Why Python Multiprocessing Requires target=func Without Parentheses

1. Introduction

Hello, I'm Pipi. Yesterday in the Python Diamond group I asked a question about Python multiprocessing; the discussion screenshot is shown below.

The following are the execution screenshots:

2. Implementation

User dcpeng provided a solution, as shown below.

Key point: when creating a thread or process, the target argument should be the function name without parentheses.

1. Without parentheses, the function object itself is passed, so the thread starts the function without waiting for its return.

2. With parentheses (and required arguments), the function is called immediately and its return value is used, so the thread must wait for the function to complete.

3. Summary

This article covered a basic Python multiprocessing issue, providing detailed analysis and code implementation to help readers solve the problem.