Reference library

Streaming & messaging

Kafka-style pub/sub, event consumers, async pipelines, and message-driven workflows.

27 matches

Mock Watermark Late Event Side Output in Python

Simulates watermarking in a streaming pipeline by classifying events as on-time or late using timestamps and delays.

from datetime import datetime, timedelta
from typing import List, Tuple


def watermark_mock(
    events: List[Tuple[datetime, str]], watermark_delay: timedelta, max_delay: timedelta
) -> Tuple[List[Tuple[datetime, str]], List[Tuple[datetime, str]]]:
    """Simulate watermarking: events arriving on time vs. late by ch…

11 0 Open

Streaming & messaging easy

Redis Pub/Sub Channel Subscribe Mock in Python

A lightweight in-memory mock of Redis pub/sub that lets you subscribe to channels, publish messages, and verify handler behavior in tests without a real Redis server.

redis pubsub testing

Python

class MockRedisPubSub:
    def __init__(self):
        self.channels = {}

    def subscribe(self, channel):
        if channel not in self.channels:
            self.channels[channel] = []
        return self.channels[channel]

    def publish(self, channel, message):
        if channel in self.channels:
            …

11 0 Open

Streaming & messaging easy

Sliding Window Average with Deque in Python

Computes the running average of a sliding window over streaming numbers using a collections.deque for O(1) pop-left operations.

sliding-window deque streaming

Python

from collections import deque

class SlidingAverage:
    def __init__(self, window_size):
        self.window_size = window_size
        self.window = deque()
        self.total = 0

    def add(self, value):
        self.window.append(value)
        self.total += value
        if len(self.window) > self.window_size:
…

13 0 Open

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