控件未返回到主线程

Question

我已经编写了一个python程序，其中我在线程1中创建了一个UDP侦听器，并尝试在线程2中执行一些操作。这里的问题是，线程1中的控制被卡住了，它永远不会返回到主线程，因此线程2甚至没有启动

import threading
import socket
import time

data = ''

def ListenerUDP():
    sock1 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    server_address1 = ('localhost', 5000)
    print('starting up UDP server on %s port %s' % server_address1)
    sock1.bind(server_address1)

    while True:
        print('\nUDP server is now listening up')
        data, address = sock1.recvfrom(4096)
        print('received %s bytes from %s' % (len(data), address))
        print('is %s' % data.hex())


def Forwarder():
    print('do something')


print('Starting main thread')

t1 = threading.Thread(target=ListenerUDP)
t1.start()

t2 = threading.Thread(target=Forwarder)
t2.start()

谁能帮我修一下吗