关于多线程的程序如何在主线程中捕获键盘中断信号

sweetarea

大家好，我学习异步编程的时候，遇到下面的这段代码:

[Python] 纯文本查看 复制代码

from threading import Thread
import socket


class ClientEchoThread(Thread):

    def __init__(self, client):
        super().__init__()
        self.client = client

    def run(self):
        try:
            while True:
                data = self.client.recv(2048)
                if not data: #A
                    raise BrokenPipeError('Connection closed!')
                print(f'Received {data}, sending!')
                self.client.sendall(data)
        except OSError as e: #B
            print(f'Thread interrupted by {e} exception, shutting down!')

    def close(self):
        if self.is_alive(): #C
            self.client.sendall(bytes('Shutting down!', encoding='utf-8'))
            self.client.shutdown(socket.SHUT_RDWR) #D


with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as server:
    server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    server.bind(('127.0.0.1', 8000))
    server.listen()
    connection_threads = []
    try:
        while True:
            connection, addr = server.accept()
            thread = ClientEchoThread(connection)
            connection_threads.append(thread)
            thread.start()
    except KeyboardInterrupt:
        print('Shutting down!')
        [thread.close() for thread in connection_threads] #E

当运行环境是windows，在cmd中python 运行它，启动后在命令行中无法输入CTRL＋C。


但是如果换成下面的代码就可以正常捕获键盘中断信号。

[Python] 纯文本查看 复制代码

import time


def main():
    print('before ...')
    time.sleep(20)
    print('after ...')


if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        print('\nKeyboardInterrupt ...')
    print('the end')

请问为什么第一段程序无法捕捉到键盘中断信号CTRL＋C了？该如何改写在 try 中的循环中能触发 KeyboardInterrupt 了？