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Python Pandas: Get index of rows which column matches certain value
... frame (whose data may be gibabytes). What about dftest? Doesn't this also allocate a very large intermediate object where the returned index may be very small, or even empty. Are these magically optimized away using lazy views. If not then surely there must be an efficient way.
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How would one write object-oriented code in C? [closed]
What are some ways to write object-oriented code in C? Especially with regard to polymorphism.
32 Answers
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What is lexical scope?
...
I understand them through examples. :)
First, lexical scope (also called static scope), in C-like syntax:
void fun()
{
int x = 5;
void fun2()
{
printf("%d", x);
}
}
Every inner level can access its outer levels.
There is another way, called dynamic scope used by ...
Looping through localStorage in HTML5 and JavaScript
...
In addition to all the other answers, you can use $.each function from the jQuery library:
$.each(localStorage, function(key, value){
// key magic
// value magic
});
Eventually, get the object with:
JSON.parse(localStorage.getI...
How do I set a cookie on HttpClient's HttpRequestMessage
...instantiated once and re-used throughout the life of an application. Especially in server applications, creating a new HttpClient instance for every request will exhaust the number of sockets available under heavy loads..." From here: asp.net/web-api/overview/advanced/…
– Ser...
How to define “type disjunction” (union types)?
...str")
case _: Int => println("int")
}
}
And that's it. You can call foo(5) or foo("abc"), and it will work, but try foo(true) and it will fail. This could be side-stepped by the client code by creating a StringOrInt[Boolean], unless, as noted by Randall below, you make StringOrInt a seale...
Passing variable arguments to another function that accepts a variable argument list
...gs)
{
...whatever you planned to have exampleB do...
...except it calls neither va_start nor va_end...
}
share
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Check if two unordered lists are equal [duplicate]
...has a built-in datatype for an unordered collection of (hashable) things, called a set. If you convert both lists to sets, the comparison will be unordered.
set(x) == set(y)
Documentation on set
EDIT: @mdwhatcott points out that you want to check for duplicates. set ignores these, so you need ...
Multi-Line Comments in Ruby?
.....is kinda ugly and creates
a String instance, but I know one guy
with a Smalltalk background, who
does this."
puts "Hello world!"
##
# most
# people
# do
# this
__END__
But all forgot there is another option.
Only at the end of a file, of course.
This is how it looks (via screenshot) - othe...
Equivalent C++ to Python generator pattern
...to signal termination
In your trivial example, it's easy enough. Conceptually:
struct State { unsigned i, j; };
State make();
void next(State&);
bool isDone(State const&);
Of course, we wrap this as a proper class:
class PairSequence:
// (implicit aliases)
public std::iterat...