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Why does multiprocessing use only a single core after I import numpy?
...er here.
It turns out that certain Python modules (numpy, scipy, tables, pandas, skimage...) mess with core affinity on import. As far as I can tell, this problem seems to be specifically caused by them linking against multithreaded OpenBLAS libraries.
A workaround is to reset the task affinity us...
Does the join order matter in SQL?
Disregarding performance, will I get the same result from query A and B below? How about C and D?
4 Answers
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Get element inside element by class and ID - JavaScript
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Might be good to edit this answer and change .innerHtml to .textContent for the security benefit of copy/paste coders.
– codescribblr
Sep 24 '18 at 18:00
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Why is the Android emulator so slow? How can we speed up the Android emulator? [closed]
I have got a 2.67 GHz Celeron processor, and 1.21 GB of RAM on a x86 Windows XP Professional machine.
77 Answer...
Select multiple records based on list of Id's with linq
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Contains() will handle that equality check on each id value if you use it as I've written in the answer. You don't have to explicitly write == anywhere when you're trying to compare the items of one set (the array) against another (the datab...
Setting CSS pseudo-class rules from JavaScript
...0);
document.styleSheets[0].rules[0].style.backgroundColor= 'red';
Older and minor browsers are likely not to support either syntax. Dynamic stylesheet-fiddling is rarely done because it's quite annoying to get right, rarely needed, and historically troublesome.
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npm command to uninstall or prune unused packages in Node.js
... remove modules not listed in package.json.
From npm help prune:
This command removes "extraneous" packages. If a package name is provided, then only packages matching one of the supplied names are removed.
Extraneous packages are packages that are not listed on the parent package's dependencies l...
Which is the preferred way to concatenate a string in Python?
...ring to a string variable is to use + or +=. This is because it's readable and fast. They are also just as fast, which one you choose is a matter of taste, the latter one is the most common. Here are timings with the timeit module:
a = a + b:
0.11338996887207031
a += b:
0.11040496826171875
Howeve...
python: how to identify if a variable is an array or a scalar
...supports a tuple of classes, check type(x) in (..., ...) should be avoided and is unnecessary.
You may also wanna check not isinstance(x, (str, unicode))
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Converting an array of objects to ActiveRecord::Relation
... ActiveRecord::Relation since a Relation is just a builder for a SQL query and its methods do not operate on actual data.
However, if what you want is a relation then:
for ActiveRecord 3.x, don’t call all and instead call scoped, which will give back a Relation which represents the same records...