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Python Code Samples

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

4 matches
System design patterns medium

How to implement saga orchestration with compensating steps in Python

Orchestrate a distributed transaction across services, rolling back completed steps with compensations when a later step fails.

saga distributed-transactions compensation
Python 
class InventoryService:
    def reserve(self, order_id):
        print(f"[Inventory] Reserving stock for order {order_id}")
        return True

    def compensate(self, order_id):
        print(f"[Inventory] Releasing stock for order {order_id}")


class PaymentService:
    def charge(self, order_id):
        print(f…
14 0 Open
Microservices patterns medium

Saga pattern orchestration with rollback in Python

Orchestrate a distributed transaction with Saga steps and automated compensation rollback on failure.

saga microservices transaction
Python 
import time
import random


class SagaStep:
    def __init__(self, name):
        self.name = name
        self.executed = False

    def execute(self):
        print(f"Executing {self.name}...")
        time.sleep(0.2)
        if random.random() < 0.3:
            raise RuntimeError(f"{self.name} failed")
        sel…
14 0 Open
ML engineering pipelines medium

How to Build a Mock ML Pipeline with Prefect in Python

Create a lightweight Prefect flow with mock preprocessing, training, and evaluation tasks to prototype an ML pipeline end-to-end.

prefect machine-learning pipeline
Python 
from prefect import task, flow
from datetime import datetime


@task
def preprocess_data(raw_value: float) -> float:
    """Mock preprocessing: normalize the input value."""
    return raw_value / 100.0


@task
def train_model(features: float) -> dict:
    """Mock training: return a fake model artifact."""
    return …
12 0 Open
ML engineering pipelines medium

Training Pipeline Orchestration Mock DAG in Python

Build a mock DAG orchestrator that runs ML pipeline stages in dependency order using topological sorting (Kahn's algorithm).

dag pipeline topological-sort
Python 
from collections import deque
from dataclasses import dataclass, field


@dataclass
class DAGNode:
    name: str
    task: callable
    dependencies: list[str] = field(default_factory=list)


class MockDAG:
    def __init__(self, nodes: list[DAGNode]):
        self.nodes = {n.name: n for n in nodes}
        self.execu…
13 0 Open

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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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  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

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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.

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