Python what approach is the best – "list of Task objects" or "class Tasks with variable list of elements"

Question

I want to implement a list of tasks, but I don’t know which approach of the two is the best:

First:

class Tasks(object):

    def __init__(self) -> None:
        self.tasks = []

    def add(self, process, instance) -> None:
        self.tasks.append((process, instance, Result()))

# example usage:
tasks = Tasks()
tasks.add('process-1', 'instance-1')

or maybe:

class Task(object):

    def __init__(self, process, instance) -> None:
        self.process = process
        self.instance = instance
        self.result = Result()

# example usage:
tasks = []
task = Task('process-1', 'instance-1')
tasks.append(task)

The goal is to keep somewhere processes and their results when doing parallel tasks (multiprocessing library). Maybe some way is more pythonic? or just more OOP.

Asked By: Alraku

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Answer 1

Highly opinionated, and probably more suited for Software Engineering SE, but each has its own advantages and disadvantages.

The first one is supposedly easier to use and a more "OOP" fashion, but I dislike it for various reasons: It restricts your containers to that specific task list, it’s harder to extend, and you lose a lot of built-in list operations when using that structure (if you don’t inherit from collections.abc.MutableSequence).

The second one is more akin to anemic object model. Some consider this to be an anti-pattern but I find numerous advantages in this approach here:

You have the builtin list capabilities.
Your task object is simple and can be extended / subclassed.
You can easily switch the container (set, list, tuple…).
Easier to handle multi-threading and multi-processing when the container object does not need to guard against such concurrent operations.

Answered By: Bharel

Python what approach is the best – "list of Task objects" or "class Tasks with variable list of elements"

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