are two main purposes of load testing: to determine performance characteristics of the SUT, and to determine if the SUT "breaks" gracefully or not.

In the case of a Web site, you would use load testing to determine how many users your system can handle and still have adequate performance, and to determine what happens with an extreme load — will the Web site generate a "too busy" message for users, or will the Web server crash in flames?

Android Linear Layout - How to Keep Element At Bottom Of View?

You will have to expand one of your upper views to fill the remaining space by setting android:layout_weight="1" on it. This will push your last view down to the bottom.

Here is a brief sketch of what I mean:

<LinearLayout android:orientation="vertical">
    <View/>
    <View android:layout_weight="1"/>
    <View/>
    <View android:id="@+id/bottom"/>
</LinearLayout>

where each of the child view heights is "wrap_content" and everything else is "fill_parent".

How to make program go back to the top of the code instead of closing

You can easily do it with loops, there are two types of loops

For Loops:

for i in range(0,5):
    print 'Hello World'

While Loops:

count = 1
while count <= 5:
    print 'Hello World'
    count += 1

Each of these loops print "Hello World" five times

android on Text Change Listener

A bit late of a answer, but here is a reusable solution:

/**
 * An extension of TextWatcher which stops further callbacks being called as 
 * a result of a change happening within the callbacks themselves.
 */
public abstract class EditableTextWatcher implements TextWatcher {

    private boolean editing;

    @Override
    public final void beforeTextChanged(CharSequence s, int start, 
                                                    int count, int after) {
        if (editing)
            return;

        editing = true;
        try {
            beforeTextChange(s, start, count, after);
        } finally {
            editing = false;
        }
    }

    protected abstract void beforeTextChange(CharSequence s, int start, 
                                                     int count, int after);

    @Override
    public final void onTextChanged(CharSequence s, int start, 
                                                int before, int count) {
        if (editing)
            return;

        editing = true;
        try {
            onTextChange(s, start, before, count);
        } finally {
            editing = false;
        }
    }

    protected abstract void onTextChange(CharSequence s, int start, 
                                            int before, int count);

    @Override
    public final void afterTextChanged(Editable s) {
        if (editing)
            return;

        editing = true;
        try {
            afterTextChange(s);
        } finally {
            editing = false;
        }
    }

    public boolean isEditing() {
        return editing;
    }

    protected abstract void afterTextChange(Editable s);
}

So when the above is used, any setText() calls happening within the TextWatcher will not result in the TextWatcher being called again:

/**
 * A setText() call in any of the callbacks below will not result in TextWatcher being 
 * called again.
 */
public class MyTextWatcher extends EditableTextWatcher {

    @Override
    protected void beforeTextChange(CharSequence s, int start, int count, int after) {
    }

    @Override
    protected void onTextChange(CharSequence s, int start, int before, int count) {
    }

    @Override
    protected void afterTextChange(Editable s) {
    }
}

What possibilities can cause "Service Unavailable 503" error?

We recently encountered this error, root cause turned out to be an expired SSL cert on the IIS server. The Load Balancer (infront of our web tier) found the SSL expired, and instead of handling the HTTP traffic over to one of the IIS servers, started showing this error. So basically IIS unable to server requests, for a totally different reason :)

Invoking JavaScript code in an iframe from the parent page

If the iFrame's target and the containing document are on a different domain, the methods previously posted might not work, but there is a solution:

For example, if document A contains an iframe element that contains document B, and script in document A calls postMessage() on the Window object of document B, then a message event will be fired on that object, marked as originating from the Window of document A. The script in document A might look like:

var o = document.getElementsByTagName('iframe')[0];
o.contentWindow.postMessage('Hello world', 'http://b.example.org/');

To register an event handler for incoming events, the script would use addEventListener() (or similar mechanisms). For example, the script in document B might look like:

window.addEventListener('message', receiver, false);
function receiver(e) {
  if (e.origin == 'http://example.com') {
    if (e.data == 'Hello world') {
      e.source.postMessage('Hello', e.origin);
    } else {
      alert(e.data);
    }
  }
}

This script first checks the domain is the expected domain, and then looks at the message, which it either displays to the user, or responds to by sending a message back to the document which sent the message in the first place.

via http://dev.w3.org/html5/postmsg/#web-messaging

ImportError: No Module named simplejson

For anyone coming across this years later:

TL;DR check your pip version (2 vs 3)

I had this same issue and it was not fixed by running pip install simplejson despite pip insisting that it was installed. Then I realized that I had both python 2 and python 3 installed.

> python -V
Python 2.7.12
> pip -V
pip 9.0.1 from /usr/local/lib/python3.5/site-packages (python 3.5)

Installing with the correct version of pip is as easy as using pip2:

> pip2 install simplejson

and then python 2 can import simplejson fine.

Program does not contain a static 'Main' method suitable for an entry point

Maybe the "Output type" in properties->Application of the project must be a "Class Library" instead of console or windows application.

Align DIV's to bottom or baseline

I had something similar and got it to work by effectively adding some padding-top to the child.

I'm sure some of the other answers here would get to the solution, but I couldn't get them to easily work after a lot of time; I instead ended up with the padding-top solution which is elegant in its simplicity, but seems kind of hackish to me (not to mention the pixel value it sets would probably depend on the parent height).

