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What does .SD stand for in data.table in R
... may help you see what .SD is:
DT[ , .SD[ , paste(x, v, sep="", collapse="_")], by=y]
# y V1
# 1: 1 a1_b3_c5
# 2: 3 a2_b4_c6
Basically, the by=y statement breaks the original data.table into these two sub-data.tables
DT[ , print(.SD), by=y]
# <1st sub-data.table, called '.SD' while i...
Parsing XML with namespace in Python via 'ElementTree'
...
@Jon: register_namespace only influences serialisation, not search.
– Martijn Pieters♦
Aug 20 '14 at 7:10
5
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How to capture no file for fs.readFileSync()?
... good code practices here!
const content = await readFileAsync(path.join(__dirname, filePath), {
encoding: 'utf8'
})
return content;
}
Later can use this async function with try/catch from any other function:
const anyOtherFun = async () => {
try {
const fileContent = await rea...
PHP global in functions
...n fn()
{
global $foo; // never ever use that
$a = SOME_CONSTANT // do not use that
$b = Foo::SOME_CONSTANT; // do not use that unless self::
$c = $GLOBALS['foo']; // incl. any other superglobal ($_GET, …)
$d = Foo::bar(); // any static call, in...
Read logcat programmatically within application
...7.
*/
public class Logger {
// http://www.java2s.com/Tutorial/Java/0040__Data-Type/SimpleDateFormat.htm
private static final String ANDROID_LOG_TIME_FORMAT = "MM-dd kk:mm:ss.SSS";
private static SimpleDateFormat logCatDate = new SimpleDateFormat(ANDROID_LOG_TIME_FORMAT);
public static Str...
adding multiple entries to a HashMap at once in one statement
... 2016) as follow:
Map<String, Integer> cities = Map.of("Brussels", 1_139000, "Cardiff", 341_000);
The var-args case for Map is a little bit harder, you need to have both keys and values, but in Java, methods can’t have two var-args parameters. So the general case is handled by taking a va...
Is there some way to PUSH data from web server to browser?
...
Yes, what you're looking for is COMET http://en.wikipedia.org/wiki/Comet_(programming). Other good Google terms to search for are AJAX-push and reverse-ajax.
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Dealing with “java.lang.OutOfMemoryError: PermGen space” error
.../usr/share/tomcat6/bin/setenv.sh and added the following line to that: JAVA_OPTS="-Xms256m -Xmx512m -XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled" - Restarted tomcat using: sudo /etc/init.d/tomcat6 start
– sami
Dec 10 '10 at 14:44
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Prepend a level to a pandas MultiIndex
...to the columns by adding axis=1, since the df.columns doesn't have the "set_index" method like the index, which always bugs me.
– Rutger Kassies
Feb 10 '17 at 12:32
2
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Java equivalent to #region in C#
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With Android Studio, try this:
//region VARIABLES
private String _sMyVar1;
private String _sMyVar2;
//endregion
Careful : no blank line after //region ...
And you will get:
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