mpmq

mpmq is a Python package for running the same function across multiple processes while capturing worker log messages in a central message queue. It is built for programs that need controlled parallel execution, per-worker inputs, and a clean way to observe what workers are doing while they run.

Why use mpmq

Raw multiprocessing gives you processes, but you still end up writing glue code for:

• feeding each worker input
• limiting concurrency
• collecting results
• handling worker logs

mpmq handles that for you with a simple, consistent execution model.

What mpmq does

mpmq runs a function across multiple processes, passing each worker its own input and optionally shared data. Worker log messages are routed back to the parent process through a queue, and results are collected when execution completes. You define the work and inputs. mpmq handles process management, concurrency, message forwarding, and result collection.

mpmq is a lightweight wrapper around Python multiprocessing that lets you run a function across multiple processes, centralize worker log messages, and collect results — without writing the plumbing yourself.

Installation

pip install mpmq

MPmq class

mpmq.MPmq(function, process_data=None, shared_data=None, processes_to_start=None)

Parameters

function

Function executed in each worker process.

process_data

List of dictionaries. Each dictionary is passed to one worker. Total length = total executions.

shared_data

Dictionary passed to all workers.

process_to_start

Max number of concurrent workers. Extra work is queued and executed as workers complete.

Methods

execute(raise_if_error=False)

Starts execution and waits for all workers to complete.

Returns a list of results from each worker.

If raise_if_error=True, raises an exception if any worker fails.

process_message(offset, message)

Hook for handling log messages from workers while execution is running.

• offset - index of worker in process_data
• message - logged message

This is the key extension point for building tools like progress displays or terminal UIs.

Examples

The MPmq class is designed to be subclassed. By overriding process_message, you can handle log messages from worker processes as they are received. The example below shows how to do this.

Worker Status as a Progress Bar

The example parallizezes a task across multiple processes using a pool of worker processes. Status of each worker is shown as a Progress Bar, as each Child worker in the pool completes an item defined in the task the Parent updates a Progress Bar.

Worker Status as a List

The example parallizezes a task across multiple processes using a pool of worker processes. Status of each worker is shown using an array where each index of the array represents an individual worker, as each Child worker in the pool completes the associated item in the List is updated with the completed message.

Projects using mpmq

• mpcurses An abstraction of the Python curses and multiprocessing libraries providing function execution and runtime visualization capabilities

• mppbars Scale execution of a function across multiple across a number of background processes while displaying their execution status via a progress bar

• mp4ansi A simple ANSI-based terminal emulator that provides multi-processing capabilities

Development

Clone the repository and ensure the latest version of Docker is installed on your development server.

Build the Docker image:

docker image build \
-t mpmq:latest .

Run the Docker container:

docker container run \
--rm \
-it \
-v $PWD:/code \
mpmq:latest \
bash

Execute the build:

make dev