Eel is a Python library for making simple offline HTML/JS GUI apps, with full access to Python capabilities and libraries. Eel hosts a local webserver, then lets you annotate functions in Python so that they can be called from Javascript, and vice versa.
Installation
To install this module type the below command in the terminal.
pip install eel
Getting Started
First, create a project folder and make another folder called web under it. The web folder consists of all the website files. Create a main.py python file outside the web folder inside project folder.
This should build a folder like below :
Files and Folders
To use eel in the frontend javascript. Include the following code in the HTML file :
<script type=”text/javascript” src=”/eel.js”></script>
Including this library creates an eel object which can be used to communicate with the Python side. Any functions in the Python code which are decorated with @eel.expose like this:
@eel.expose
def function():
Any python function that is exposed using eel.expose can be called in the javascript like below :
eel.python_function_name()(callback);
Below is an example in which python has a function random_python which returns a random number between 1 and 100, Javascript calls the and then grabs the returned number and changes a div’s innerHTML.
The HTML file here is used to create a window that displays all the required attributes, the javascript file will be called by the HTML file to add dynamism to the window created. Python code is used to make this all work.
HTML file :
HTML
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" /> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta name="viewport" content="width=device-width, initial-scale=1.0" /> <title>Eel Example</title> <style> h1{ color: green; text-align: center; } .random_number{ margin: 50px; font-size: 150px; text-align: center; } button{ display: block; margin: 0 auto; } </style> </head> <body> <h1>Geeks for Geeks</h1> <div class="random_number"></div> <button>Get a Random number using Python</button> <script type="text/javascript" src="../eel.js"></script> <script src="./script.js"></script> </body> </html> |
script.js :
Javascript
// Onclick of the button document.querySelector("button").onclick = function () { // Call python's random_python function eel.random_python()(function(number){ // Update the div with a random number returned by python document.querySelector(".random_number").innerHTML = number; }) } |
The main.py contains :
Python3
import eel from random import randint eel.init("web") # Exposing the random_python function to javascript @eel.expose def random_python(): print("Random function running") return randint(1,100) # Start the index.html file eel.start("index.html") |
Output :
Note: Here the javascript is calling the python function, when python returns the data it changes the div text.
