Tutorial by Examples: l

Once the instance of the BackgroundWorker has been declared, it must be given properties and event handlers for the tasks it performs. /* This is the backgroundworker's "DoWork" event handler. This method is what will contain all the work you wish to have your progra...

The following example demonstrates the use of a BackgroundWorker to update a WinForms ProgressBar. The backgroundWorker will update the value of the progress bar without blocking the UI thread, thus showing a reactive UI while work is done in the background. namespace BgWorkerExample { public...

Python supports a translate method on the str type which allows you to specify the translation table (used for replacements) as well as any characters which should be deleted in the process. str.translate(table[, deletechars]) ParameterDescriptiontableIt is a lookup table that defines the mappin...

Elements come with angle brackets are the most prominent building block of XML. Elements can either be empty, in which case they are made of an empty tag (notice the ending slash): <an-empty-element/> Or they can have content, in which case they have an opening tag (no slash) and a closin...

The foreach package brings the power of parallel processing to R. But before you want to use multi core CPUs you have to assign a multi core cluster. The doSNOW package is one possibility. A simple use of the foreach loop is to calculate the sum of the square root and the square of all numbers from...

A good use of extension method is to make the language more functional Sub Main() Dim strings = { "One", "Two", "Three" } strings.Join(Environment.NewLine).Print() End Sub <Extension> Public Function Join(strings As IEnumerable(Of String), separa...

These two documents are semantically equivalement, as namespaces matter, not prefixes. <?xml version="1.0"?> <myns:foo xmlns:myns="http://www.example.com/my-namespace"> </myns:foo> <?xml version="1.0"?> <ns:foo xmlns:ns="http://www...

Installing linq-to-sql: Right-click the App_Code folder and then click Add New Item. The Add New Item dialog box is displayed. Under Visual Studio installed templates, select the LINQ to SQL Classes template and rename the file Tasks.dbml. Click Add. OR: Under VS2102, in your solution explorer, r...

import pandas as pd Create a DataFrame from a dictionary, containing two columns: numbers and colors. Each key represent a column name and the value is a series of data, the content of the column: df = pd.DataFrame({'numbers': [1, 2, 3], 'colors': ['red', 'white', 'blue']}) Show contents of d...

Create a DataFrame of random numbers: import numpy as np import pandas as pd # Set the seed for a reproducible sample np.random.seed(0) df = pd.DataFrame(np.random.randn(5, 3), columns=list('ABC')) print(df) # Output: # A B C # 0 1.764052 0.400157 0.9787...

Single line comments are preceded by --, and go until the end of the line: SELECT * FROM Employees -- this is a comment WHERE FName = 'John'

Multi-line code comments are wrapped in /* ... */: /* This query returns all employees */ SELECT * FROM Employees It is also possible to insert such a comment into the middle of a line: SELECT /* all columns: */ * FROM Employees

Imports System.Reflection Public Class PropertyExample Public Function GetMyProperties() As PropertyInfo() Dim objProperties As PropertyInfo() objProperties = Me.GetType.GetProperties(BindingFlags.Public Or BindingFlags.Instance) Return objProperties End Fun...

As Handlers are used to send Messages and Runnables to a Thread's message queue it's easy to implement event based communication between multiple Threads. Every Thread that has a Looper is able to receive and process messages. A HandlerThread is a Thread that implements such a Looper, for example th...

Use Ctrl + C, Ctrl + C to exit iex(1)> BREAK: (a)bort (c)ontinue (p)roc info (i)nfo (l)oaded (v)ersion (k)ill (D)b-tables (d)istribution Use Ctrl+ \ to immediately exit

Syntax: REPLACE( String to search , String to search for and replace , String to place into the original string ) Example: SELECT REPLACE( 'Peter Steve Tom', 'Steve', 'Billy' ) --Return Values: Peter Billy Tom

p { margin:1px; /* 1px margin in all directions */ /*equals to:*/ margin:1px 1px; /*equals to:*/ margin:1px 1px 1px; /*equals to:*/ margin:1px 1px 1px 1px; } Another exapmle: p{ margin:10px 15px; /...

g$ The above matches one letter (the letter g) at the end of a string in most regex engines (not in Oniguruma, where the $ anchor matches the end of a line by default, and the m (MULTILINE) modifier is used to make a . match any characters including line break characters, as a DOTALL modifier in ...

my $filename = '/path/to/file'; open my $fh, '<', $filename or die "Failed to open file: $filename"; # You can then either read the file one line at a time... while(chomp(my $line = <$fh>)) { print $line . "\n"; } # ...or read whole file into an arra...

You can use subqueries to define a temporary table and use it in the FROM clause of an "outer" query. SELECT * FROM (SELECT city, temp_hi - temp_lo AS temp_var FROM weather) AS w WHERE temp_var > 20; The above finds cities from the weather table whose daily temperature variation i...