Tutorial by Examples: in

Python 2.x2.7 In Python 2 filter, map and zip built-in functions return a sequence. map and zip always return a list while with filter the return type depends on the type of given parameter: >>> s = filter(lambda x: x.isalpha(), 'a1b2c3') >>> s 'abc' >>> s = map(lambd...

When we want to create an orderable class, normally we need to define the methods __eq()__, __lt__(), __le__(), __gt__() and __ge__(). The total_ordering decorator, applied to a class, permits the definition of __eq__() and only one between __lt__(), __le__(), __gt__() and __ge__(), and still allow...

public class Foo { private const int TASK_ITERATION_DELAY_MS = 1000; private CancellationTokenSource _cts; public Foo() { this._cts = new CancellationTokenSource(); } public void StartExecution() { Task.Factory.StartNew(this.OwnCodeCancelable...

public class Foo { private CancellationTokenSource _cts; public Foo() { this._cts = new CancellationTokenSource(); } public void StartExecution() { Task.Factory.StartNew(this.OwnCodeCancelableTask, this._cts.Token); } public void Cance...

/// <summary> /// Registers a background task in the system waiting to trigger /// </summary> /// <param name="taskName">Name of the task. Has to be unique</param> /// <param name="taskEntryPoint">Entry point (Namespace) of the class (has to impl...

var trigger = new ApplicationTrigger(); TaskHandlerMentionedInThisTutorial.RegisterTask(TaskName, entryPoint, trigger, null, true); await trigger.RequestAsync();

/// <summary> /// Unregister a single background task with given name /// </summary> /// <param name="taskName">task name</param> /// <param name="cancelTask">true if task should be cancelled, false if allowed to finish</param> public void...

In order to login to a user's account on machine with SSH you can use the command ssh username@ip_address. It will ask for a password. If you type the correct password, you will be connected to the shell of that user on that machine. Otherwise it will prompt for the password again. For example roo...

Lubridate provides ymd() series of functions for parsing character strings into dates. The letters y, m, and d correspond to the year, month, and day elements of a date-time. mdy("07-21-2016") # Returns Date ## [1] "2016-07-21" mdy("07-21-2016", t...

date <- now() date ## "2016-07-22 03:42:35 IST" year(date) ## 2016 minute(date) ## 42 wday(date, label = T, abbr = T) # [1] Fri # Levels: Sun < Mon < Tues < Wed < Thurs < Fri < Sat day(date) <- 31 ## "2016-07-31 03:42:35 IST" # If an ...

An instant is a specific moment in time. Any date-time object that refers to a moment of time is recognized as an instant. To test if an object is an instant, use is.instant. library(lubridate) today_start <- dmy_hms("22.07.2016 12:00:00", tz = "IST") # default tz="UT...

Intervals are simplest way of recording timespans in lubridate. An interval is a span of time that occurs between two specific instants. # create interval by substracting two instants today_start <- ymd_hms("2016-07-22 12-00-00", tz="IST") today_start ## [1] "2016-07-...

now_dt <- ymd_hms(now(), tz="IST") now_dt ## [1] "2016-07-22 13:53:09 IST" round_date() takes a date-time object and rounds it to the nearest integer value of the specified time unit. round_date(now_dt, "minute") ## [1] "2016-07-22 13:53:00 IST" r...

CSS: div{ width:200px; height:200px; background:teal; clip-path: polygon(0 0, 0 100%, 100% 50%); /* refer remarks before usage */ } HTML: <div></div> In the above example, a polygonal clipping path is used to clip the square (200 x 200) element into a triangle shape....

CSS: div{ width: 200px; height: 200px; background: teal; clip-path: circle(30% at 50% 50%); /* refer remarks before usage */ } HTML <div></div> This example shows how to clip a div to a circle. The element is clipped into a circle whose radius is 30% based on the dim...

Using Homebrew Prerequisites: Make sure you're on OS X 10.9 (Mavericks) or above, and have Homebrew installed. Run the following in your terminal: brew update && brew install rethinkdb Compile from source Building RethinkDB from source requires OS X 10.9 (Mavericks) or greater. Xcode...

GROUP BY is used in combination with aggregation functions. Consider the following table: orderIduserIdstoreNameorderValueorderDate143Store A2520-03-2016257Store B5022-03-2016343Store A3025-03-2016482Store C1026-03-2016521Store A4529-03-2016 The query below uses GROUP BY to perform aggregated calc...

Protocol Oriented Programming is a useful tool in order to easily write better unit tests for our code. Let's say we want to test a UIViewController that relies on a ViewModel class. The needed steps on the production code are: Define a protocol that exposes the public interface of the class Vi...

You can use fprintf on a file just like you might on a console with printf. For example to keep track of game wins, losses and ties you might write /* saves wins, losses and, ties */ void savewlt(FILE *fout, int wins, int losses, int ties) { fprintf(fout, "Wins: %d\nTies: %d\nLosses: %d...

The POSIX C library defines the getline() function. This function allocates a buffer to hold the line contents and returns the new line, the number of characters in the line, and the size of the buffer. Example program that gets each line from example.txt: #include <stdlib.h> #include <s...