Tutorial by Examples: od

encode/decode to hex no longer available

Python 2.x2.7 "1deadbeef3".decode('hex') # Out: '\x1d\xea\xdb\xee\xf3' '\x1d\xea\xdb\xee\xf3'.encode('hex') # Out: 1deadbeef3 Python 3.x3.0 "1deadbeef3".decode('hex') # Traceback (most recent call last): # File "<stdin>", line 1, in <module> ...

Python Language • Incompatibilities moving from Python 2 to Python 3

Modifying a string literal

C++11 char *str = "hello world"; str[0] = 'H'; "hello world" is a string literal, so modifying it gives undefined behaviour. The initialisation of str in the above example was formally deprecated (scheduled for removal from a future version of the standard) in C++03. A num...

C++ • Undefined Behavior

Spreadsheet to dict of DataFrames

with pd.ExcelFile('path_to_file.xls) as xl: d = {sheet_name: xl.parse(sheet_name) for sheet_name in xl.sheet_names}

pandas • Pandas IO tools (reading and saving data sets)

Extension methods as strongly typed wrappers

Extension methods can be used for writing strongly typed wrappers for dictionary-like objects. For example a cache, HttpContext.Items at cetera... public static class CacheExtensions { public static void SetUserInfo(this Cache cache, UserInfo data) => cache["UserInfo"] ...

C# Language • Extension Methods

Inline with



            
            
If a sentence contains computer code (for example, the name of an HTML element), use the code element to mark it up:
&lt;p&gt;The &lt;code&gt;a&lt;/code&gt; element creates a hyperlink.&lt;/p&gt;


            

            
            
                
                    
                        HTML
                        •
                        Marking up computer code





    

        

            
            
                
                    Block with  and 
                

            


            
            
If the formatting (white space, new lines, indentation) of the code matters, use the pre element in combination with the code element:
&lt;pre&gt;
    &lt;code&gt;
    x = 42
    if x == 42:
        print &quot;x is …          … 42&quot;
    &lt;/code&gt;
&lt;/pre&gt;

You still have to esc...            

            
            
                
                    
                        HTML
                        •
                        Marking up computer code
                        
                    
                    
                
            
        

    





    

        

            
            
                
                    Basic decoding / unmarshalling of nested elements with data
                
            

            
            
XML elements often nest, have data in attributes and/or as character data. The way to capture this data is by using ,attr and ,chardata respectively for those cases.
var doc = `
&lt;parent&gt;
  &lt;child1 attr1=&quot;attribute one&quot;/&gt;
  &lt;child2&gt;and some cdata&lt;/child2&gt;
&lt;/p...            

            
            
                
                    
                        Go
                        •
                        XML
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Pointer v. Value Methods
                
            

            
            
Pointer Methods
Pointer methods can be called even if the variable is itself not a pointer.
According to the Go Spec,

. . . a reference to a non-interface method with a pointer receiver using an addressable value will automatically take the address of that value: t.Mp is equivalent to (&amp;t)....            

            
            
                
                    
                        Go
                        •
                        Pointers
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Export a Remote Mongo DB, Import Into a Local Meteor Mongo DB
                
            

            
            
Helpful when you want to grab a copy of a production database to play around with locally.

mongodump --host some-mongo-host.com:1234 -d DATABASE_NAME -u DATABASE_USER -p DATABASE_PASSWORD This will create a local dump directory; within that directory you'll see a directory with your DATABASE_NAME...            

            
            
                
                    
                        meteor
                        •
                        MongoDB
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Get the Mongo URL of Your Local Meteor Mongo DB
                
            

            
            
While your Meteor app is running locally:
meteor mongo --url


            

            
            
                
                    
                        meteor
                        •
                        MongoDB
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Connect Your Local Meteor App to an Alternative Mongo DB
                
            

            
            
Set the MONGO_URL environment variable before starting your local Meteor app.
Linux/MacOS Example:
MONGO_URL=&quot;mongodb://some-mongo-host.com:1234/mydatabase&quot; meteor

or
export MONGO_URL=&quot;mongodb://some-mongo-host.com:1234/mydatabase&quot; 
meteor

Windows Example
Note: don't u...            

            
            
                
                    
                        meteor
                        •
                        MongoDB
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Get current store code
                
            

            
            
Mage::app()-&gt;getStore()-&gt;getCode();

This returns store code, e.g. 'en' for a storefront that is setup for English and called 'en', and not the numerical id.

            

            
            
                
                    
                        magento
                        •
                        Get store name and other details from system configuration
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Get the current store model
                
            

            
            
Mage::app()-&gt;getStore();

Returns an instance of Mage_Core_Model_Store

            

            
            
                
                    
                        magento
                        •
                        Get store name and other details from system configuration
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Counting Method References On Every Build (Dexcount Gradle Plugin)
                
            

            
            
The dexcount plugin counts methods and class resource count after a successful build.
Add the plugin in the app/build.gradle:
apply plugin: 'com.android.application'

buildscript {
    repositories {
        mavenCentral() // or jcenter()
    }

    dependencies {
        classpath 'com.ge...            

            
            
                
                    
                        Android
                        •
                        Multidex and the Dex Method Limit
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Running normal commands from insert mode
                
            

            
            
While in insert mode, press &lt;C-o&gt; to temporarily leave insert mode and execute a one-off normal command.
Example
&lt;C-o&gt;2w jumps to the second word to the left and returns to insert mode.
Note: Repeating with . will only repeat the actions from returning to insert mode
This allows for ...            

            
            
                
                    
                        vim
                        •
                        Inserting text
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Altering the HTTP method (GET, POST, PUT, etc)
                
            

            
            
The URLRequestMethod class contains constants for the various request types you can make. These constants are to be allocated to URLRequest's method property:
var request:URLRequest = new URLRequest('http://someservice.com');
request.method = URLRequestMethod.POST;


Note that only GET and POST...            

            
            
                
                    
                        ActionScript 3
                        •
                        Sending and Receiving Data From Servers
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Whether a number is an odd value
                
            

            
            
function isOdd(n:Number):Boolean {
    return ((n &amp; 1) == 1);
}

Examples:
isOdd(1); // true
isOdd(2); // false

isOdd(1.1); // true
isOdd(1.2); // true
isOdd(2.1); // false
isOdd(2.2); // false


            

            
            
                
                    
                        ActionScript 3
                        •
                        Working with numerical values
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    IO defines your program's `main` action
                
            

            
            
To make a Haskell program executable you must provide a file with a main function of type IO ()
main :: IO ()
main = putStrLn &quot;Hello world!&quot;

When Haskell is compiled it examines the IO data here and turns it into a executable. When we run this program it will print Hello world!.
If y...            

            
            
                
                    
                        Haskell Language
                        •
                        IO
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Introduction
                
            

            
            
Laravel allows access to a variety of classes called Services. Some services are available out of the box, but you can create them by yourself.
A service can be used in multiple files of the application, like controllers. Let's imagine a Service OurService implementing a getNumber() method returnin...            

            
            
                
                    
                        Laravel
                        •
                        Services
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Introduction
                
            

            
            
The Service Container is the main Application object. It can be used as a Dependency Injection Container, and a Registry for the application by defining bindings in the Service Providers
Service Providers are classes where we define the way our service classes will be created through the applicatio...            

            
            
                
                    
                        Laravel
                        •
                        Services