ReflexKR

Python that clicks
when you click it

From Reflex web apps to regex, asyncio and algorithms. The examples here aren't screenshots; they're real code running on this page right now. Start by playing with the one next to this.

for m in re.finditer(r"\d{2,3}-\d{3,4}-\d{4}", text):

print(m.group())

Pattern

Text

Call 010-1234-5678 or 02-555-0199. Office hours 9:30-18:00.

2 matches

This example runs as real Python code on the server.

Build web apps with Reflex

Build the UI and the server together, in Python alone.

Reflex Basics, Hands-On

Start with a single button and work up to State, events, conditions, lists and compile time. A 40-minute course where every example is live

6 lessons40 min

Full-Stack Python Web Development with Reflex

A 4-hour beginner course: build a customer management app in a single Python file

6 lessons4 hours

The Component Workshop: Reflex's 100 Library Components

All 100 components in the official Reflex library, one page each. A hands-on field guide: change the props and watch the screen and the Python code change together.

100 components100 components

Intermediate Python

The step after the basics: the object model, regular expressions, asyncio and other practical skills.

Name Tag Airport: Python's Object Model

Join the baggage center at Haneulseom International Airport as its new tag handler and solve twelve lost-baggage cases, watching names, objects, references, scopes, classes and memory on a live tag board. A 10-hour course.

12 lessons10 hours

Regular expressions you can see

Join Grep & Co., a data detective agency, as its newest detective and learn every piece of Python's re syntax by cracking 12 cases in 10 hours.

12 lessons10 hours

Concurrency in the Late-Night Kitchen

Become the new sous-chef at the late-night diner Dongsi and learn threading, multiprocessing and asyncio over twelve services, watching every task on a live kitchen timeline. A 10-hour course.

12 lessons10 hours

Math for developers

Build intuition with pictures, then compute the same ideas yourself with NumPy.

Linear Algebra You Can See, with NumPy

Fifteen lessons for developers who opened a linear algebra book and closed it again. Drag basis vectors, watch the grid bend, then compute the same ideas with NumPy, all the way to determinants, eigenvalues, SVD and PCA.

15 lessons12.5 hours