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Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.
How to Create a Data Helper Class in Python for JSON Files
Build a beginner-friendly Python helper class to read, write, filter, and summarize JSON data files with clean, reusable methods.
import json
from pathlib import Path
class DataHelper:
"""Simple beginner-friendly helper for reading and writing JSON data files."""
@staticmethod
def read_json(filename):
file_path = Path(filename)
if file_path.exists():
with file_path.open("r", encoding="utf-8") as f:
…How to Simulate a Stable Sort Cursor in Python
Build a MongoDB-style cursor mock that stably sorts records by a key while preserving original order for ties, with next() and rewind() methods.
```python
import random
class CursorStableSortMock:
"""Simulates stable sorting with a cursor-like pointer for MongoDB-style queries."""
def __init__(self, data, sort_key, reverse=False):
self.data = list(data)
self.sort_key = sort_key
self.reverse = reverse
self._index = …How to Mock a Redis Session Store in Python
An in-memory RedisSessionStore class with TTL-based expiry, get/set/delete/exists methods, and JSON field support—perfect for testing and prototyping without a live Redis.
import time
import json
from collections import defaultdict
class RedisSessionStore:
"""In-memory mock of a Redis-backed session store."""
def __init__(self, ttl=3600):
self._data = defaultdict(dict)
self._expires = {}
self._ttl = ttl
def set(self, session_id, field, value):
…How to mock Argon2 password hashing in Python
This code demonstrates a mock Argon2 password hasher using HMAC-SHA256 iterations, providing hash and verify methods that mimic Argon2's salted, iterated derivation.
import hashlib
import hmac
import os
class Argon2Mock:
def __init__(self, salt_size=16, hash_len=32):
self.salt_size = salt_size
self.hash_len = hash_len
def hash(self, password: str, salt: bytes = None) -> str:
if salt is None:
salt = os.urandom(self.salt_size)
…How to Build a Simple Data Helper Class in Python
A beginner-friendly DataHelper class that stores Python dataclass objects as JSON records to disk, with load, add, and save methods.
import json
from dataclasses import dataclass, asdict
from pathlib import Path
@dataclass
class User:
name: str
age: int
email: str
class DataHelper:
def __init__(self, filepath: str = "data.json"):
self.filepath = Path(filepath)
self._data = self._load()
def _load(self) -> l…Browse by section
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Guide: free Python code samples library
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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.
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- Pick a topic section — strings, lists, files, functions, and more
- Open a sample, read How it works, and copy the code block
- 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.