Tutorial by Examples: an

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...

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...

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

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-...

Unlike durations, periods can be used to accurately model clock times without knowing when events such as leap seconds, leap days, and DST changes occur. start_2012 <- ymd_hms("2012-01-01 12:00:00") ## [1] "2012-01-01 12:00:00 UTC" # period() considers leap year calculati...

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...

When something fails in your transaction code and you want to undo it, you can rollback your transaction: BEGIN TRY BEGIN TRANSACTION INSERT INTO Users(ID, Name, Age) VALUES(1, 'Bob', 24) DELETE FROM Users WHERE Name = 'Todd' COMMIT TRANSACTION END TRY...

Creating a hub A quick configuration for a hub and node setup in selenium grid. For more information see: Grid 2 docs Requirements To set up a grid hub you need the flowing: Selenium-server-standalone-.jar Creating the hub To Create a Hub you need to run the selenium server. Download Se...

The Android specific implementation is a bit more complex because it forces you to inherit from a native Java.Lang.Object and forces you to implement the IOnInitListener interface. Android requires you to provide a valid Android context for a lot of the SDK methods it exposes. Xamarin.Forms exposes ...

' Sometimes we don't need to evaluate all the conditions in an if statement's boolean check. ' Let's suppose we have a list of strings: Dim MyCollection as List(Of String) = New List(of String)() ' We want to evaluate the first value inside our list: If MyCollection.Count > 0 And MyCo...

It is now a best-practice to use Vector instead of List because the implementations have better performance Performance characteristics can be found here. Vector can be used wherever List is used. List creation List[Int]() // Declares an empty list of type Int List.empty[Int] // U...

//Swift imageView.tintColor = UIColor.redColor() imageView.image = imageView.image?.imageWithRenderingMode(.AlwaysTemplate) //Swift 3 imageView.tintColor = UIColor.red imageView.image = imageView.image?.withRenderingMode(.alwaysTemplate) //Objective-C imageView.tintColor = [UIColor redCol...

The Scala compiler prefixes every argument in the parameter list by default with val. This means that, by default, case classes are immutable. Each parameter is given an accessor method, but there are no mutator methods. For example: case class Foo(i: Int) val fooInstance = Foo(1) val j = fooIn...

Apply will be used when when table valued function in the right expression. create a Department table to hold information about departments. Then create an Employee table which hold information about the employees. Please note, each employee belongs to a department, hence the Employee table has ref...

In normal mode, we can increment the nearest number on the line at or after the cursor with <C-a> and decrement it with <C-x>. In the following examples, the cursor position is indicated by ^. Incrementing and decrementing numbers for i in range(11): ^ <C-x> decrements ...

The core idea behind the Feature Branch Workflow is that all feature development should take place in a dedicated branch instead of the master branch. This encapsulation makes it easy for multiple developers to work on a particular feature without disturbing the main codebase. It also means the mast...