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Django filter versus get for single object?
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get() is provided specifically for this case. Use it.
Option 2 is almost precisely how the get() method is actually implemented in Django, so there should be no "performance" difference (and the fact that you're thinking about it indicates you're violating...
Mathematical functions in Swift
How do I use mathematical functions like sqrt() , floor() , round() , sin() , etc?
6 Answers
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PHP append one array to another (not array_push or +)
...g like:
$merge = $a + $b;
// $merge now equals array('a','b')
Will not work, because the + operator does not actually merge them. If they $a has the same keys as $b, it won't do anything.
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How does the Windows Command Interpreter (CMD.EXE) parse scripts?
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We performed experiments to investigate the grammar of batch scripts. We also investigated differences between batch and command line mode.
Batch Line Parser:
Here is a brief overview of phases in the batch file line parser:
Phas...
Is char signed or unsigned by default?
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The book is wrong. The standard does not specify if plain char is signed or unsigned.
In fact, the standard defines three distinct types: char, signed char, and unsigned char. If you #include <limits.h> and then look at CHAR_MIN, you can find out if plain char is signed or unsigned (if CHA...
How to permanently set $PATH on Linux/Unix? [closed]
I'm trying to add a directory to my path so it will always be in my Linux path. I've tried:
24 Answers
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Why does string::compare return an int?
...y does string::compare return an int instead of a smaller type like short or char ? My understanding is that this method only returns -1, 0 or 1.
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Rolling or sliding window iterator?
... need a rolling window (aka sliding window) iterable over a sequence/iterator/generator. Default Python iteration can be considered a special case, where the window length is 1. I'm currently using the following code. Does anyone have a more Pythonic, less verbose, or more efficient method for do...
Checking from shell script if a directory contains files
From a shell script, how do I check if a directory contains files?
26 Answers
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How to check for an undefined or null variable in JavaScript?
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You have to differentiate between cases:
Variables can be undefined or undeclared. You'll get an error if you access an undeclared variable in any context other than typeof.
if(typeof someUndeclaredVar == whatever) // works
if(someUndeclaredVar) // throws error
A variable that has been de...