Responsive design with media query : screen size?

Take a look at this... http://getbootstrap.com/

For big websites I use Bootstrap and sometimes (for simple websites) I create all the style with some @mediaqueries. It's very simple, just think all the code in percentage.

.container {
max-width: 1200px;
width: 100%;
margin: 0 auto;
}

Inside the container, your structure must have widths in percentage like this...

.col-1 {
width: 40%;
float: left;
}

.col-2 {
width: 60%;
float: left;
}

@media screen and (max-width: 320px) {
.col-1, .col-2 { width: 100%; }
}

In some simple interfaces, if you start to develop the project in this way, you will have great chances to have a fully responsive site using break points only to adjust the flow of objects.

XAMPP installation on Win 8.1 with UAC Warning

There's nothing to be worried upon for this. Like other servers, install xampp somewhere outside of the default Program Files folder of Windows. It shall work fine.

I previously had wamp server installed on my machine and i never understood why wamp server installs itself outside of the default directory. Xampp cleared this, now i have both the servers lying outside the Program Files folder and are running fine.

How to compute the sum and average of elements in an array?

On evergreen browsers you can use arrow functions avg = [1,2,3].reduce((a,b) => (a+b);

Running it 100,000 times, the time difference between the for loop approach and reduce is negligible.

_x000D_
_x000D_
s=Date.now();for(i=0;i<100000;i++){ n=[1,2,3]; a=n.reduce((a,b) => (a+b)) / n.length };_x000D_
console.log("100k reduce took " + (Date.now()-s) + "ms.");_x000D_
_x000D_
s=Date.now();for(i=0;i<100000;i++){n=[1,2,3]; nl=n.length; a=0; for(j=nl-1;j>0;j--){a=a+n[j];} a/nl };_x000D_
console.log("100k for loop took " + (Date.now()-s) + "ms.");_x000D_
_x000D_
s=Date.now();for(i=0;i<1000000;i++){n=[1,2,3]; nl=n.length; a=0; for(j=nl-1;j>0;j--){a=a+n[j];} a/nl };_x000D_
console.log("1M for loop took " + (Date.now()-s) + "ms.");_x000D_
_x000D_
s=Date.now();for(i=0;i<1000000;i++){ n=[1,2,3]; a=n.reduce((a,b) => (a+b)) / n.length };_x000D_
console.log("1M reduce took " + (Date.now()-s) + "ms.");_x000D_
_x000D_
/* _x000D_
 * RESULT on Chrome 51_x000D_
 * 100k reduce took 26ms._x000D_
 * 100k for loop took 35ms._x000D_
 * 10M for loop took 126ms._x000D_
 * 10M reduce took 209ms._x000D_
 */
_x000D_
_x000D_
_x000D_

Getting the text that follows after the regex match

Your regex "sentence(.*)" is right. To retrieve the contents of the group in parenthesis, you would call:

Pattern p = Pattern.compile( "sentence(.*)" );
Matcher m = p.matcher( "some lame sentence that is awesome" );
if ( m.find() ) {
   String s = m.group(1); // " that is awesome"
}

Note the use of m.find() in this case (attempts to find anywhere on the string) and not m.matches() (would fail because of the prefix "some lame"; in this case the regex would need to be ".*sentence(.*)")

Failed to load ApplicationContext from Unit Test: FileNotFound

For me, I was missing @ActiveProfile at my test class

@ActiveProfiles("sandbox")
class MyTestClass...

How can I check if character in a string is a letter? (Python)

This works:

word = str(input("Enter string:"))
notChar = 0
isChar = 0
for char in word:
    if not char.isalpha():
        notChar += 1
    else:
        isChar += 1
print(isChar, " were letters; ", notChar, " were not letters.")

Is there a performance difference between CTE , Sub-Query, Temporary Table or Table Variable?

There is no rule. I find CTEs more readable, and use them unless they exhibit some performance problem, in which case I investigate the actual problem rather than guess that the CTE is the problem and try to re-write it using a different approach. There is usually more to the issue than the way I chose to declaratively state my intentions with the query.

There are certainly cases when you can unravel CTEs or remove subqueries and replace them with a #temp table and reduce duration. This can be due to various things, such as stale stats, the inability to even get accurate stats (e.g. joining to a table-valued function), parallelism, or even the inability to generate an optimal plan because of the complexity of the query (in which case breaking it up may give the optimizer a fighting chance). But there are also cases where the I/O involved with creating a #temp table can outweigh the other performance aspects that may make a particular plan shape using a CTE less attractive.

Quite honestly, there are way too many variables to provide a "correct" answer to your question. There is no predictable way to know when a query may tip in favor of one approach or another - just know that, in theory, the same semantics for a CTE or a single subquery should execute the exact same. I think your question would be more valuable if you present some cases where this is not true - it may be that you have discovered a limitation in the optimizer (or discovered a known one), or it may be that your queries are not semantically equivalent or that one contains an element that thwarts optimization.

So I would suggest writing the query in a way that seems most natural to you, and only deviate when you discover an actual performance problem the optimizer is having. Personally I rank them CTE, then subquery, with #temp table being a last resort.

How do I add a placeholder on a CharField in Django?

