Searching in nested sequences like a list of tuple requires an approach like searching the keys for values in dict but needs customized functions.
The index of the outermost sequence if the value was found in the sequence:
def outer_index(nested_sequence, value):
return next(index for index, ...
Abbreviated from https://blogs.dropbox.com/developers/2013/07/using-oauth-2-0-with-the-core-api/:
Step 1: Begin authorization
Send the user to this web page, with your values filled in:
https://www.dropbox.com/oauth2/authorize?client_id=<app key>&response_type=code&redirect_uri=<...
You can use a custom toJSON method and reviver function to transmit instances of your own class in JSON. If an object has a toJSON method, its result will be serialized instead of the object itself.
6
function Car(color, speed) {
this.color = color;
this.speed = speed;
}
Car.prototype.to...
Classes are reference types, meaning that multiple variables can refer to the same instance.
class Dog {
var name = ""
}
let firstDog = Dog()
firstDog.name = "Fido"
let otherDog = firstDog // otherDog points to the same Dog instance
otherDog.name = "Rover" // modifying otherDog also...
In MATLAB, the most basic data type is the numeric array. It can be a scalar, a 1-D vector, a 2-D matrix, or an N-D multidimensional array.
% a 1-by-1 scalar value
x = 1;
To create a row vector, enter the elements inside brackets, separated by spaces or commas:
% a 1-by-4 row vector
v = [1, 2...
When working with dictionaries, it's often necessary to access all the keys and values in the dictionary, either in a for loop, a list comprehension, or just as a plain list.
Given a dictionary like:
mydict = {
'a': '1',
'b': '2'
}
You can get a list of keys using the keys() method:
...
Print element at index 0
echo "${array[0]}"
4.3
Print last element using substring expansion syntax
echo "${arr[@]: -1 }"
4.3
Print last element using subscript syntax
echo "${array[-1]}"
Print all elements, each quoted separately
echo "${array[@...
astring = 'thisisashorttext'
astring.count('t')
# Out: 4
This works even for substrings longer than one character:
astring.count('th')
# Out: 1
astring.count('is')
# Out: 2
astring.count('text')
# Out: 1
which would not be possible with collections.Counter which only counts single char...
Java SE 7
As the try-catch-final statement example illustrates, resource cleanup using a finally clause requires a significant amount of "boiler-plate" code to implement the edge-cases correctly. Java 7 provides a much simpler way to deal with this problem in the form of the try-with-res...
There are several ways to extract characters from a std::string and each is subtly different.
std::string str("Hello world!");
operator[](n)
Returns a reference to the character at index n.
std::string::operator[] is not bounds-checked and does not throw an exception. The caller is...
A C++ namespace is a collection of C++ entities (functions, classes, variables), whose names are prefixed by the name of the namespace. When writing code within a namespace, named entities belonging to that namespace need not be prefixed with the namespace name, but entities outside of it must use t...
Creating a namespace is really easy:
//Creates namespace foo
namespace Foo
{
//Declares function bar in namespace foo
void bar() {}
}
To call bar, you have to specify the namespace first, followed by the scope resolution operator :::
Foo::bar();
It is allowed to create one names...
A useful feature of namespaces is that you can expand them (add members to it).
namespace Foo
{
void bar() {}
}
//some other stuff
namespace Foo
{
void bar2() {}
}
There are three keywords that act as access specifiers. These limit the access to class members following the specifier, until another specifier changes the access level again:
KeywordDescriptionpublicEveryone has accessprotectedOnly the class itself, derived classes and friends have accessprivate...
There are two primary ways of accessing elements in a std::vector
index-based access
iterators
Index-based access:
This can be done either with the subscript operator [], or the member function at().
Both return a reference to the element at the respective position in the std::vector (unles...
import multiprocessing
def fib(n):
"""computing the Fibonacci in an inefficient way
was chosen to slow down the CPU."""
if n <= 2:
return 1
else:
return fib(n-1)+fib(n-2)
p = multiprocessing.Pool()
print(p.map(fib,[38,37,3...
