Python3判断自身脚本是不是在运行

采用Socket方式，启动时占用一个端口，转化问题为判断端口是不是存在？

import sys
import locale
import http.server
import socketserver
import requests
import threading
from time import sleep

addr = 'localhost'
port = 

def BindHttp():
    handler = http.server.SimpleHTTPRequestHandler
    httpd = socketserver.TCPServer((addr, port), handler)
    print("HTTP server is at: http://%s:%d/" % (addr, port))
    httpd.serve_forever()

def CheckRunning():
    tempUrl = 'http://' + addr + ':' + str(port)
    try:
        opener = urllib.request.build_opener()
        opener.addheaders = [('User-agent', 'Mozilla/49.0.2')]
        opener.open(tempUrl)
        print('验证端口'+str(port)+'启动正常！')
        return True
    except urllib.error.HTTPError:
        # print('验证端口' + str(port) + '没有启动！错误代码：HTTPError')
        print('验证端口' + str(port) + '没有启动！')
        return False
    except urllib.error.URLError:
        # print('验证端口' + str(port) + '没有启动！错误代码：URLError')
        print('验证端口' + str(port) + '没有启动！')
        return False

if __name__ == '__main__': t = threading.Thread(target=BindHttp) t.setDaemon(True) t.start() print(CheckRunning()) input("\n\nPress the enter key to exit.")