Tutorial by Examples: is

Consider the dataframes left and right left = pd.DataFrame([['a', 1], ['b', 2]], list('XY'), list('AB')) left A B X a 1 Y b 2 right = pd.DataFrame([['a', 3], ['b', 4]], list('XY'), list('AC')) right A C X a 3 Y b 4 join Think of join as wanting to combine to dat...

When some programmers see this advice: "Testing strings using == is incorrect (unless the strings are interned)" their initial reaction is to intern strings so that they can use ==. (After all == is faster than calling String.equals(...), isn't it.) This is the wrong approach, from...

Before reading this example, it is required to have a brief idea on edge-relaxation. You can learn it from here Bellman-Ford Algorithm is computes the shortest paths from a single source vertex to all of the other vertices in a weighted digraph. Even though it is slower than Dijkstra's Algorithm, i...

Adjacency list is a collection of unordered lists used to represent a finite graph. Each list describes the set of neighbors of a vertex in a graph. It takes less memory to store graphs. Let's see a graph, and its adjacency matrix: Now we create a list using these values. This is called adjacen...

For this example, we want to make sure that any Employee who is marked as a Project Resource also has an appropriate Labor Cost defined. // 1.0, Revealing Module pattern var myNamespace = myNamespace || {}; myNamespace.example = (function () { /** * User Event 1.0 example detailing...

The puppet agent is a service that runs on the servers. Once the service is started, The agent will be triggered on background every 30 min (by default). The agent have 2 main usages: Send server`s facts to the puppet master Receive catalog from the puppet master ans apply it

It's possible to make a simple lazily-evaluated list using mutable types and closures. A lazily-evaluated list is a list whose elements are not evaluated when it's constructed, but rather when it is accessed. Benefits of lazily evaluated lists include the possibility of being infinite. import Base:...

The typical Visitor example in Java would be: interface ShapeVisitor { void visit(Circle c); void visit(Rectangle r); } interface Shape { void accept(ShapeVisitor sv); } class Circle implements Shape { private Point center; private double radius; public Circl...

In order to emphasize text the command \emph can be used which usually displays the text in an italics font: This is some text with \emph{emphasized words}.

Here is a simple Sprite-Kit GameScene.swift. Create a new, empty SpriteKit project and replace the GameScene.swift with this. Then build and run. Click on any of the objects on screen to give make them move. Check the logs and the comments to see which ones collide and which ones make contact. // ...

;;Recursively print the elements of a list (defun print-list (elements) (cond ((null elements) '()) ;; Base case: There are no elements that have yet to be printed. Don't do anything and return a null list. (t ;; Recursive case ;; Print the next elem...

You can technically access the Google Analytics APIs using any programing language that can handle a HTTP Post or HTTP Get request. That being said, Google has also created a number of official standard client libraries to help you with this. Using a standard client library for your chosen programm...

Unlike normal Rust references, raw pointers are allowed to take null values. use std::ptr; // Create a const NULL pointer let null_ptr: *const u16 = ptr::null(); // Create a mutable NULL pointer let mut_null_ptr: *mut u16 = ptr::null_mut();

Rust has a default formatter for pointer types that can be used for displaying pointers. use std::ptr; // Create some data, a raw pointer pointing to it and a null pointer let data: u32 = 42; let raw_ptr = &data as *const u32; let null_ptr = ptr::null() as *const u32; // the {:p} mappi...

There are quite a number situations where one has huge amounts of data and using which he has to classify an object in to one of several known classes. Consider the following situations: Banking: When a bank receives a request from a customer for a bankcard, the bank has to decide whether to issue...

Data Visualization is an art of presenting the data in a manner that even a non-analyst can understand it. A perfect blend of aesthetic elements like colors, dimensions, labels can create visual masterpieces, hence revealing surprising business insights which in turn helps businesses to make informe...

Instances have a lot of metadata that gets returned from a call to describe-instances, but often times you just want to see the basics. You can use a JMESPath query combined with table output to show concise instance information in an easily readable way. aws ec2 describe-instances --output table -...

ghci> :set -XOverloadedStrings ghci> import Data.Text as T isInfixOf :: Text -> Text -> Bool checks whether a Text is contained anywhere within another Text. ghci> "rum" `T.isInfixOf` "crumble" True isPrefixOf :: Text -> Text -> Bool checks whether a...

Git config allows you to customize how git works. It is commonly used to set your name and email or favorite editor or how merges should be done. To see the current configuration. $ git config --list ... core.editor=vim credential.helper=osxkeychain ... To edit the config: $ git config &lt...

You can use an else clause for code that will be run if no error is raised. def divide(x, y) begin z = x/y rescue ZeroDivisionError puts "Don't divide by zero!" rescue TypeError puts "Division only works on numbers!" return nil rescue => e ...