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Only mkdir if it does not exist [duplicate]
...
One-liner requires an extra ;: if [ ! -d directory ]; then mkdir directory; fi
– sdgfsdh
Jun 13 '17 at 15:35
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C#: Difference between List and Collection (CA1002, Do not expose generic lists) [duplicate]
...lity in mind it's very flexible. If in the future you decide you need some extra feature in the collection you can just extend it without any change to the public interface of the class. If you had used a list, you would have had to change it to a collection which means it would have broken all of t...
Create boolean column in MySQL with false as default value?
... for true / false it gives and accepts the true / false values without any extra code.
ALTER TABLE `itemcategory` ADD `aaa` ENUM('false', 'true') NOT NULL DEFAULT 'false'
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Writing a new line to file in PHP (line feed)
... 4.3.10 and PHP 5.0.2. See the manual posting:
Using this will save you extra coding on cross platform developments.
IE.
$data = 'some data'.PHP_EOL;
$fp = fopen('somefile', 'a');
fwrite($fp, $data);
If you looped through this twice you would see in 'somefile':
some data
some data
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Source code highlighting in LaTeX
...bble=2,
frame=lines,
framesep=2mm]{csharp}
string title = "This is a Unicode π in the sky"
/*
Defined as $\pi=\lim_{n\to\infty}\frac{P_n}{d}$ where $P$ is the perimeter
of an $n$-sided regular polygon circumscribing a
circle of diameter $d$.
*/
const doub...
Compare two DataFrames and output their differences side-by-side
... in the score column):
import sys
if sys.version_info[0] < 3:
from StringIO import StringIO
else:
from io import StringIO
DF1 = StringIO("""id Name score isEnrolled Comment
111 Jack 2.17 True "He was late to class"
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Why does pylint object to single character variable names?
...f the variable or in the function / method prototype:
bool check_modality(string a, Mode b, OptionList c) {
ModalityChecker v = build_checker(a, b);
return v.check_option(c);
}
In Python, you don't get this information, so if you write:
def check_modality(a, b, c):
v = build_checker(...
Defining and using a variable in batch file
...e referenced with %location %. If that’s not what you want, remove the extra space(s) in the definition.
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Why are my balls disappearing? [closed]
...tyX);
ball2.nextY = (ball2.nextY += ball2.velocityY);
You don't need the extra assignments, and can just use the += operator alone:
ball1.nextX += ball1.velocityX;
ball1.nextY += ball1.velocityY;
ball2.nextX += ball2.velocityX;
ball2.nextY += ball2.velocityY;
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Should I use “hasClass” before “addClass”? [duplicate]
...l because jQuery will also always check from within .addClass(). It's just extra work.
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