Tutorial by Examples: s

hashlib.new requires the name of an algorithm when you call it to produce a generator. To find out what algorithms are available in the current Python interpreter, use hashlib.algorithms_available: import hashlib hashlib.algorithms_available # ==> {'sha256', 'DSA-SHA', 'SHA512', 'SHA224', 'dsa...

The PBKDF2 algorithm exposed by hashlib module can be used to perform secure password hashing. While this algorithm cannot prevent brute-force attacks in order to recover the original password from the stored hash, it makes such attacks very expensive. import hashlib import os salt = os.urandom...

This method gets the user agent and parses it to find the browser. The browser name and version are extracted from the user agent through a regex. Based on these two, the <browser name> <version> is returned. The four conditional blocks following the user agent matching code are meant t...

Let's add a custom operator to multiply a CGSize func *(lhs: CGFloat, rhs: CGSize) -> CGSize{ let height = lhs*rhs.height let width = lhs*rhs.width return CGSize(width: width, height: height) } Now this works let sizeA = CGSize(height:100, width:200) let sizeB = 1.1 * si...

When we have two separate array and we want to make key value pair from that two array, we can use array's reduce function like below: var columns = ["Date", "Number", "Size", "Location", "Age"]; var rows = ["2001", "5", "B...

A programming best practice is to free any memory that has been allocated directly by your own code, or implicitly by calling an internal or external function, such as a library API like strdup(). Failing to free memory can introduce a memory leak, which could accumulate into a substantial amount of...

Detailed instructions on getting asp.net-mvc-4 set up or installed.

To get the size of a communicator (e.g. MPI_COMM_WORLD) and the local process' rank inside it: int rank, size; int res; MPI_Comm communicator = MPI_COMM_WORLD; res = MPI_Comm_rank (communicator, &rank); if (res != MPI_SUCCESS) { fprintf (stderr, "MPI_Comm_rank failed\n"); ...

The following code broadcasts the contents in buffer among all the processes belonging to the MPI_COMM_WORLD communicator (i.e. all the processes running in parallel) using the MPI_Bcast operation. int rank; int res; res = MPI_Comm_rank (MPI_COMM_WORLD, &rank); if (res != MPI_SUCCESS) { ...

Floating point types (float, double and long double) cannot precisely represent some numbers because they have finite precision and represent the values in a binary format. Just like we have repeating decimals in base 10 for fractions such as 1/3, there are fractions that cannot be represented fini...

PREPARE prepares a statement for execution EXECUTE executes a prepared statement DEALLOCATE PREPARE releases a prepared statement SET @s = 'SELECT SQRT(POW(?,2) + POW(?,2)) AS hypotenuse'; PREPARE stmt2 FROM @s; SET @a = 6; SET @b = 8; EXECUTE stmt2 USING @a, @b; Result: +------------+ |...

WebGL is a browser technology so there isn't much to set up other than to have a browser. You can get started with WebGL on JSFiddle or Codepen or JSBIn or any number of other sites that let you edit HTML, CSS, and JavaScript online though there will be a few limitations (see below). You can also ho...

The pickle module implements an algorithm for turning an arbitrary Python object into a series of bytes. This process is also called serializing the object. The byte stream representing the object can then be transmitted or stored, and later reconstructed to create a new object with the same charact...

Using the calendar module import calendar from datetime import date def monthdelta(date, delta): m, y = (date.month+delta) % 12, date.year + ((date.month)+delta-1) // 12 if not m: m = 12 d = min(date.day, calendar.monthrange(y, m)[1]) return date.replace(day=d,month=m, year=...

To install v6.x update the packages curl -sL https://deb.nodesource.com/setup_6.x | sudo -E bash - Using the apt package manager sudo apt-get install -y nodejs

Download driver via nuget. Using this command in the package manager console Install-Package mongocsharpdriver

#include <stdio.h> #include <stdlib.h> int main (void) { int * pdata; size_t n; printf ("Enter the size of the array: "); fflush(stdout); /* Make sure the prompt gets printed to buffered stdout. */ if (1 != scanf("%zu", &n)) /* If zu is n...

Vectors in R can have different types (e.g. integer, logical, character). The most general way of defining a vector is by using the function vector(). vector('integer',2) # creates a vector of integers of size 2. vector('character',2) # creates a vector of characters of size 2. vector('logical',2...

Detailed instructions on getting pymongo set up or installed. Installing with Pip To install pymongo for the first time: pip install pymongo Installing a specific version of pymongo: Where X.X.X is the version to be installed pip install pymongo==X.X.X Upgrading existing pymon...

Stanford CoreNLP is a popular Natural Language Processing toolkit supporting many core NLP tasks. To download and install the program, either download a release package and include the necessary *.jar files in your classpath, or add the dependency off of Maven central. See the download page for mor...