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Differences in subsetting syntax A data.table is one of several two-dimensional data structures available in R, besides data.frame, matrix and (2D) array. All of these classes use a very similar but not identical syntax for subsetting, the A[rows, cols] schema. Consider the following data stored i...

If you have a string that contains Python literals, such as strings, floats etc, you can use ast.literal_eval to evaluate its value instead of eval. This has the added feature of allowing only certain syntax. >>> import ast >>> code = """(1, 2, {'foo': 'bar'})&quot...

It is not possible to use eval or exec to execute code from untrusted user securely. Even ast.literal_eval is prone to crashes in the parser. It is sometimes possible to guard against malicious code execution, but it doesn't exclude the possibility of outright crashes in the parser or the tokenizer....

Detailed instructions on getting forms set up or installed.

<div class="navbar navbar-inverse navbar-fixed-top"> <div class="container"> <div class="navbar-header"> <!--- vvv Hamburger icon that gets shown when window reaches a certain scale vvv ---> <button type...

using System; using System.Web; using System.Web.Mvc; namespace Example.SDK.Filters { [AttributeUsage(AttributeTargets.Class, Inherited = false, AllowMultiple = false)] public sealed class CustomErrorHandlerFilter : HandleErrorAttribute { public override void OnExceptio...

You can choose between major distributions of LaTeX: TeX Live (Windows, Linux, and OS X), the standard, cross-platform distribution. MacTeX (Mac) A packaged version of TeX Live made for OS X with some Mac-specific tools MiKTeX (Windows) A separate distribution entirely that All distributions...

If a covariant type appears as an output, the containing type is covariant. Producing a producer of Ts is like producing Ts. interface IReturnCovariant<out T> { IEnumerable<T> GetTs(); } If a contravariant type appears as an output, the containing type is contravariant. Produc...

With ASP.NET Core 1.0, the MVC and Web API framework have been merged into one framework called ASP.NET Core MVC. This is a good thing, since MVC and Web API share a lot of functionality, yet there always were subtle differences and code duplication. However, merging these two into framework one ...

LOOP AT itab INTO wa. ENDLOOP. FIELD-SYMBOLS <fs> LIKE LINE OF itab. LOOP AT itab ASSIGNING <fs>. ENDLOOP. LOOP AT itab ASSIGNING FIELD-SYMBOL(<fs>). ENDLOOP. LOOP AT itab REFERENCE INTO dref. ENDLOOP. LOOP AT itab TRANSPORTING NO FIELDS. ENDLOOP. Conditional L...

In Scala operators (such as +, -, *, ++, etc.) are just methods. For instance, 1 + 2 can be written as 1.+(2). These sorts of methods are called 'infix operators'. This means custom methods can be defined on your own types, reusing these operators: class Matrix(rows: Int, cols: Int, val data: Seq[...

To make a custom pipe available application wide, During application bootstrap, extending PLATFORM_PIPES. import { bootstrap } from '@angular/platform-browser-dynamic'; import { provide, PLATFORM_PIPES } from '@angular/core'; import { AppComponent } from './app.component'; import { MyPipe }...

Detailed instructions on getting WSO2 set up or installed. Almost all the WSO2 Products can be started using the wso2server.sh/bat files that can be found in the <Product_Home>/bin folder of each product. When you run the sh/bat script it will star the particular WSO2 product with default set...

The use of null values is strongly discouraged, unless interacting with legacy Java code that expects null. Instead, Option should be used when the result of a function might either be something (Some) or nothing (None). A try-catch block is more appropriate for error-handling, but if the function ...

There are several ways to format and get a string as a result. The .NET way is by using String.Format or StringBuilder.AppendFormat: open System open System.Text let hello = String.Format ("Hello {0}", "World") // return a string with "Hello World" let builder...

Sometimes when you make a game you need to create and destroy a lot of objects of the same type over and over again. You can simply do this by making a prefab and instantiate/destroy this whenever you need to, however, doing this is inefficient and can slow your game down. One way to get around thi...

A topological ordering, or a topological sort, orders the vertices in a directed acyclic graph on a line, i.e. in a list, such that all directed edges go from left to right. Such an ordering cannot exist if the graph contains a directed cycle because there is no way that you can keep going right ...

Detailed instructions on getting magento2 set up or installed.

F|forbidden Similar to Deny, this flag forces the server to immediately return a 403 Forbidden status code to the requesting browser or client for the request. Example: Deny access to requests that end with exe: RewriteRule .exe$ - [F] G|gone If a requested resource was available in the past,...

Unity works with hierarchies in order to keep your project organized. You can assign objects a place in the hierarchy using the editor but you can also do this through code. Parenting You can set an object's parent with the following methods var other = GetOtherGameObject(); other.transform.Se...