You can use this code to add placeholder attr for every TextInput field in you form. Text for placeholders will be taken from model field labels.

class PlaceholderDemoForm(forms.ModelForm):
    def __init__(self, *args, **kwargs):
        super(PlaceholderDemoForm, self).__init__(*args, **kwargs)
        for field_name in self.fields:
            field = self.fields.get(field_name)  
            if field:
                if type(field.widget) in (forms.TextInput, forms.DateInput):
                    field.widget = forms.TextInput(attrs={'placeholder': field.label})

    class Meta:
        model = DemoModel

Linq where clause compare only date value without time value

&& x.DateTimeValueColumn <= DateTime.Now

This is supported so long as your schema is correct

&& x.DateTimeValueColumn.Value.Date <=DateTime.Now

Declaring a python function with an array parameters and passing an array argument to the function call?

I guess I'm unclear about what the OP was really asking for... Do you want to pass the whole array/list and operate on it inside the function? Or do you want the same thing done on every value/item in the array/list. If the latter is what you wish I have found a method which works well.

I'm more familiar with programming languages such as Fortran and C, in which you can define elemental functions which operate on each element inside an array. I finally tracked down the python equivalent to this and thought I would repost the solution here. The key is to 'vectorize' the function. Here is an example:

def myfunc(a,b):
    if (a>b): return a
    else: return b
vecfunc = np.vectorize(myfunc)
result=vecfunc([[1,2,3],[5,6,9]],[7,4,5])
print(result)

Output:

[[7 4 5]
 [7 6 9]]

Changing the current working directory in Java?

If you run your legacy program with ProcessBuilder, you will be able to specify its working directory.

How do you create a Marker with a custom icon for google maps API v3?

marker = new google.maps.Marker({
    map:map,
    // draggable:true,
    // animation: google.maps.Animation.DROP,
    position: new google.maps.LatLng(59.32522, 18.07002),
    icon: 'http://cdn.com/my-custom-icon.png' // null = default icon
  });

How to get a Docker container's IP address from the host

I use this simple way

docker exec -it <container id or name> hostname -i

e.g

ubuntu@myhost:~$ docker exec -it 3d618ac670fe hostname -i
10.0.1.5

Tomcat in Intellij Idea Community Edition

You can use tomcat plugin with gradle. For more information, you here.

apply plugin: 'tomcat'

dependencies {
    classpath 'org.gradle.api.plugins:gradle-tomcat-plugin:1.2.4'
}

[compileJava, compileTestJava]*.options*.encoding = 'UTF-8'

[tomcatRun, tomcatRunWar, tomcatStop]*.stopPort = 8090
[tomcatRun, tomcatRunWar, tomcatStop]*.stopKey = 'stfu'
tomcatRunWar.contextPath = "/$rootProject.name"
tomcatRunWar.ajpPort = 8000

if (checkBeforeRun.toBoolean()) {
    tomcatRunWar { dependsOn += ['check'] }
}

rmagick gem install "Can't find Magick-config"

On Mac OS X sudo port install ImageMagick turned out to work fine to fix the gem install rmagick problem . I just didn't know that it worked fine because rvm during installation blew away my .bash_profile contents which included MacPort's addition of /opt/local/bin to PATH. I put back /opt/local/bin into PATH in my .bash_profile and then my gem install rmagick then succeeded.

Bootstrap 3: how to make head of dropdown link clickable in navbar

Most of the above solutions are not mobile friendly.

The solution I am proposing detects if its not touch device and that the navbar-toggle (hamburger menu) is not visible and makes the parent menu item revealing submenu on hover and and follow its link on click

Also makes tne margin-top 0 because the gap between the navbar and the menu in some browser will not let you hover to the subitems

_x000D_
_x000D_
$(function(){_x000D_
    function is_touch_device() {_x000D_
        return 'ontouchstart' in window        // works on most browsers _x000D_
        || navigator.maxTouchPoints;       // works on IE10/11 and Surface_x000D_
    };_x000D_
_x000D_
    if(!is_touch_device() && $('.navbar-toggle:hidden')){_x000D_
      $('.dropdown-menu', this).css('margin-top',0);_x000D_
      $('.dropdown').hover(function(){ _x000D_
          $('.dropdown-toggle', this).trigger('click').toggleClass("disabled"); _x000D_
      });   _x000D_
    }_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
_x000D_
<ul id="nav" class="nav nav-pills clearfix right" role="tablist">_x000D_
    <li><a href="#">menuA</a></li>_x000D_
    <li><a href="#">menuB</a></li>_x000D_
    <li class="dropdown"><a href="#" class="dropdown-toggle" data-toggle="dropdown">menuC</a>_x000D_
        <ul id="products-menu" class="dropdown-menu clearfix" role="menu">_x000D_
            <li><a href="">A</a></li>_x000D_
            <li><a href="">B</a></li>_x000D_
            <li><a href="">C</a></li>_x000D_
            <li><a href="">D</a></li>_x000D_
        </ul>_x000D_
    </li>_x000D_
    <li><a href="#">menuD</a></li>_x000D_
    <li><a href="#">menuE</a></li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

