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scala vs java, performance and memory? [closed]
....length()>2 && mapping.get(s) != null) b.add(mapping.get(s));
Now not only did I save the time it took me to type full variable names and curly braces (freeing me to spend 5 more seconds to think deep algorithmic thoughts), but I can also enter my code in obfuscation contests and potent...
Generate a random double in a range
...
This question was asked before Java 7 release but now, there is another possible way using Java 7 (and above) API:
double random = ThreadLocalRandom.current().nextDouble(min, max);
nextDouble will return a pseudorandom double value between the minimum (inclusive) and the ...
Find the closest ancestor element that has a specific class
...
Update: Now supported in most major browsers
document.querySelector("p").closest(".near.ancestor")
Note that this can match selectors, not just classes
https://developer.mozilla.org/en-US/docs/Web/API/Element.closest
For legac...
How to execute a Python script from the Django shell?
...nd
class Command(BaseCommand):
def handle(self, **options):
# now do the things that you want with your models here
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What's the difference between “STL” and “C++ Standard Library”?
...long before C++ was standardised. C++ existed through the 80s, but what we now call "C++" is the language standardised in ISO/IEC 14882:2014 (and earlier versions, such as ISO/IEC 14882:2011).
The STL was already widely used as a library for C++, giving programmers access to containers, iterators a...
In a storyboard, how do I make a custom cell for use with multiple controllers?
... don't care about why these other attempts didn't work, feel free to leave now. I've got no magical workarounds for you, other than suggesting that you file a bug.)
A storyboard is, in essence, not much more than a collection of .xib files. When you load up a table view controller that has some pro...
Comma in C/C++ macro
...tructs behind the macro become dependent types, and the typename prefix is now required on the type. You can add it, but type deduction has been broken, so you now have to manually list the type arguments to call the function. I ended up using temple's method of defining a macro for the comma. It mi...
How to prevent ifelse() from turning Date objects into numeric objects
...<- "Date"
str(dates)
At first this felt a little "hackish" to me. But now I just think of it as a small price to pay for the performance returns that I get from ifelse(). Plus it's still a lot more concise than a loop.
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What is the Python equivalent of Matlab's tic and toc functions?
...TicToc, marks the beginning of a time interval
toc(False)
That's it! Now we are ready to fully use tic() and toc() just as in Matlab. For example
tic()
time.sleep(5)
toc() # returns "Elapsed time: 5.00 seconds."
Actually, this is more versatile than the built-in Matlab functions. Here, ...
Proper way to declare custom exceptions in modern Python?
...it needs
super(ValidationError, self).__init__(message)
# Now for your custom code...
self.errors = errors
That way you could pass dict of error messages to the second param, and get to it later with e.errors
Python 3 Update: In Python 3+, you can use this slightly more...