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Is calculating an MD5 hash less CPU intensive than SHA family functions?
...ng an MD5 hash less CPU intensive than SHA-1 or SHA-2 on "standard" laptop x86 hardware? I'm interested in general information, not specific to a certain chip.
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Using wget to recursively fetch a directory with arbitrary files in it
...ursive, of course), otherwise it will follow the link in the directory index on my site to the parent directory. So the command would look like this:
wget --recursive --no-parent http://example.com/configs/.vim/
To avoid downloading the auto-generated index.html files, use the -R/--reject option:...
PHP Replace last occurrence of a String in a String?
...ctions. (But did they have to change the name?)
– alexis
Dec 5 '18 at 20:55
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Check if passed argument is file or directory in Bash
I'm trying to write an extremely simple script in Ubuntu which would allow me to pass it either a filename or a directory, and be able to do something specific when it's a file, and something else when it's a directory. The problem I'm having is when the directory name, or probably files too, has s...
Cartesian product of multiple arrays in JavaScript
...overly complicated, most of them take 20 lines of code or even more.
This example uses just two lines of vanilla JavaScript, no lodash, underscore or other libraries:
let f = (a, b) => [].concat(...a.map(a => b.map(b => [].concat(a, b))));
let cartesian = (a, b, ...c) => b ? cartesian(f(...
Pandas dataframe get first row of each group
...If you need id as column:
>>> df.groupby('id').first().reset_index()
id value
0 1 first
1 2 first
2 3 first
3 4 second
4 5 first
5 6 first
6 7 fourth
To get n first records, you can use head():
>>> df.groupby('id').head(2).reset_index(drop=True)
...
Convert hex string to int in Python
How do I convert a hex string to an int in Python?
12 Answers
12
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correct way to use super (argument passing)
...s following Python's Super Considered Harmful , and went to test out his examples.
3 Answers
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How can I implement prepend and append with regular JavaScript?
...ild)
Inserts the node newChild as a child of parentNode before the
existing child node refChild. (Returns newChild.)
If refChild is null, newChild is added at the end of the list of
children. Equivalently, and more readably, use
parentNode.appendChild(newChild).
...
Filter rows which contain a certain string
...lready posted by the @latemail in the comments above. You can use regular expressions for the second and subsequent arguments of filter like this:
dplyr::filter(df, !grepl("RTB",TrackingPixel))
Since you have not provided the original data, I will add a toy example using the mtcars data set. Imag...