_x000D_
_x000D_
$(function(){_x000D_
  $("#nav .dropdown").hover(_x000D_
    function() {_x000D_
      $('#products-menu.dropdown-menu', this).stop( true, true ).fadeIn("fast");_x000D_
      $(this).toggleClass('open');_x000D_
    },_x000D_
    function() {_x000D_
      $('#products-menu.dropdown-menu', this).stop( true, true ).fadeOut("fast");_x000D_
      $(this).toggleClass('open');_x000D_
    });_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
_x000D_
<ul id="nav" class="nav nav-pills clearfix right" role="tablist">_x000D_
    <li><a href="#">menuA</a></li>_x000D_
    <li><a href="#">menuB</a></li>_x000D_
    <li class="dropdown"><a href="#" class="dropdown-toggle" data-toggle="dropdown">menuC</a>_x000D_
        <ul id="products-menu" class="dropdown-menu clearfix" role="menu">_x000D_
            <li><a href="">A</a></li>_x000D_
            <li><a href="">B</a></li>_x000D_
            <li><a href="">C</a></li>_x000D_
            <li><a href="">D</a></li>_x000D_
        </ul>_x000D_
    </li>_x000D_
    <li><a href="#">menuD</a></li>_x000D_
    <li><a href="#">menuE</a></li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

What are Transient and Volatile Modifiers?

Volatile means other threads can edit that particular variable. So the compiler allows access to them.

http://www.javamex.com/tutorials/synchronization_volatile.shtml

Transient means that when you serialize an object, it will return its default value on de-serialization

http://www.geekinterview.com/question_details/2

How to remove last n characters from every element in the R vector

The same may be achieved with the stringi package:

library('stringi')
char_array <- c("foo_bar","bar_foo","apple","beer")
a <- data.frame("data"=char_array, "data2"=1:4)
(a$data <- stri_sub(a$data, 1, -4)) # from the first to the last but 4th char
## [1] "foo_" "bar_" "ap"   "b" 

Install dependencies globally and locally using package.json

This is a bit old but I ran into the requirement so here is the solution I came up with.

The Problem:

Our development team maintains many .NET web application products we are migrating to AngularJS/Bootstrap. VS2010 does not lend itself easily to custom build processes and my developers are routinely working on multiple releases of our products. Our VCS is Subversion (I know, I know. I'm trying to move to Git but my pesky marketing staff is so demanding) and a single VS solution will include several separate projects. I needed my staff to have a common method for initializing their development environment without having to install the same Node packages (gulp, bower, etc.) several times on the same machine.

TL;DR:

  1. Need "npm install" to install the global Node/Bower development environment as well as all locally required packages for a .NET product.

  2. Global packages should be installed only if not already installed.

  3. Local links to global packages must be created automatically.

The Solution:

We already have a common development framework shared by all developers and all products so I created a NodeJS script to install the global packages when needed and create the local links. The script resides in "....\SharedFiles" relative to the product base folder:

/*******************************************************************************
* $Id: npm-setup.js 12785 2016-01-29 16:34:49Z sthames $
* ==============================================================================
* Parameters: 'links' - Create links in local environment, optional.
* 
* <p>NodeJS script to install common development environment packages in global
* environment. <c>packages</c> object contains list of packages to install.</p>
* 
* <p>Including 'links' creates links in local environment to global packages.</p>
* 
* <p><b>npm ls -g --json</b> command is run to provide the current list of 
* global packages for comparison to required packages. Packages are installed 
* only if not installed. If the package is installed but is not the required 
* package version, the existing package is removed and the required package is 
* installed.</p>.
*
* <p>When provided as a "preinstall" script in a "package.json" file, the "npm
* install" command calls this to verify global dependencies are installed.</p>
*******************************************************************************/
var exec = require('child_process').exec;
var fs   = require('fs');
var path = require('path');

/*---------------------------------------------------------------*/
/* List of packages to install and 'from' value to pass to 'npm  */
/* install'. Value must match the 'from' field in 'npm ls -json' */
/* so this script will recognize a package is already installed. */
/*---------------------------------------------------------------*/
var packages = 
  {
  "bower"                      :                      "[email protected]", 
  "event-stream"               :               "[email protected]",
  "gulp"                       :                       "[email protected]",
  "gulp-angular-templatecache" : "[email protected]",
  "gulp-clean"                 :                 "[email protected]", 
  "gulp-concat"                :                "[email protected]",
  "gulp-debug"                 :                 "[email protected]",
  "gulp-filter"                :                "[email protected]",
  "gulp-grep-contents"         :         "[email protected]",
  "gulp-if"                    :                    "[email protected]", 
  "gulp-inject"                :                "[email protected]", 
  "gulp-minify-css"            :            "[email protected]",
  "gulp-minify-html"           :           "[email protected]",
  "gulp-minify-inline"         :         "[email protected]",
  "gulp-ng-annotate"           :           "[email protected]",
  "gulp-processhtml"           :           "[email protected]",
  "gulp-rev"                   :                   "[email protected]",
  "gulp-rev-replace"           :           "[email protected]",
  "gulp-uglify"                :                "[email protected]",
  "gulp-useref"                :                "[email protected]",
  "gulp-util"                  :                  "[email protected]",
  "lazypipe"                   :                   "[email protected]",
  "q"                          :                          "[email protected]",
  "through2"                   :                   "[email protected]",

