Tutorial by Examples: co

Compiling and Running the Example

Assuming a source file of hello_world.v and a top level module of hello_world. The code can be run using various simulators. Most simulators are compiled simulators. They require multiple steps to compile and execute. Generally the First step is to compile the Verilog design. Second step is to ...

verilog • Hello World

Adding a new column

df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]}) print(df) # Output: # A B # 0 1 4 # 1 2 5 # 2 3 6 Directly assign df['C'] = [7, 8, 9] print(df) # Output: # A B C # 0 1 4 7 # 1 2 5 8 # 2 3 6 9 Add a constant column df['C'] = 1 print(df) # Ou...

pandas • Simple manipulation of DataFrames

Compiling with Visual C++ (Command Line)

For programmers coming from GCC or Clang to Visual Studio, or programmers more comfortable with the command line in general, you can use the Visual C++ compiler from the command line as well as the IDE. If you desire to compile your code from the command line in Visual Studio, you first need to set...

C++ • Compiling and Building

ReactJS component written in Typescript

You can use ReactJS's components easily in TypeScript. Just rename the 'jsx' file extension to 'tsx': //helloMessage.tsx: var HelloMessage = React.createClass({ render: function() { return <div>Hello {this.props.name}</div>; } }); ReactDOM.render(<HelloMessage name=&q...

TypeScript • Using Typescript with React (JS & native)

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
                        
                    
                    
                
            
        

    





    

        

            
            
                
                    Column selection of a group
                
            

            
            
When you do a groupby you can select either a single column or a list of columns:
In [11]: df = pd.DataFrame([[1, 1, 2], [1, 2, 3], [2, 3, 4]], columns=[&quot;A&quot;, &quot;B&quot;, &quot;C&quot;])

In [12]: df
Out[12]:
   A  B  C
0  1  1  2
1  1  2  3
2  2  3  4

In [13]: g = df.groupby(...            

            
            
                
                    
                        pandas
                        •
                        Grouping Data
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Converting to boolean
                
            

            
            
Boolean(...) will convert any data type into either true or false.
Boolean(&quot;true&quot;) === true
Boolean(&quot;false&quot;) === true
Boolean(-1) === true
Boolean(1) === true
Boolean(0) === false
Boolean(&quot;&quot;) === false
Boolean(&quot;1&quot;) === true
Boolean(&quot;0&quot;) === t...            

            
            
                
                    
                        JavaScript
                        •
                        Variable coercion/conversion
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Define primary, primary dark, and accent colors
                
            

            
            
You can customize your theme’s color palette.
Using framework APIs
5.0
&lt;style name=&quot;AppTheme&quot; parent=&quot;Theme.Material&quot;&gt;
    &lt;item name=&quot;android:colorPrimary&quot;&gt;@color/primary&lt;/item&gt;
    &lt;item name=&quot;android:colorPrimaryDark&quot;&gt;@color/pri...            

            
            
                
                    
                        Android
                        •
                        Theme, Style, Attribute
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    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
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Declaring Components
                
            

            
            
The primary task of the manifest is to inform the system about the app's components. For example, a manifest file can declare an activity as follows:
&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
&lt;manifest ... &gt;
    &lt;application android:icon=&quot;@drawable/app_icon.pn...            

            
            
                
                    
                        Android
                        •
                        The Manifest File
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Collection Initializers with Parameter Arrays
                
            

            
            
You can mix normal parameters and parameter arrays:
public class LotteryTicket : IEnumerable{
    public int[] LuckyNumbers;
    public string UserName;

    public void Add(string userName, params int[] luckyNumbers){
        UserName = userName;
        Lottery = luckyNumbers;
    }
}

...            

            
            
                
                    
                        C# Language
                        •
                        Collection Initializers
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    How to find the Container's host ip
                
            

            
            
You need to find out the IP address of the container running in the host so you can, for example, connect to the web server running in it.
docker-machine is what is used on MacOSX and Windows.
Firstly, list your machines:
$ docker-machine ls

NAME      ACTIVE   DRIVER       STATE     URL       ...            

            
            
                
                    
                        Docker
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                        Docker network
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    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
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Web.config setup to target 4.5 for correct async behaviour.
                
            

            
            
The web.config system.web.httpRuntime must target 4.5 to ensure the thread will renter the request context before resuming your async method.
&lt;httpRuntime targetFramework=&quot;4.5&quot; /&gt;

Async and await have undefined behavior on ASP.NET prior to 4.5. Async / await will resume on an arb...            

            
            
                
                    
                        C# Language
                        •
                        Async-Await
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Concurrent calls
                
            

            
            
It is possible to await multiple calls concurrently by first invoking the awaitable tasks and then awaiting them.
public async Task RunConcurrentTasks()
{
    var firstTask = DoSomethingAsync();
    var secondTask = DoSomethingElseAsync();

    await firstTask;
    await secondTask;
}

Alt...            

            
            
                
                    
                        C# Language
                        •
                        Async-Await
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Change an existing column’s type
                
            

            
            
To modify an existing column in Rails with a migration, run the following command:
rails g migration change_column_in_table

This will create a new migration file in db/migration directory (if it doesn’t exist already), which will contain the file prefixed with timestamp and migration file name w...            

            
            
                
                    
                        Ruby on Rails
                        •
                        ActiveRecord Migrations
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    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