Understanding Daemon Threads in Python

According to Python's documentation, a "daemon thread" refers to a thread that, when left alone, allows the Python program to exit. To understand this concept better, let's dive into its significance.

Firstly, each thread inherits its daemonic status from its parent thread. Now, when does a thread as a daemon become significant? Suppose your program consists of multiple threads; one of them is the main thread, and the others are performing background tasks. These background tasks may include operations like sending keepalive packets, garbage collection, or any other non-essential jobs.

In such scenarios, it might be unnecessary for the background tasks to continue running after the main thread exits. It would be more efficient and practical to terminate these threads as soon as the main thread completes its execution. This is where daemon threads come into play.

By setting a thread as a daemon, you're essentially marking it as one that can be safely killed when the non-daemon threads have exited. This eliminates the need to manually keep track of and terminate the background threads, allowing the program to quit cleanly.

So, in short, the main reason to set a thread as a daemon is to enable the program to exit smoothly when only the essential, non-daemon threads are still running. This is useful for background tasks that don't need to persist after the main thread completes its execution.