  /*---------------------------------------------------------------*/
  /* fork of 0.2.14 allows passing parameters to main-bower-files. */
  /*---------------------------------------------------------------*/
  "bower-main"                 : "git+https://github.com/Pyo25/bower-main.git" 
  }

/*******************************************************************************
* run */
/**
* Executes <c>cmd</c> in the shell and calls <c>cb</c> on success. Error aborts.
* 
* Note: Error code -4082 is EBUSY error which is sometimes thrown by npm for 
* reasons unknown. Possibly this is due to antivirus program scanning the file 
* but it sometimes happens in cases where an antivirus program does not explain 
* it. The error generally will not happen a second time so this method will call 
* itself to try the command again if the EBUSY error occurs.
* 
* @param  cmd  Command to execute.
* @param  cb   Method to call on success. Text returned from stdout is input.
*******************************************************************************/
var run = function(cmd, cb)
  {
  /*---------------------------------------------*/
  /* Increase the maxBuffer to 10MB for commands */
  /* with a lot of output. This is not necessary */
  /* with spawn but it has other issues.         */
  /*---------------------------------------------*/
  exec(cmd, { maxBuffer: 1000*1024 }, function(err, stdout)
    {
    if      (!err)                   cb(stdout);
    else if (err.code | 0 == -4082) run(cmd, cb);
    else throw err;
    });
  };

/*******************************************************************************
* runCommand */
/**
* Logs the command and calls <c>run</c>.
*******************************************************************************/
var runCommand = function(cmd, cb)
  {
  console.log(cmd);
  run(cmd, cb);
  }

/*******************************************************************************
* Main line
*******************************************************************************/
var doLinks  = (process.argv[2] || "").toLowerCase() == 'links';
var names    = Object.keys(packages);
var name;
var installed;
var links;

/*------------------------------------------*/
/* Get the list of installed packages for   */
/* version comparison and install packages. */
/*------------------------------------------*/
console.log('Configuring global Node environment...')
run('npm ls -g --json', function(stdout)
  {
  installed = JSON.parse(stdout).dependencies || {};
  doWhile();
  });

/*--------------------------------------------*/
/* Start of asynchronous package installation */
/* loop. Do until all packages installed.     */
/*--------------------------------------------*/
var doWhile = function()
  {
  if (name = names.shift())
    doWhile0();
  }

var doWhile0 = function()
  {
  /*----------------------------------------------*/
  /* Installed package specification comes from   */
  /* 'from' field of installed packages. Required */
  /* specification comes from the packages list.  */
  /*----------------------------------------------*/
  var current  = (installed[name] || {}).from;
  var required =   packages[name];

  /*---------------------------------------*/
  /* Install the package if not installed. */
  /*---------------------------------------*/
  if (!current)
    runCommand('npm install -g '+required, doWhile1);

  /*------------------------------------*/
  /* If the installed version does not  */
  /* match, uninstall and then install. */
  /*------------------------------------*/
  else if (current != required)
    {
    delete installed[name];
    runCommand('npm remove -g '+name, function() 
      {
      runCommand('npm remove '+name, doWhile0);
      });
    }

  /*------------------------------------*/
  /* Skip package if already installed. */
  /*------------------------------------*/
  else
    doWhile1();
  };

var doWhile1 = function()
  {
  /*-------------------------------------------------------*/
  /* Create link to global package from local environment. */
  /*-------------------------------------------------------*/
  if (doLinks && !fs.existsSync(path.join('node_modules', name)))
    runCommand('npm link '+name, doWhile);
  else
    doWhile();
  };

Now if I want to update a global tool for our developers, I update the "packages" object and check in the new script. My developers check it out and either run it with "node npm-setup.js" or by "npm install" from any of the products under development to update the global environment. The whole thing takes 5 minutes.

In addition, to configure the environment for the a new developer, they must first only install NodeJS and GIT for Windows, reboot their computer, check out the "Shared Files" folder and any products under development, and start working.

The "package.json" for the .NET product calls this script prior to install:

{ 
"name"                    : "Books",
"description"             : "Node (npm) configuration for Books Database Web Application Tools",
"version"                 : "2.1.1",
"private"                 : true,
"scripts":
  {
  "preinstall"            : "node ../../SharedFiles/npm-setup.js links",
  "postinstall"           : "bower install"
  },
"dependencies": {}
}

Notes

  • Note the script reference requires forward slashes even in a Windows environment.

  • "npm ls" will give "npm ERR! extraneous:" messages for all packages locally linked because they are not listed in the "package.json" "dependencies".

Edit 1/29/16

The updated npm-setup.js script above has been modified as follows:

  • Package "version" in var packages is now the "package" value passed to npm install on the command line. This was changed to allow for installing packages from somewhere other than the registered repository.

  • If the package is already installed but is not the one requested, the existing package is removed and the correct one installed.

  • For reasons unknown, npm will periodically throw an EBUSY error (-4082) when performing an install or link. This error is trapped and the command re-executed. The error rarely happens a second time and seems to always clear up.

In Javascript, how to conditionally add a member to an object?

This is the most succinct solution I can come up with:

var a = {};
conditionB && a.b = 5;
conditionC && a.c = 5;
conditionD && a.d = 5;
// ...

How to escape comma and double quote at same time for CSV file?

