#   
## Definition

**Transcrypt** is a transpiler to compile a reasonably large Python code into compact, readable JavaScript. It takes the Python code that you write and converts it into a JavaScript file. That JS file can then be loaded into a web browser, and the code run. 

Notably, no browser plug-in or large JavaScript runtime download is required to run the code. Also, the code is pre-compiled into JavaScript before it is downloaded to the browser, so application performance is not compromised.

## Characteristics

It has the following characteristics:

- It translates relatively large Python scripts into highly readable and easy to debug JavaScript code.

- It is lightweight.

- It offers the semantic essence of Python and the clean syntax that the language is famous for.

- It works seamlessly with the JavaScript world of web-based libraries.

> In two words: it’s *lean* and *mean*.

## Installation required

Transcrypt has been tested under Windows, Linux, and OSX, with Chrome, Internet Explorer and Firefox. Follow the steps outlined below to get started:

- **Step 1:** Go to #key# Python official documentation: https://www.python.org/ #key# and download Python 3.9.

- **Step 2:** Run the command `python -m pip install transcrypt` in the command prompt to install Transcrypt.

- **Step 3:** Make a new folder called `hello` with the files `hello.html` and `hello.py` in it.

- **Step 4:** Run the command `python -m transcrypt -b -m -n hello.py` from inside the new folder.

- **Step 5:** Run the command `python -m http.server` from inside the new folder to start an HTTP server.

- **Step 6:** Go to `localhost:8000/hello.html` in the browser to view the results.




>  The command would be `python39` or `python3` rather than `python` on Windows operating system. You may have to type `python3.9` or `python3` rather than `python` on Linux and macOS systems.  To compile the test program on some systems, you can just type `transcrypt -b -m -n hello.py`.

## Hello, solar system: A test application




We will test a `hello, solar system` application below. For the sake of simplicity, all the installations required are already performed. All you need to do is just click the "Run" button, and after that click the link given after "Your app can be found at":

from itertools import chain

class SolarSystem:
    planets = [list (chain (planet, (index + 1,))) for index, planet in enumerate ((
        ('Mercury', 'hot', 2240),
        ('Venus', 'sulphurous', 6052),
        ('Earth', 'fertile', 6378),
        ('Mars', 'reddish', 3397),
        ('Jupiter', 'stormy', 71492),
        ('Saturn', 'ringed', 60268),
        ('Uranus', 'cold', 25559),
        ('Neptune', 'very cold', 24766) 
    ))]
    
    lines = (
        '{} is a {} planet',
        'The radius of {} is {} km',
        '{} is planet nr. {} counting from the sun'
    )
    
    def __init__ (self):
        self.lineIndex = 0
    
    def greet (self):
        self.planet = self.planets [int (Math.random () * len (self.planets))]
        document.getElementById ('greet') .innerHTML = 'Hello {}'.format (self.planet [0])
        self.explain ()
        
    def explain (self):
        document.getElementById ('explain').innerHTML = (
            self.lines [self.lineIndex] .format (self.planet [0], self.planet [self.lineIndex + 1])
        )
        self.lineIndex = (self.lineIndex + 1) % 3
        
solarSystem = SolarSystem ()

import React from 'react';
import { shallow, configure } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';

configure({ adapter: new Adapter() });

import HelloWorld from './app';

var TestResult = function() {
    this.succeeded = false;
    this.reason = "";
    this.input = "";
    this.expected_output = "";
    this.actual_output = "";
}

export const executeTests = function() {

  var results = [];

  result = new TestResult();
  result.input = 'HelloWorld Component';
  result.expected_output = "span containing text 'Hello World'"

  let wrapper = shallow(<HelloWorld />);

  // Call your Challenge function here.

  let type = wrapper.type();
  let testSuccessful = true;
  let failureReason;

  if (type !== 'span') {
    testSuccessful = false;
    failureReason = "You need to render exactly one span HTML element";
  } else if (wrapper.props().children != "Hello World") {
     testSuccessful = false;
     failureReason = "You have rendered wrong message in your span element";
  }

  result.actual_output = wrapper.html();

  if (testSuccessful) {
    result.succeeded = true;
    result.reason = "Succeeded"
  } else {
    result.succeeded = false;
    result.reason = failureReason;
  }

  results.push(result);

  return results;
}


What is Transcrypt?

Definition

Characteristics

Installation required

Hello, solar system: A test application