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What does the star operator mean, in a function call?
...
s = sum(1, 2)
The double star ** does the same, onlm>y m> using a dictionarm>y m> m>and m> thus named arguments:
values = { 'a': 1, 'b': 2 }
s = sum(**values)
m>Y m>ou can also combine:
def sum(a, b, c, d):
return a + b + c + d
values1 = (1, 2)
values2 = { 'c': 10, 'd': 15 }
s = sum(*values1, **values2)
w...
How to test if a string is JSON or not?
I have a simple AJAX call, m>and m> the server will return either a JSON string with useful data or an error message string produced bm>y m> the PHP function mm>y m>sql_error() . How can I test whether this data is a JSON string or the error message.
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Whm>y m> is there huge performance hit in 2048x2048 versus 2047x2047 arram>y m> multiplication?
...L is alwam>y m>s power of 2.
The six comes from fact that 2^6 == 64 bm>y m>tes is stm>and m>ard size of cache line.
Now what does this mean? Well it means that if I have address X m>and m> address m>Y m> m>and m>
(X >> 6) - (m>Y m> >> 6) is divisible bm>y m> L (i.e. some large power of 2), them>y m> will be stored in the same ca...
Center a popup window on screen?
...: It will also work on windows that aren't maxed out to the screen's width m>and m> height now thanks to @Frost!
If m>y m>ou're on dual monitor, the window will center horizontallm>y m>, but not verticallm>y m>... use this function to account for that.
const popupCenter = ({url, title, w, h}) => {
// Fixes dua...
Can't find a “not equal” css attribute selector
...v foo="z">ZZZ</div>
div:not([foo='']) will select both the first m>and m> second div elements. If m>y m>ou onlm>y m> want div elements that have an attribute foo that is set to an emptm>y m> string, m>y m>ou should use:
div[foo]:not([foo=''])
If m>y m>ou want all elements with attribute foo that is neither m>y m> nor z, m>y m>...
Linux bash: Multiple variable assignment
...good point, though I'm not sure if one needs the return status of echo commm>and m> :-) I think at the time of writing the answer bash supporting this sm>y m>ntax was less common (as in installed bm>y m> default), though I'm not 100% sure.
– Michael Krelin - hacker
Oct 21 '15...
Converting RGB to gram>y m>scale/intensitm>y m>
... from RGB to gram>y m>scale, it is said that specific weights to channels R, G, m>and m> B ought to be applied. These weights are: 0.2989, 0.5870, 0.1140.
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How do I perform an IF…THEN in an SQL SELECT?
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The CASE statement is the closest to IF in SQL m>and m> is supported on all versions of SQL Server.
SELECT CAST(
CASE
WHEN Obsolete = 'N' or InStock = 'm>Y m>'
THEN 1
ELSE 0
END AS bit) as Saleable,...
How to execute multi-line statements within Pm>y m>thon's own debugger (PDB)
... It seems the same can be achieved using the pdb interact commm>and m> (as I learned from this bug tracker message).
– gerrit
Jun 11 '14 at 15:15
3
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Elegant wam>y m> to invert a map in Scala
Learning Scala currentlm>y m> m>and m> needed to invert a Map to do some inverted value->kem>y m> lookups. I was looking for a simple wam>y m> to do this, but came up with onlm>y m>:
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