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applicationWillEnterForeground vs. applicationDidBecomeActive, applicationWillResignActive vs. appli
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Revise some descriptions and links, 2019 for now.
– tomjpsun
Sep 20 '19 at 2:56
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Understanding exactly when a data.table is a reference to (vs a copy of) another data.table
...avoid for large data, and why := and set() were introduced to data.table.
Now, with our copied newDT we can modify it by reference :
newDT
# a b
# [1,] 1 11
# [2,] 2 200
newDT[2, b := 400]
# a b # See FAQ 2.21 for why this prints newDT
# [1,] 1 11
# [2,] 2 400
.Internal(in...
What is the easiest way to get the current day of the week in Android?
... (for today):
Sat
Saturday
UPDATE: java8
LocalDate date = LocalDate.now();
DayOfWeek dow = date.getDayOfWeek();
System.out.println("Enum = " + dow);
String dayName = dow.getDisplayName(TextStyle.FULL, Locale.ENGLISH);
System.out.println("FULL = " + dayName);
dayName = dow.getDisplayName(Tex...
Should I compile release builds with debug info as “full” or “pdb-only”?
...the JIT compiler that debug information is available.
Then, what is true now?
Pdb-only – Prior to .NET 2.0, it helped to investigate the crash dumps from released product (customer machines). But it didn't let attaching the debugger. This is not the case from .NET 2.0. It is exactly same as Fu...
Is there a standard for storing normalized phone numbers in a database?
...e number into the following components
C Country code 1-10 digits (right now 4 or less, but that may change)
A Area code (Province/state/region) code 0-10 digits (may actually want a region field and an area field separately, rather than one area code)
E Exchange (prefix, or switch) code 0-10 dig...
How to declare a structure in a header that is to be used by multiple files in c?
...een both usages (separate names and same names), and none has drawbacks I know of, so using the same name makes reading simpler if you don't use C separate "namespaces" for structs and other symbols.
share
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Connecting overloaded signals and slots in Qt 5
...amp;QSpinBox::valueChanged),
slider, &QSlider::setValue);
I know, it's ugly. But there's no way around this. Today's lesson is: do not overload your signals and slots!
Addendum: what's really annoying about the cast is that
one repeats the class name twice
one has to specify the ...
What is the meaning of the term arena in relation to memory?
...e techniques is very specialized and generally only comes in handy if you know exactly what you're doing and why the normal library allocation is not good enough. Note that a good memory allocator will already do lots of magic itself, and you need a decent amount of evidence that that's not good eno...
Catch multiple exceptions in one line (except block)
I know that I can do:
5 Answers
5
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How to get all subsets of a set? (powerset)
... to for i in range(1, 1 << x).
Returning to this years later, I'd now write it like this:
def powerset(s):
x = len(s)
masks = [1 << i for i in range(x)]
for i in range(1 << x):
yield [ss for mask, ss in zip(masks, s) if i & mask]
And then the test code...