If you're using CSVWriter. Check that you don't have the option

.withQuotechar(CSVWriter.NO_QUOTE_CHARACTER)

When I removed it the comma was showing as expected and not treating it as new column

How to align a div to the top of its parent but keeping its inline-block behaviour?

Or you could just add some content to the div and use inline-table

TypeError: 'int' object is not subscriptable

Just to be clear, all the answers so far are correct, but the reasoning behind them is not explained very well.

The sumall variable is not yet a string. Parentheticals will not convert to a string (e.g. summ = (int(birthday[0])+int(birthday[1])) still returns an integer. It looks like you most likely intended to type str((int(sumall[0])+int(sumall[1]))), but forgot to. The reason the str() function fixes everything is because it converts anything in it compatible to a string.

How to create standard Borderless buttons (like in the design guideline mentioned)?

Use the below code in your xml file. Use android:background="#00000000" to have the transparent color.

<Button
   android:id="@+id/btnLocation"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:background="#00000000"
   android:text="@string/menu_location"
   android:paddingRight="7dp"
/>

Convert SVG image to PNG with PHP

I do not know of a standalone PHP / Apache solution, as this would require a PHP library that can read and render SVG images. I'm not sure such a library exists - I don't know any.

ImageMagick is able to rasterize SVG files, either through the command line or the PHP binding, IMagick, but seems to have a number of quirks and external dependencies as shown e.g. in this forum thread. I think it's still the most promising way to go, it's the first thing I would look into if I were you.

How to change package name of an Android Application

  1. In your Android studio , at project panel , there is gear icon "Click on it".
  2. Uncheck the Compact Empty Middle Packages
  3. Now the package directory has been broken up i.e individual directories.
  4. Select the directory you want to rename.
  5. Right click on that particular directory.
  6. Select refactor and then rename option.
  7. The dialog box has been open up,rename it.
  8. After putting new name, click on Refactor.
  9. Then click on Do Refactor at bottom.
  10. Then android studio will update all changes.
  11. Now open build.gradle file and update the applicationId & sync it.
  12. Now go to manifest file and rename the package.
  13. Rebuild your Project.
  14. You are done :)

Spark specify multiple column conditions for dataframe join

There is a Spark column/expression API join for such case:

Leaddetails.join(
    Utm_Master, 
    Leaddetails("LeadSource") <=> Utm_Master("LeadSource")
        && Leaddetails("Utm_Source") <=> Utm_Master("Utm_Source")
        && Leaddetails("Utm_Medium") <=> Utm_Master("Utm_Medium")
        && Leaddetails("Utm_Campaign") <=> Utm_Master("Utm_Campaign"),
    "left"
)

The <=> operator in the example means "Equality test that is safe for null values".

The main difference with simple Equality test (===) is that the first one is safe to use in case one of the columns may have null values.

How does the ARM architecture differ from x86?

ARM is a RISC (Reduced Instruction Set Computing) architecture while x86 is a CISC (Complex Instruction Set Computing) one.

The core difference between those in this aspect is that ARM instructions operate only on registers with a few instructions for loading and saving data from / to memory while x86 can operate directly on memory as well. Up until v8 ARM was a native 32 bit architecture, favoring four byte operations over others.

So ARM is a simpler architecture, leading to small silicon area and lots of power save features while x86 becoming a power beast in terms of both power consumption and production.

About question on "Is the x86 Architecture specially designed to work with a keyboard while ARM expects to be mobile?". x86 isn't specially designed to work with a keyboard neither ARM for mobile. However again because of the core architectural choices actually x86 also has instructions to work directly with IO while ARM has not. However with specialized IO buses like USBs, need for such features are also disappearing.

If you need a document to quote, this is what Cortex-A Series Programmers Guide (4.0) tells about differences between RISC and CISC architectures:

An ARM processor is a Reduced Instruction Set Computer (RISC) processor.

Complex Instruction Set Computer (CISC) processors, like the x86, have a rich instruction set capable of doing complex things with a single instruction. Such processors often have significant amounts of internal logic that decode machine instructions to sequences of internal operations (microcode).

RISC architectures, in contrast, have a smaller number of more general purpose instructions, that might be executed with significantly fewer transistors, making the silicon cheaper and more power efficient. Like other RISC architectures, ARM cores have a large number of general-purpose registers and many instructions execute in a single cycle. It has simple addressing modes, where all load/store addresses can be determined from register contents and instruction fields.

ARM company also provides a paper titled Architectures, Processors, and Devices Development Article describing how those terms apply to their bussiness.

An example comparing instruction set architecture:

For example if you would need some sort of bytewise memory comparison block in your application (generated by compiler, skipping details), this is how it might look like on x86

repe cmpsb         /* repeat while equal compare string bytewise */

while on ARM shortest form might look like (without error checking etc.)

top:
ldrb r2, [r0, #1]! /* load a byte from address in r0 into r2, increment r0 after */
ldrb r3, [r1, #1]! /* load a byte from address in r1 into r3, increment r1 after */
subs r2, r3, r2    /* subtract r2 from r3 and put result into r2      */
beq  top           /* branch(/jump) if result is zero                 */

which should give you a hint on how RISC and CISC instruction sets differ in complexity.

FIFO class in Java

You're looking for any class that implements the Queue interface, excluding PriorityQueue and PriorityBlockingQueue, which do not use a FIFO algorithm.

