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What is the purpose of setting a key in data.table?
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A key is basically an index into a dataset, which allows for very fast and efficient sort, filter, and join operations. These are probably the best reasons to use data tables instead of data frames (the syntax for using data tables is also much mo...
Random color generator
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You can remove .split('') call. String already have Array indexer.
– ujeenator
Jul 27 '15 at 6:08
4
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OS X: equivalent of Linux's wget
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Use curl;
curl http://127.0.0.1:8000 -o index.html
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Is a Python list guaranteed to have its elements stay in the order they are inserted in?
...g structure of an Array is still a special case of an object with numbered indexes, so it's not a contradiction to your statement, just an interesting tidbit, I thought.
– Multihunter
Dec 8 '16 at 21:09
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How do I change an HTML selected option using JavaScript?
...).options[0].selected = 'selected';
}
/**
* Set Select Box Selection By Index
* @param eid Element ID
* @param eindx Element Index
*/
function setSelectBoxByIndex(eid, eindx) {
document.getElementById(eid).getElementsByTagName('option')[eindx].selected = 'selected';
//or
document....
Remove the first character of a string
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deleting a char:
def del_char(string, indexes):
'deletes all the indexes from the string and returns the new one'
return ''.join((char for idx, char in enumerate(string) if idx not in indexes))
it deletes all the chars that are in indexes; you can use...
Bash command to sum a column of numbers [duplicate]
...actly what I was looking for, here's summing a particular column (column 2 indexed from zero): perl -nle '$s += (split)[2]; END { print $s }' foo.txt or using pipes: cat foo.txt | perl -nle '$s += (split)[2]; END { print $s }'.
– Ben
May 14 '14 at 13:17
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When should I use Arrow functions in ECMAScript 6?
...render = function () {
var book = this;
this.$pages.each(function (index) {
var $page = $(this);
book.draw(book.currentPage + index, $page);
});
};
We must use function in order for each to bind this dynamically. We can't use an arrow function here.
Dealing with multip...
Phonegap Cordova installation Windows
...GapCordova 3.3.0 Documentation
http://docs.phonegap.com/en/3.3.0/guide_cli_index.md.html#The%20Command-Line%20Interface
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Warning the user/local/mysql/data directory is not owned by the mysql user
...restart.
Reference: https://coolestguidesontheplanet.com/get-apache-mysql-php-phpmyadmin-working-osx-10-10-yosemite/
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