Reference library

Python Code Samples

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

3 matches
Data pipelines & processing easy

How to Deduplicate Events with At-Least-Once Delivery in Python

Implements an exactly-once processing pattern for at-least-once event delivery by tracking seen event IDs in a set, skipping duplicates.

deduplication idempotent event-processing
Python
seen_ids = set()

def process_event(event_id: str, payload: dict) -> dict:
    """Process an event exactly once, ignoring duplicates."""
    if event_id in seen_ids:
        return {"status": "duplicate", "event_id": event_id}
    seen_ids.add(event_id)
    return {"status": "processed", "event_id": event_id, **payloa…
12 0 Open
Streaming & messaging medium

How to Implement At-Least-Once Delivery with Acknowledgment in Python

This code demonstrates a mock message broker with at-least-once delivery, including retry logic and acknowledgment after successful processing.

messaging queue retry
Python
import time
import uuid
from collections import deque


class MockMessageBroker:
    def __init__(self):
        self.queue = deque()
        self.acked = set()

    def publish(self, payload: str) -> str:
        msg_id = str(uuid.uuid4())
        self.queue.append((msg_id, payload))
        return msg_id

    def po…
13 0 Open
Reliability & rate limiting medium

At Least Once with Idempotent Consumer in Python

Implements a thread-safe idempotent consumer that processes each unique message exactly once, even when a producer sends duplicates under an at-least-once delivery model.

idempotency at-least-once threading
Python
import threading
import time
import uuid
from collections import Counter


class IdempotentConsumer:
    def __init__(self):
        self.processed = set()
        self._lock = threading.Lock()

    def consume(self, message_id, payload):
        with self._lock:
            if message_id in self.processed:
          …
15 0 Open

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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.