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Hide Utility Class Constructor : Utility classes should not have a public or default constructor
...c final class FilePathHelper {
private FilePathHelper() {
//not called
}
}
This prevents the default parameter-less constructor from being used elsewhere in your code. Additionally, you can make the class final, so that it can't be extended in subclasses, which is a best practice for ...
When is null or undefined used in JavaScript? [duplicate]
...
The DOM methods getElementById(), nextSibling(), childNodes[n], parentNode() and so on return null (defined but having no value) when the call does not return a node object.
The property is defined, but the object it refers to does not exist.
This is one of ...
How can I connect to a Tor hidden service using cURL in PHP?
...
You need to set option CURLOPT_PROXYTYPE to CURLPROXY_SOCKS5_HOSTNAME, which sadly wasn't defined in old PHP versions, circa pre-5.6; if you have earlier in but you can explicitly use its value, which is equal to 7:
curl_setopt($ch, CURLOPT_PROXYTYPE, 7...
Launch an app on OS X with command line
I want to launch an app on OSX from a script. I need pass it command line arguments. Unfortunately, open doesn't accept command line args.
...
Format numbers to strings in Python
...}.html'.format(**d)
'http://xxx.yyy.zzz/user/42.html'
Like Python 2.6+, all Python 3 releases (so far) understand how to do both. I shamelessly ripped this stuff straight out of my hardcore Python intro book and the slides for the Intro+Intermediate Python courses I offer from time-to-time. :-)
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How to use `subprocess` command with pipes
I want to use subprocess.check_output() with ps -A | grep 'process_name' .
I tried various solutions but so far nothing worked. Can someone guide me how to do it?
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What's the difference between `=` and `
...as the operator = is only allowed at the top level (e.g., in the complete expression typed at the command prompt) or as one of the subexpressions in a braced list of expressions.
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Pairwise crossproduct in Python [duplicate]
...,5,6]
>>> itertools.product(a,b)
<itertools.product object at 0x10049b870>
>>> list(itertools.product(a,b))
[(1, 4), (1, 5), (1, 6), (2, 4), (2, 5), (2, 6), (3, 4), (3, 5), (3, 6)]
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Error in if/while (condition) {: missing Value where TRUE/FALSE needed
...where TRUE/FALSE needed
To test whether an object is missing use is.na(x) rather than x == NA.
See also the related errors:
Error in if/while (condition) { : argument is of length zero
Error in if/while (condition) : argument is not interpretable as logical
if (NULL) {}
## Error in if (NUL...
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