Reference library

Python Code Samples

Medium snippets you can copy, study, and run in the browser editor.

2 matches
API design & gRPC medium

How to Implement ETag Optimistic Concurrency in Python

Build a lightweight in-memory resource store that uses MD5 hash ETags to prevent lost updates via optimistic concurrency control.

etag concurrency hashing
Python
import hashlib
import json

class ResourceStore:
    def __init__(self):
        self.data = {}
        self.etags = {}

    def get(self, resource_id):
        if resource_id not in self.data:
            return None, None
        return self.data[resource_id], self.etags[resource_id]

    def put(self, resource_id, …
13 0 Open
API design & gRPC medium

Implement If-Match Precondition Update in Python

A mock resource store that uses the If-Match header's ETag to guard updates, preventing overwrites from stale clients.

api etag optimistic-concurrency
Python
from dataclasses import dataclass
from typing import Optional


@dataclass
class Resource:
    id: str
    version: int = 1
    data: str = ""
    etag: str = "etag-1"


class MockResourceStore:
    def __init__(self):
        self.resources = {}

    def update(self, resource_id: str, new_data: str, if_match: Optiona…
13 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.