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In Python how should I test if a variable is None, True or False
... == 1) == True
38.1 ns ± 0.116 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)
In [2]: %timeit (1 == 1) is True
33.7 ns ± 0.141 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)
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Index (zero based) must be greater than or equal to zero
... edited Apr 22 at 17:45
jt000
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answered Sep 28 '17 at 14:01
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Why can't (or doesn't) the compiler optimize a predictable addition loop into a multiplication?
...arraySize; ++c)
if (data[c] >= 128)
for (int i = 0; i < 100000; ++i)
sum += data[c];
into
for (int c = 0; c < arraySize; ++c)
if (data[c] >= 128)
sum += 100000 * data[c];
because the latter could lead to overflow of signed integers where the forme...
How do I write a short literal in C++?
... you trace one of the suffixes, you'll see that e.g. ""ui8 is defined as '\000', which is essentially '\0'.
– Nikita
Jan 28 '17 at 19:03
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Easier way to create circle div than using an image?
...idth: 50px;
height: 50px;
background: #ccc;
border: 3px solid #000;
}
.type3 {
width: 500px;
height: 500px;
background: aqua;
border: 30px solid blue;
}
HTML:
<div class="circleBase type1"></div>
<div class="circleBase type2"></div><div clas...
PDO Prepared Inserts multiple rows in single query
...y slow. My test file to create the $data array has 28 cols and is about 80,000 lines. The final script took 41s to complete.
Using array_push() to create $insert_values instead of array_merge() resulted in a 100X speed up with execution time of 0.41s.
The problematic array_merge():
$insert_values...
Convert Array to Object
...the initial object that was created. Running a JSPerf test on an array of 1000 elements, creating a new object every time is 1,000 times slower than mutating the existing object. jsperf.com/…
– romellem
Nov 26 '19 at 17:00
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Why were pandas merges in python faster than data.table merges in R in 2012?
...ssue in data.table when the number of unique strings (levels) is large: 10,000.
Does Rprof() reveal most of the time spent in the call sortedmatch(levels(i[[lc]]), levels(x[[rc]])? This isn't really the join itself (the algorithm), but a preliminary step.
Recent efforts have gone into allowing ch...
Convert an ISO date to the date format yyyy-mm-dd in JavaScript
...an think of is that if your code deals with geoloical-scale time at least 8000 years in the future, your code could break because the format will be YYYYY-MM-DD in the year 10000. To avoid this you could split on the T character instead. (See en.wikipedia.org/wiki/Year_10,000_problem)
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What are valid values for the id attribute in HTML?
... insist that any application a vendor develops runs in IE6. This is for 30,000 users. Heck, if we could just get them to update their browsers on all those desktops, it might just help the unemployment rate.
– Karl
Sep 13 '12 at 13:50
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