Probably a LinkedList using add (adds one to the end) and removeFirst (removes one from the front and returns it) is the easiest one to use.

For example, here's a program that uses a LinkedList to queue and retrieve the digits of PI:

import java.util.LinkedList;

class Test {
    public static void main(String args[]) {
        char arr[] = {3,1,4,1,5,9,2,6,5,3,5,8,9};
        LinkedList<Integer> fifo = new LinkedList<Integer>();

        for (int i = 0; i < arr.length; i++)
            fifo.add (new Integer (arr[i]));

        System.out.print (fifo.removeFirst() + ".");
        while (! fifo.isEmpty())
            System.out.print (fifo.removeFirst());
        System.out.println();
    }
} 

Alternatively, if you know you only want to treat it as a queue (without the extra features of a linked list), you can just use the Queue interface itself:

import java.util.LinkedList;
import java.util.Queue;

class Test {
    public static void main(String args[]) {
        char arr[] = {3,1,4,1,5,9,2,6,5,3,5,8,9};
        Queue<Integer> fifo = new LinkedList<Integer>();

        for (int i = 0; i < arr.length; i++)
            fifo.add (new Integer (arr[i]));

        System.out.print (fifo.remove() + ".");
        while (! fifo.isEmpty())
            System.out.print (fifo.remove());
        System.out.println();
    }
}

This has the advantage of allowing you to replace the underlying concrete class with any class that provides the Queue interface, without having to change the code too much.

The basic changes are to change the type of fifo to a Queue and to use remove() instead of removeFirst(), the latter being unavailable for the Queue interface.

Calling isEmpty() is still okay since that belongs to the Collection interface of which Queue is a derivative.

Resize an Array while keeping current elements in Java?

Sorry, but at this time is not possible resize arrays, and may be never will be.

So my recommendation, is to think more to find a solution that allow you get from the beginning of the process, the size of the arrays that you will requiere. This often will implicate that your code need a little more time (lines) to run, but you will save a lot of memory resources.

How can I pretty-print JSON using node.js?

what about this?

console.table(object)

sample

Return a 2d array from a function

Whatever changes you would make in function will persist.So there is no need to return anything.You can pass 2d array and change it whenever you will like.

  void MakeGridOfCounts(int Grid[][6])
    {
      cGrid[6][6] = {{0, }, {0, }, {0, }, {0, }, {0, }, {0, }};

    }

or

void MakeGridOfCounts(int Grid[][6],int answerArray[][6])
    {
     ....//do the changes in the array as you like they will reflect in main... 
    }

Stop jQuery .load response from being cached

For PHP, add this line to your script which serves the information you want:

header("cache-control: no-cache");

or, add a unique variable to the query string:

"/portal/?f=searchBilling&x=" + (new Date()).getTime()

Nth max salary in Oracle

These queries will also work:

Workaround 1)

SELECT ename, sal 
FROM Emp e1 WHERE n-1 = (SELECT COUNT(DISTINCT sal) 
                         FROM Emp e2 WHERE e2.sal > e1.sal)

Workaround 2) using row_num function.

SELECT * 
FROM ( 
   SELECT e.*, ROW_NUMBER() OVER (ORDER BY sal DESC) rn FROM Emp e 
) WHERE rn = n;

Workaround 3 ) using rownum pseudocolumn

Select MAX(SAL) 
from (
   Select * 
   from (
      Select * 
      from EMP 
      order by SAL Desc
   ) where rownum <= n
)

Parse JSON from HttpURLConnection object

The JSON string will just be the body of the response you get back from the URL you have called. So add this code

...
BufferedReader in = new BufferedReader(new InputStreamReader(
                            conn.getInputStream()));
String inputLine;
while ((inputLine = in.readLine()) != null) 
    System.out.println(inputLine);
in.close();

That will allow you to see the JSON being returned to the console. The only missing piece you then have is using a JSON library to read that data and provide you with a Java representation.

Here's an example using JSON-LIB

PHP Change Array Keys

$prefix = '_';
$arr = array_combine(
    array_map(function($v) use ($prefix){
       return $prefix.$v;
    }, array_keys($arr)),
    array_values($arr)
);

Comparing two vectors in an if statement

I'd probably use all.equal and which to get the information you want. It's not recommended to use all.equal in an if...else block for some reason, so we wrap it in isTRUE(). See ?all.equal for more:

foo <- function(A,B){
  if (!isTRUE(all.equal(A,B))){
    mismatches <- paste(which(A != B), collapse = ",")
    stop("error the A and B does not match at the following columns: ", mismatches )
  } else {
    message("Yahtzee!")
  }
}

And in use:

> foo(A,A)
Yahtzee!
> foo(A,B)
Yahtzee!
> foo(A,C)
Error in foo(A, C) : 
  error the A and B does not match at the following columns: 2,4

I am getting "java.lang.ClassNotFoundException: com.google.gson.Gson" error even though it is defined in my classpath

Click on Deployment Assembly ( right above Java Build Path that you show as active ) and make sure that you see json-lib-2.4-jdk15.jar there.

Usually, you should add it to your build path and export it from your project. Once it's exported you will see the WTP warning that it's not a part of the deployment. Choose the Quick Fix option and add it to your deployment path.

