Introduction

python2ts bridges the gap between AI’s favorite language and the world’s largest ecosystem.

Python dominates AI, ML, and data science. TypeScript powers modern web applications with the npm ecosystem of 3+ million packages. python2ts brings them together — transpile Python to production-ready TypeScript with full type safety.

The Numbers

Metric	Value
Tests	2000+
Python Modules	20+
Dependencies	0 (pythonlib)
Runtimes Supported	4 (Node.js, Bun, Deno, Browser)
Python Features	15+ major constructs

Why python2ts?

AI-First Workflow

Python dominates AI/ML. TypeScript powers modern web apps. Bridge the gap—prototype in Python, deploy anywhere JavaScript runs.

Full Type Safety

Python type hints become TypeScript types automatically. Generics, Protocols, TypedDicts, Callable—all preserved.

20+ Python Modules

itertools, functools, collections, datetime, re, os, pathlib, hashlib, uuid, base64, glob, shutil, tempfile, and more.

Run Everywhere

Node.js, Deno, Bun, browsers, Cloudflare Workers, AWS Lambda—anywhere JavaScript runs, your code runs too.

Two Packages, One Solution

Package	Description	Dependencies
python2ts	The transpiler CLI and API	Minimal
pythonlib	Python standard library for TypeScript (20+ modules)	Zero

Use them together or separately — pythonlib works standalone if you just want Python’s itertools, functools, or collections in TypeScript.

Quick Example

def fibonacci(n: int) -> list[int]:
    """Generate Fibonacci sequence."""
    a, b = 0, 1
    result = []
    for _ in range(n):
        result.append(a)
        a, b = b, a + b
    return result

print(fibonacci(10))

Becomes:

import { range } from "pythonlib"

/**
 * Generate Fibonacci sequence.
 */
function fibonacci(n: number): number[] {
  let [a, b] = [0, 1]
  let result: number[] = []
  for (const _ of range(n)) {
    result.push(a)
    ;[a, b] = [b, a + b]
  }
  return result
}

console.log(fibonacci(10))

What’s in pythonlib?

A comprehensive implementation of Python’s most useful modules:

Core Utilities

Module	Highlights
itertools	combinations, permutations, product, chain, cycle, groupby
functools	lruCache, partial, reduce, pipe, compose
collections	Counter, defaultdict, deque, OrderedDict

Data & Time

Module	Highlights
datetime	datetime, date, time, timedelta with full arithmetic
json	loads, dumps with Python-compatible semantics
re	search, match, findAll, sub with named groups

Math & Random

Module	Highlights
math	sqrt, floor, ceil, factorial, gcd, pi, e
random	randInt, choice, shuffle, sample, uniform

File System

Module	Highlights
os	path.join, environ, getcwd, listdir, walk
pathlib	Path class with readText, writeText, glob
glob	Pattern matching for files
shutil	copy, move, rmtree
tempfile	NamedTemporaryFile, TemporaryDirectory

Security & Encoding

Module	Highlights
hashlib	md5, sha256, sha512
base64	b64encode, b64decode, URL-safe variants
uuid	uuid4, uuid1, UUID class

More

Module	Highlights
string	Template, capWords, ASCII constants
subprocess	run, call, checkOutput
urllib	urlparse, urljoin, quote
logging	getLogger, basicConfig, handlers
sys	argv, platform, exit
time	sleep, time, strftime
copy	copy, deepcopy

Supported Python Features

Feature	Status
Functions & type hints	✅
Classes & inheritance	✅
Dataclasses	✅
Generics (TypeVar, Generic)	✅
Protocols	✅
TypedDict	✅
List/dict/set comprehensions	✅
Pattern matching (match)	✅
Async/await	✅
Decorators	✅
Context managers (with)	✅
f-strings	✅
Generators	✅
Walrus operator (:=)	✅
Multiple inheritance	✅

Runtime Support

Tested on every commit:

• Node.js v22, v24
• Bun latest
• Deno v2.x
• Browsers via Playwright (Chrome, Firefox, Safari)

Also works in: Cloudflare Workers, AWS Lambda, Vercel Edge Functions, and any other JavaScript runtime.

Get Started Install python2ts and start transpiling Python to TypeScript.