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Streaming & messaging

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

3 matches

How to Read Redis Streams with XREADGROUP in Python

Read new messages from a Redis stream using a consumer group with XREADGROUP, handling JSON payloads and group creation.

redis streams consumer groups

Python

import redis
import json

def read_group_messages(stream_key, group_name, consumer_name, count=10):
    r = redis.Redis(host="localhost", port=6379, decode_responses=True)
    try:
        r.xgroup_create(stream_key, group_name, id="0", mkstream=True)
    except redis.exceptions.ResponseError:
        pass

    messag…

12 0 Open

Streaming & messaging easy

How to Serialize and Deserialize JSON Event Payloads in Python

Define an EventPayload class with custom to_json and from_json methods to convert event objects to JSON strings and back, using datetime parsing.

json serialization datetime

Python

import json
from datetime import datetime


class EventPayload:
    def __init__(self, event_id, event_type, timestamp, data):
        self.event_id = event_id
        self.event_type = event_type
        self.timestamp = timestamp
        self.data = data

    def to_json(self):
        return json.dumps({
          …

12 0 Open

Streaming & messaging easy

Using the retained message flag in MQTT with Python

This script subscribes to an MQTT topic and prints the retained flag for each received message, demonstrating how to distinguish retained messages from normal ones.

mqtt paho-mqtt iot

Python

import paho.mqtt.client as mqtt

def on_connect(client, userdata, flags, rc):
    print(f"Connected with result code {rc}")
    # Subscribe to a topic and check retained flag
    client.subscribe("test/retained")
    print("Subscribed to test/retained")

def on_message(client, userdata, msg):
    # msg.retain is the M…

14 0 Open

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