编写代码扫描UDP端口

下面是使用Python编写的扫描UDP端口的代码示例：

import socket

target_host = input("Enter the target host: ")
target_port = int(input("Enter the target port: "))

# create a UDP socket object
client = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

# set a timeout for the socket
client.settimeout(2)

# send a message to the target host and port
client.sendto(b"Test message", (target_host, target_port))

try:
    # receive data from the target host and port
    data, addr = client.recvfrom(4096)
    print("UDP port {} is open".format(target_port))
except socket.timeout:
    print("UDP port {} is closed".format(target_port))

在上面的代码中，我们首先获取目标主机和端口号。然后，我们创建一个UDP socket对象并设置超时时间为2秒。接着，我们向目标主机和端口发送一个测试消息。如果我们能够收到来自目标主机和端口的回复，则说明该端口是开放的。否则，该端口是关闭的。