How to parse JSON string in Typescript

Typescript is (a superset of) javascript, so you just use JSON.parse as you would in javascript:

let obj = JSON.parse(jsonString);

Only that in typescript you can have a type to the resulting object:

interface MyObj {
    myString: string;
    myNumber: number;
}

let obj: MyObj = JSON.parse('{ "myString": "string", "myNumber": 4 }');
console.log(obj.myString);
console.log(obj.myNumber);

(code in playground)

How do I clone a specific Git branch?

git checkout -b <branch-name> <origin/branch_name>

for example in my case:

 git branch -a
* master
  origin/HEAD
  origin/enum-account-number
  origin/master
  origin/rel_table_play
  origin/sugarfield_customer_number_show_c

So to create a new branch based on my enum-account-number branch I do:

git checkout -b enum-account-number origin/enum-account-number

After you hit return the following happens:

Branch enum-account-number set up to track remote branch refs/remotes/origin/enum-account-number.
Switched to a new branch "enum-account-number"

How do I create JavaScript array (JSON format) dynamically?

Our array of objects

var someData = [
   {firstName: "Max", lastName: "Mustermann", age: 40},
   {firstName: "Hagbard", lastName: "Celine", age: 44},
   {firstName: "Karl", lastName: "Koch", age: 42},
];

with for...in

var employees = {
    accounting: []
};

for(var i in someData) {    

    var item = someData[i];   

    employees.accounting.push({ 
        "firstName" : item.firstName,
        "lastName"  : item.lastName,
        "age"       : item.age 
    });
}

or with Array.prototype.map(), which is much cleaner:

var employees = {
    accounting: []
};

someData.map(function(item) {        
   employees.accounting.push({ 
        "firstName" : item.firstName,
        "lastName"  : item.lastName,
        "age"       : item.age 
    });
}

What is a smart pointer and when should I use one?

A smart pointer is like a regular (typed) pointer, like "char*", except when the pointer itself goes out of scope then what it points to is deleted as well. You can use it like you would a regular pointer, by using "->", but not if you need an actual pointer to the data. For that, you can use "&*ptr".

It is useful for:

  • Objects that must be allocated with new, but that you'd like to have the same lifetime as something on that stack. If the object is assigned to a smart pointer, then they will be deleted when the program exits that function/block.

  • Data members of classes, so that when the object is deleted all the owned data is deleted as well, without any special code in the destructor (you will need to be sure the destructor is virtual, which is almost always a good thing to do).

You may not want to use a smart pointer when:

  • ... the pointer shouldn't actually own the data... i.e., when you are just using the data, but you want it to survive the function where you are referencing it.
  • ... the smart pointer isn't itself going to be destroyed at some point. You don't want it to sit in memory that never gets destroyed (such as in an object that is dynamically allocated but won't be explicitly deleted).
  • ... two smart pointers might point to the same data. (There are, however, even smarter pointers that will handle that... that is called reference counting.)

See also:

How do I look inside a Python object?

I'm surprised no one's mentioned help yet!

In [1]: def foo():
   ...:     "foo!"
   ...:

In [2]: help(foo)
Help on function foo in module __main__:

foo()
    foo!

Help lets you read the docstring and get an idea of what attributes a class might have, which is pretty helpful.

Package structure for a Java project?

The way i usually have my hierarchy of folder-

  • Project Name
    • src
    • bin
    • tests
    • libs
    • docs

EF Core add-migration Build Failed

I got the same error. There were no errors during the build proccess. I closed the Visual Studio and it worked.

must appear in the GROUP BY clause or be used in an aggregate function

I recently run into this problem, when trying to count using case when, and found that changing the order of the which and count statements fixes the problem:

SELECT date(dateday) as pick_day,
COUNT(CASE WHEN (apples = 'TRUE' OR oranges 'TRUE') THEN fruit END)  AS fruit_counter

FROM pickings

GROUP BY 1

Instead of using - in the latter, where I got errors that apples and oranges should appear in aggregate functions

CASE WHEN ((apples = 'TRUE' OR oranges 'TRUE') THEN COUNT(*) END) END AS fruit_counter

Get real path from URI, Android KitKat new storage access framework

I had the exact same problem. I need the filename so to be able to upload it to a website.

It worked for me, if I changed the intent to PICK. This was tested in AVD for Android 4.4 and in AVD for Android 2.1.

Add permission READ_EXTERNAL_STORAGE :

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

Change the Intent :

Intent i = new Intent(
  Intent.ACTION_PICK,
  android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI
  );
startActivityForResult(i, 66453666);

/* OLD CODE
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(
  Intent.createChooser( intent, "Select Image" ),
  66453666
  );
*/

I did not have to change my code the get the actual path:

// Convert the image URI to the direct file system path of the image file
 public String mf_szGetRealPathFromURI(final Context context, final Uri ac_Uri )
 {
     String result = "";
     boolean isok = false;

     Cursor cursor = null;
      try { 
        String[] proj = { MediaStore.Images.Media.DATA };
        cursor = context.getContentResolver().query(ac_Uri,  proj, null, null, null);
        int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        result = cursor.getString(column_index);
        isok = true;
      } finally {
        if (cursor != null) {
          cursor.close();
        }
      }

      return isok ? result : "";
 }