Reference library

Python Code Samples

Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.

49 matches
Production deployment patterns easy

How to Replace Fields in an Immutable Dataclass in Python

Create a new copy of a frozen dataclass with selected fields changed, leaving the original unchanged.

dataclasses immutable configuration
Python 
from dataclasses import dataclass, replace


@dataclass(frozen=True)
class ServerConfig:
    name: str
    cpu: int = 2
    ram: int = 4096
    tags: tuple = ()


original = ServerConfig("web-01", cpu=4, tags=("env:prod",))
updated = replace(original, ram=8192, tags=("env:prod", "region:us-east"))

print("Original:", …
15 0 Open

Browse by section

Each section groups closely related Python snippets.

Guide: free Python code samples library

Copy-ready Python snippets for learners and developers

PythonSkillset code samples are short, focused examples organised by topic and difficulty. Every snippet is server-rendered HTML — readable by search engines and easy to copy. Open any sample, read the notes, copy the code, then press Try in editor to run it in the browser with Pyodide.

How to use this library

  1. Pick a topic section — strings, lists, files, functions, and more
  2. Open a sample, read How it works, and copy the code block
  3. Run it in the IDE, tweak values, then take a related quiz or tutorial lesson

Samples vs tutorials and challenges

Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.

Related coding tools

Free online Python IDE Write and run Python in your browser — no install. Free Python code formatter Format with autopep8 — side-by-side PEP 8 cleanup.