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Is there a difference between “==” and “is”?
...> b == a
True
# Make a new copy of list `a` via the slice operator,
# and assign it to variable `b`
>>> b = a[:]
>>> b is a
False
>>> b == a
True
In your case, the second test only works because Python caches small integer objects, which is an implementation detail...
Scala: What is the difference between Traversable and Iterable traits in Scala collections?
I have looked at this question but still don't understand the difference between Iterable and Traversable traits. Can someone explain ?
...
JRE 1.7 - java version - returns: java/lang/NoClassDefFoundError: java/lang/Object
...nstallation.
Possibility 1
NOTE: This scenario only applies to Java 8 and prior. Beginning with Java 9, the JRE is structured differently. rt.jar and friends no longer exist, and Pack200 is no longer used.
The Java standard library is contained in various JARs, such as rt.jar, deploy.jar, jss...
Node.js on multi-core machines
... must miss something - isn't Node.js tuned only to run on a single process and thread?
15 Answers
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Django REST framework: non-model serializer
I am beginner in Django REST framework and need your advice. I am developing a web service. The service has to provide REST interface to other services. The REST interface, which I need to implement, is not working with my models directly (I mean the get, put, post, delete operations). Instead, it p...
How to express infinity in Ruby?
...own constant using the following*:
I've checked that in Ruby 1.8.6, 1.8.7, and 1.9.2 you have Float.infinite?.
PositiveInfinity = +1.0/0.0
=> Infinity
NegativeInfinity = -1.0/0.0
=> -Infinity
CompleteInfinity = NegativeInfinity..PositiveInfinity
=> -Infinity..Infinity
*I've verified ...
What is the difference between List (of T) and Collection(of T)?
I've seen them used in a lot of the same ways, and I am worried I'm about to go down a path in design that is irreversible if I don't understand this better. Also, I am using .NET.
...
Does ruby have real multithreading?
...e confusing two very different things here: the
Ruby Programming Language and the specific threading model of one
specific implementation of the Ruby Programming Language. There
are currently around 11 different implementations of the Ruby
Programming Language, with very different and unique thr...
Why do x86-64 systems have only a 48 bit virtual address space?
...st only use the lower 48 bits. The alternative was wasting transistors on handling a bigger address space which wasn't going to be needed for many years.
So once we get near the 48-bit limit, it's just a matter of releasing CPUs that handle the full address space, but it won't require any changes t...
How does type Dynamic work and how to use it?
...se one of these methods it is enough to write a class that extends Dynamic and to implement the methods there:
class DynImpl extends Dynamic {
// method implementations here
}
Furthermore one need to add a
import scala.language.dynamics
or set the compiler option -language:dynamics because t...