Tutorial by Examples: me

Let us assume we have the following two DataFrames: In [7]: df1 Out[7]: A B 0 a1 b1 1 a2 b2 In [8]: df2 Out[8]: B C 0 b1 c1 The two DataFrames are not required to have the same set of columns. The append method does not change either of the original DataFrames. Inst...

It is sometimes useful to integrate a custom error logging framework to ensure all exceptions are logged. [ServiceContract] [ErrorHandler] public interface IMyService { } [AttributeUsage(AttributeTargets.Interface)] public class CustomErrorHandler : Attribute, IContractBehavior, IE...

To be able do deal with form events, it's important to attach the request, that is send to a controller action after submitting a form, to the form created in that action. public function registerAction(Request $request) { $data = new ExampleObject(); $form = $this->createForm(Example...

QObjects come with their own alternative lifetime concept compared to native C++'s raw,unique or shared pointers. QObjects have the possibility to build an objecttree by declaring parent/child relationships. The simplest way to declare this relationship is by passing the parent object in the const...

Of course you can pass data to Sinatra routes, to accept data in your routes you can add route paremeters. You can then access a params hash: get '/hello/:name' do # matches "GET /hello/foo" and "GET /hello/bar" # params['name'] is 'foo' or 'bar' "Hello #{params['...

This example adds a new parameter to MyTestFunction if $SomeUsefulNumber is greater than 5. function MyTestFunction { [CmdletBinding(DefaultParameterSetName='DefaultConfiguration')] Param ( [Parameter(Mandatory=$true)][int]$SomeUsefulNumber ) DynamicParam {...

// Main frame class declaration class CMainFrame : public CMDIFrameWndEx { DECLARE_DYNAMIC(CMainFrame) protected: // declare our pane CDockablePane m_wndPane; // .... other class memebers public: CMainFrame(); protected: afx_msg int OnCreate(LPCREATEST...

If you want to make a change that you want to merge with master, the best way is to first create a topic branch git checkout -b foo make a single commit with your feature git commit -m "Made the thing X finally work" and push that branch to review via git push origin foo:refs/for/...

Because of how gerrit relies on change-ids, in order to resolve conflicts (pull changes to your topic branch) the best practice is to rebase topic branch onto master/other branch you want to push to. This way you preserve the change-id without having to ammend the merge commit. For example if you su...

Some times application must have panes that docked not to the main frame, but to the child frame. Usually it's MDI application. In MFC Feature pack such child frame is inherited from CMDIChildWndEx class and as main frame (inherited from CMDIFrameWndEx) have all required code for such docking. But ...

The following example will return the byte[] data of a zipped file containing the files provided to it, without needing access to the file system. public static byte[] ZipFiles(Dictionary<string, byte[]> files) { using (MemoryStream ms = new MemoryStream()) { using (ZipArc...

If you are using UIViewControllerContainment there are a few other methods that are worth looking at. When you want a child viewController to control the presentation of the status bar (i.e. if the child is positioned at the top of the screen in Swift class RootViewController: UIViewController { ...

Prerequisites: Apple Developers Account Setup GameCenter Leaderboards with iTunesConnect Setting up GameCenter Leaderboards: Sign in to iTunesConnect Go to My Apps. Create an app for your project then go to Features. Click on Game Center Click the plus sign next to Leaderboards. Choose...

public static Expression<Func<T, bool>> GetExpression<T>(IList<QueryFilter> filters) { Expression exp = null; // Represents a named parameter expression. {parm => parm.Name.Equals()}, it is the param part // To create a ParameterExpression need the ty...

ConstantExpression must be the same type of the MemberExpression. The value in this example is a string, which is converted before creating the ConstantExpression instance. private static ConstantExpression GetConstant(Type type, string value) { // Discover the type, convert it, and create Co...

If you want to append a series of values [1,2] to the column of dataframe df, you will get NaNs: import pandas as pd series=pd.Series([1,2]) df=pd.DataFrame(index=[3,4]) df['col']=series df col 3 NaN 4 NaN because setting a new column automatically aligns the data by the inde...

Scenario: You need to select an implementation of address validation when a sales order is submitted, and the validator is determined by the country to which the order is shipping. The factory needs to inspect some value passed as an argument to select the correct implementation. First, write an in...

Scenario: You need to resolve a dependency when a method is called, not in the constructor. Solution: Inject an abstract factory into the constructor. When the method is called, it requests the dependency from the abstract factory, which in turn resolves it from the container. (Your class depends o...

Multidimensional arrays follow the same rules as single-dimensional arrays when passing them to a function. However the combination of decay-to-pointer, operator precedence, and the two different ways to declare a multidimensional array (array of arrays vs array of pointers) may make the declaratio...

You should have the basic express-generator template In app.js, add(you can add it anywhere after var app = express.app()): app.post(function(req, res, next){ next(); }); Now in your index.js file (or its respective match), add: router.get('/ajax', function(req, res){ res.render('aj...