generic-consumer 0.20.2

A generic consumer for Python.

Generic Consumer

A flexible Python library for implementing consumer patterns with a focus on payload processing and queue management.

Overview

Generic Consumer provides a framework for creating consumer classes that can process data payloads from various sources. It supports both synchronous and asynchronous processing with features like:

• Prioritized execution order
• Payload preprocessing
• Conditional activation
• Nested consumer hierarchies
• Robust error handling
• Customizable logging

Installation

Using pip

pip install generic-consumer

Quick Start

from generic_consumer import GenericConsumer

class MyConsumer(GenericConsumer):
    # Set the queue this consumer responds to
    @classmethod
    def queue_name(cls):
        return "my_queue"
    
    # Define where to get payloads from
    def get_payloads(self):
        return [1, 2, 3, 4, 5]
    
    # Process a single payload
    def process_one(self, payload):
        print(f"Processing: {payload}")
        
# Run all consumers for a queue
GenericConsumer.start("my_queue")

Key Features

Consumer Configuration

• queue_name: Define which queue a consumer belongs to
• priority_number: Set execution priority (lower numbers run first)
• condition: Determine whether a consumer should run based on runtime conditions
• enabled: Toggle consumer activation
• process_empty_payloads: Handle cases where no payloads are available
• passive: Create consumers that monitor but don't process (useful for logging)

Processing Pipeline

1. get_payloads: Retrieve data to be processed
2. payload_preprocessors: Transform payloads before processing
3. process: Handle batch processing of all payloads
4. process_one: Process individual payloads

Utility Methods

• start_all/start: Run all consumers for a given queue
• print_available_consumers: Display all registered consumers and their configurations
• run: Execute a specific consumer
• run_all: Execute all consumers

Advanced Usage

Passive Consumers

Use PassiveConsumer for monitoring or logging without modifying data:

from generic_consumer import PassiveConsumer

class LoggingConsumer(PassiveConsumer):
    @classmethod
    def queue_name(cls):
        return "my_queue"
    
    def process(self, payloads):
        print(f"Observed {len(payloads)} items")