创建线程池，并进行调用

以下是一个基本的线程池实现示例：

import threading
import queue

class ThreadPool:
    def __init__(self, num_threads):
        self.task_queue = queue.Queue()
        self.threads = []
        for i in range(num_threads):
            self.threads.append(threading.Thread(target=self.worker_thread))
    
    def start(self):
        for thread in self.threads:
            thread.start()
    
    def stop(self):
        for i in range(len(self.threads)):
            self.task_queue.put(None)
        for thread in self.threads:
            thread.join()
    
    def submit(self, task):
        self.task_queue.put(task)
    
    def worker_thread(self):
        while True:
            task = self.task_queue.get()
            if task is None:
                break
            task()

使用示例：

def print_hello():
    print("Hello from thread {}".format(threading.current_thread().name))

pool = ThreadPool(4)
pool.start()

for i in range(10):
    pool.submit(print_hello)

pool.stop()

输出：

Hello from thread Thread-1
Hello from thread Thread-3
Hello from thread Thread-2
Hello from thread Thread-4
Hello from thread Thread-1
Hello from thread Thread-3
Hello from thread Thread-2
Hello from thread Thread-4
Hello from thread Thread-1
Hello from thread Thread-3