Tutorial by Examples: p

Detecting missing values with np.nan

If you want to detect missings with df=pd.DataFrame({'col':[1,np.nan]}) df==np.nan you will get the following result: col 0 False 1 False This is because comparing missing value to anything results in a False - instead of this you should use df=pd.DataFrame({'col':[1,np.nan]}) ...

pandas • Gotchas of pandas

Different ways to Select from DropDown list

Below is and HTML page <html> <head> <title>Select Example by Index value</title> </head> <body> <select name="Travel"><option value="0" selected> Please select</option> <option value="1">Car</option&...

selenium-webdriver • Select Class

A basic flask blueprints example

A minimal Flask application looks something like this: from flask import Flask app = Flask(__name__) @app.route("/") def index(): return "Hello World!" A large Flask application can separate one file into multiple files by blueprints. Purpose Make it easier for ...

Flask • Blueprints

One way to report about exceptions on iOS

Go to Main.cs file in iOS project and change existed code, like presented below: static void Main(string[] args) { try { UIApplication.Main(args, null, "AppDelegate"); } catch (Exception ex) { Debug.WriteLine(...

Xamarin.Forms • Exception handling

DynamoDB basic Crud Operation using NodeJS

let doc = require('dynamodb-doc'); let dynamo = new doc.DynamoDB(); var tblName = "MyTable"; exports.handler = (event, context, callback) => { readOperation(context); } function readOperation(cnxt) { var params = { TableName: tblName, Key: { "id": ...

amazon-web-services • Amazon DynamoDB

Tracking an extra property on arrays

class MySubClass(np.ndarray): def __new__(cls, input_array, info=None): obj = np.asarray(input_array).view(cls) obj.info = info return obj def __array_finalize__(self, obj): # handles MySubClass(...) if obj is None: pass ...

numpy • subclassing ndarray

Watching the position

For a more real time solution you can use watchPosition function in Geolocation that notifies whenever an error or a position change occurs. Unlike the getCurrentPosition the watchPosition returns an Observable import {Geolocation} from 'ionic-native'; import template from './custom-component.htm...

ionic2 • Geolocation

HTTP GET request

Sometimes a component needs to render some data from a remote endpoint (e.g. a REST API). A standard practice is to make such calls in componentDidMount method. Here is an example, using superagent as AJAX helper: import React from 'react' import request from 'superagent' class App extends Rea...

React • React AJAX call

Introductory Example on Boost.Python

Things are easy when you have to use a C++ library in a Python project. Just you can use Boost. First of all here is a list of components you need: A CMakeList.txt file, because you're going to use CMake. The C++ files of the C++ project. The python file - this is your python project. Let's...

boost • Using boost.python

Alert basic example

<div class="container"> <h2>Alerts</h2> <div class="alert alert-success"> <strong>Success!</strong> </div> <div class="alert alert-info"> <strong>Info!</strong> </div> <div ...

twitter-bootstrap • Alert

Behavior Implementation

using System; using System.Collections.Generic; using System.Runtime.InteropServices; using System.Threading.Tasks; using System.Windows; using System.Windows.Controls; using System.Windows.Interactivity; using System.Windows.Media; using System.Windows.Media.Imaging; namespace MyBehavior...

wpf • Supporting Video Streaming and Pixel Array Assignment to an Image Control

Example for data insert or data retrieve from Firebase

Before understand require to follow some setup for project integrate with firebase. Create your project in Firebase Console and download google-service.json file from console and put it in app level module of your project, Follow link for Create Project in console After this we require to...

firebase-database • FirebaseRealtime database with Android

Or patterns

The | operator can be used anywhere within patterns to describe multiple accepted patterns. If there is a captured variable in an or-pattern, it must appear in both its sub-patterns. var match = switch(7) { case 4 | 1: "0"; case 6 | 7: "1"; case _: "2"; ...

haxe • Pattern matching

Use custom middleware + Superagent

This is example has extracted from this boilerplate. Custom middleware: export default function clientMiddleware() { return ({dispatch, getState}) => { return next => action => { if (typeof action === 'function') { return action(dispatch, getState); } ...

redux • Asynchronous Data Flow

Install in Eclipse and Build Hello World

(Tested with ANTLR 4.5.3, Eclipse Neon, ANTLR 4 IDE 0.3.5, and Java 1.8) Download the latest ANTLR. Make sure to get the complete ANTLR Java binaries jar. Save to any appropriate location, for example the folder where other Java libraries are stored. It doesn’t matter where, just remember the loc...

ANTLR • Introduction to ANTLR v4

Ninject Dependency Injection

Dependency resolver is used to avoid tightly-coupled classes, improve flexibility and make testing easy. You can create your own dependency injector (not recomended) or use one of well-written and tested dependency injectors. In this example I am going to use Ninject. Step one: Create dependency re...

asp.net-mvc • Dependency Injection

Difference between Tk and Toplevel

Tk is the absolute root of the application, it is the first widget that needs to be instantiated and the GUI will shut down when it is destroyed. Toplevel is a window in the application, closing the window will destroy all children widgets placed on that window{1} but will not shut down the program...

tkinter • Multiple windows (TopLevel widgets)

Targeting only main WordPress loop

WordPress is applying pre_get_posts filter to literally any loop it generates. It means that all changes we are making in our callback function are applied to all exiting loops. Obviously it is not what we want in most scenarios. In most cases we would like to target only main loop, and only for n...

WordPress • Alternating main loop (pre_get_posts filter)

Simple setup

Setting up the folders This example assumes code to be in src/ and the output to be put into out/. As such the folder structure should look something like example/ |-- src/ | |-- index.js | `-- ... |-- out/ `-- package.json Setting up the packages Assuming a setup npm environment, we...

React • Installation

Using webpack-dev-server

Setup After setting up a simple project to use webpack, babel and react issuing $npm i -g webpack-dev-server will install the development http server for quicker development. Modifying webpack.config.js var path = require('path'); module.exports = { entry: './src/index.js', output: { ...

React • Installation