Python Code
Samples
Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.
Microkernel Plug-in Core Mock in Python
Implements a minimal microkernel plug-in core that registers, unregisters, and executes synchronous or asynchronous plugins via a pluggable manager class.
import json
import abc
import inspect
class MicrokernelCore(abc.ABC):
def __init__(self):
self._plugins = {}
def register(self, name, plugin):
self._plugins[name] = plugin
def unregister(self, name):
return self._plugins.pop(name, None)
def execute(self, name, *args, **kwa…Object Pool Pattern for Database Connections in Python
Implements a reusable connection pool with acquire/release and context manager support, mocking database connections with idle reuse and exhaustion handling.
import time
from contextlib import contextmanager
from collections import deque
class ConnectionPool:
def __init__(self, size=3, max_idle=5):
self._idle = deque(maxlen=max_idle)
self._active = set()
self.size = size
def _create(self):
return {"created_at": time.time(), "queri…Singleton Config Loader in Python with Caution
Implements a singleton config loader in Python that reads JSON config files, but demonstrates the hidden gotcha of shared state across instances.
import json
from pathlib import Path
class ConfigLoader:
_instance = None
def __new__(cls, *args, **kwargs):
if cls._instance is None:
cls._instance = super().__new__(cls)
return cls._instance
def __init__(self, config_file="config.json"):
if not hasattr(self, "loaded…Template Method Workflow Steps Base Class in Python
Define a reusable workflow skeleton in a base class and let subclasses fill in each step with the Template Method design pattern.
from abc import ABC, abstractmethod
class DataPipeline(ABC):
"""Template Method pattern: defines a workflow skeleton."""
def run(self):
"""Template method - defines the algorithm's structure."""
result = {"extracted": False, "transformed": False, "loaded": False}
raw_data = self._ext…CQRS with Separate Read and Write Repositories in Python
Implement CQRS in Python with separate write and read repositories, using commands for mutations and frozen DTOs for queries.
from dataclasses import dataclass
from typing import Dict, List, Optional
# --- Write side: commands mutate state ---
@dataclass
class CreateUserCommand:
id: int
name: str
class UserWriteRepository:
def __init__(self) -> None:
self._store: Dict[int, Dict[str, object]] = {}
def create(self,…How to Use the Adapter Pattern to Mock a Legacy System in Python
This code demonstrates the Adapter pattern, allowing a modern interface to interact with a legacy system by wrapping its outdated method.
class LegacySystem:
def legacy_method(self, data):
return f"Legacy processed: {data}"
class ModernInterface:
def process(self, data):
raise NotImplementedError
class Adapter(ModernInterface):
def __init__(self, legacy):
self.legacy = legacy
def process(self, data):
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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.
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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.