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increment date by one month
...nd added more comments to help me understand it all. In case that helps anyone, I have posted it further down (tried to add it here but it was too long).
– Greg
Nov 13 '16 at 20:11
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What's this =! operator? [duplicate]
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That's two operators, = and !, not one. It might be an obfuscated way of writing
a = !b;
if (a) {
// whatever
}
setting a to the logical inverse of b, and testing whether the result is true (or, equivalently, whether b was false).
Or it might be a mist...
Python extending with - using super() Python 3 vs Python 2
...r: global name '__class__' is not defined, and super(self.__class__) is erroneous as well. You must provide an instance as a second argument, which would suggest you need to do super(self.__class__, self), but that is wrong. If Class2 inherits from Class1 and Class1 calls super(self.__class__, self)...
What's the safest way to iterate through the keys of a Perl hash?
...h may in some way have unintended side effects. So, is that true, and is one of the two following methods best, or is there a better way?
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How to sort a dataframe by multiple column(s)
... z = c(1, 1, 1, 2))
library(taRifx)
sort(dd, f= ~ -z + b )
If you are one of the original authors of this function, please contact me. Discussion as to public domaininess is here: http://chat.stackoverflow.com/transcript/message/1094290#1094290
You can also use the arrange() function from p...
Is HttpClient safe to use concurrently?
In all the examples I can find of usages of HttpClient , it is used for one off calls. But what if I have a persistent client situation, where several requests can be made concurrently? Basically, is it safe to call client.PostAsync on 2 threads at once against the same instance of HttpClient .
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Signtool error: No certificates were found that met all given criteria with a Windows Store App?
...install the missing certificate. Alternatively you can always create a new one and use that!
– JDandChips
Mar 16 '16 at 10:32
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Make .git directory web inaccessible
...llow,deny
Deny from all
But note, that it would be lost if you ever re-cloned the repository
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PostgreSQL - fetch the row which has the Max value for a column
... vary in production based on actual machine load/data access spread. When one query appears slightly faster (<20%) than the other but has a much higher cost, it will generally be wiser to choose the one with higher execution time but lower cost.
When you expect that there will be no competition...
Convert two lists into a dictionary
...rnandoWittmann. {thing} is syntactic sugar to construct a set() containing one element. {*iterable} is syntactic sugar to construct a set containing several elements. {k:v} or {**mapping} will construct a dict, but that's syntactically quite distinct.
– Dan Lenski
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