【Python】プロセスの中で子スレッドを作成【並列処理】

import os
import time
import threading
from threading import Thread

def cpu_waster(i: int) -> None:
    name = threading.current_thread().getName()
    print(f"{name} doing {i} work")
    time.sleep(3)

def display_threads() -> None:
    print("-" * 10)
    print(f"Current process PID: {os.getpid()}")
    print(f"Thread Count: {threading.active_count()}")
    print("Active threads:")
    for thread in threading.enumerate():
        print(thread)

def main(num_threads: int) -> None:
    display_threads()

    print(f"Starting {num_threads} CPU wasters...")
    for i in range(num_threads):
        thread = Thread(target=cpu_waster, args=(i,))
        thread.start()
    
    display_threads()

if __name__ == "__main__":
    num_threads = 5
    main(num_threads)

$ python3 multithreading.py
———-
Current process PID: 580482
Thread Count: 1
Active threads:
<_MainThread(MainThread, started 281472949920800)>
Starting 5 CPU wasters…
Thread-2 (cpu_waster) doing 1 work
Thread-3 (cpu_waster) doing 2 work
Thread-4 (cpu_waster) doing 3 work
/home/vagrant/dev/rust/parallel/python/multithreading.py:7: DeprecationWarning: getName() is deprecated, get the name attribute instead
name = threading.current_thread().getName()
Thread-1 (cpu_waster) doing 0 work
Thread-5 (cpu_waster) doing 4 work
———-
Current process PID: 580482
Thread Count: 6
Active threads:
<_MainThread(MainThread, started 281472949920800)>

うーむ、中々難儀やのう