Python to Javascript

Free Python to Javascript Code Converter

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Transform your code from Python to Javascript with our free AI-based code convertion tool. If you like what you see, we also create documentation for your code! We don't ever store your code or any representation of it in our databases, but it will be shared with the LLM of our choice for processing.

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How to convert from Python to Javascript


Converting code from one programming language to another can be a daunting task, especially when the languages have different syntax and paradigms. This guide will focus on converting Python code to Javascript, helping you make the transition smoother while addressing common issues you might encounter along the way.

Understanding Syntax Differences

Python and Javascript are both high-level, interpreted languages, but their syntax differs significantly. In Python, indentation is crucial as it defines the scope. Javascript, on the other hand, uses curly braces {} to define scope. Below is a basic example to illustrate the difference:

Python Code:

def greet():
    print("Hello, World!")

Javascript Code:

function greet() {
    console.log("Hello, World!");

Variable Declarations

In Python, variable declaration is simple and doesn't require a keyword. However, in Javascript, you have to use var, let, or const:

Python Code:

x = 10

Javascript Code:

let x = 10;

Data Types and Structures

Python has a rich set of built-in data types like lists, tuples, and dictionaries. Javascript has its counterparts called arrays and objects.

Lists and Arrays

In Python, you manage collections using lists:

my_list = [1, 2, 3, 4, 5]

In Javascript, you use arrays:

let myArray = [1, 2, 3, 4, 5];

Dictionaries and Objects

Python dictionaries are akin to Javascript objects:

my_dict = {'name': 'Alice', 'age': 25}
let myObject = {name: 'Alice', age: 25};

Function Definitions

In Python, defining a function is straightforward using the def keyword:

def add(a, b):
    return a + b

In Javascript, functions are defined using the function keyword:

function add(a, b) {
    return a + b;

Conditional Statements

Both Python and Javascript have similar structures for conditional statements but differ in syntax:

Python Code:

if x > 10:
    print("x is greater than 10")
    print("x is not greater than 10")

Javascript Code:

if (x > 10) {
    console.log("x is greater than 10");
} else {
    console.log("x is not greater than 10");


Both languages offer for and while loops, with a noticeable difference in syntax:

Python Code:

for i in range(5):

Javascript Code:

for (let i = 0; i < 5; i++) {

List Comprehensions vs. Array Methods

Python’s list comprehensions are a powerful feature that you don’t find directly in Javascript. Instead, you use array methods like map, filter, and reduce.

Python List Comprehension:

squared = [x**2 for x in range(10)]

Javascript using map:

let squared = Array.from({length: 10}, (v, i) => i ** 2);

Handling Exceptions

Exception handling in Javascript uses try, catch, and finally blocks, similar to Python’s try, except, and finally.

Python Code:

    result = 10 / 0
except ZeroDivisionError:
    print("Cannot divide by zero")
    print("Execution complete")

Javascript Code:

try {
    let result = 10 / 0;
} catch (e) {
    console.log("Cannot divide by zero");
} finally {
    console.log("Execution complete");

Libraries and Frameworks

While Python has a plethora of libraries for every conceivable task (e.g., NumPy, Pandas), Javascript has an equivalent library ecosystem, notably Lodash, Moment.js, and frameworks like React and Angular.


Converting Python code to Javascript involves understanding the fundamental differences in syntax, data structures, and paradigms. While the shift might seem challenging initially, with practice and continual learning, the process becomes more intuitive. This guide serves as a starting point, but always test your converted code to ensure it behaves as expected.

Use this as your go-to guide whenever you're faced with the task of converting from Python to Javascript, simplifying the process and making your transition less stressful. By appreciating the differences and leveraging the strengths of both languages, you can become proficient in both, opening up new possibilities and opportunities in your programming journey.

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