给下列代码加上注释：import socket import queue import threading def scan(host, startPort, endPort): portList = [] q = queue.Queue() for i in range(startPort, endPort+1): q.put(i) def worker(): while not q.empty(): port = q.get() try: s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.settimeout(1) s.connect((host, port)) print("TCP端口{}开放".format(port)) portList.append(port) except: pass try: s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) s.settimeout(1) s.bind((host, port)) print("UDP端口{}开放".format(port)) portList.append(port) except: pass threads = [] for i in range(50): t = threading.Thread(target=worker) threads.append(t) t.start() for t in threads: t.join() portList.sort() return portList def main(): host = "120.46.209.149" startPort = 1 endPort = 1024 step = (endPort // 1000) + 1 for i in range(1, step): start = startPort + (i - 1) * 1000 end = startPort + i * 1000 print("正在扫描{}-{}".format(start, end)) res = scan(host, start, end) print(res) if name == "main": main()

# 导入必要的模块
import socket
import queue
import threading

# 定义扫描函数，接收主机、起始端口和结束端口作为参数
def scan(host, startPort, endPort):
# 创建一个队列
portList = []
q = queue.Queue()
# 将要扫描的端口加入队列
for i in range(startPort, endPort+1):
q.put(i)

# 定义处理队列中端口的函数
def worker():
while not q.empty():
# 从队列中取出一个端口
port = q.get()
try:
# 创建一个 TCP 套接字，尝试连接指定主机和端口
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(1)
s.connect((host, port))
print("TCP端口{}开放".format(port))
# 将开放的端口添加到列表中
portList.append(port)
except:
pass
try:
# 创建一个 UDP 套接字，尝试在指定主机和端口上绑定
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.settimeout(1)
s.bind((host, port))
print("UDP端口{}开放".format(port))
# 将开放的端口添加到列表中
portList.append(port)
except:
pass

# 创建多个线程处理队列中的端口
threads = []
for i in range(50):
t = threading.Thread(target=worker)
threads.append(t)
t.start()

# 等待所有线程结束
for t in threads:
t.join()

# 对开放的端口列表进行排序并返回
portList.sort()
return portList

# 定义主函数
def main():
# 定义要扫描的主机、起始端口和结束端口
host = "120.46.209.149"
startPort = 1
endPort = 1024
# 计算每个线程需要扫描的端口范围
step = (endPort // 1000) + 1
# 分段扫描端口
for i in range(1, step):
start = startPort + (i - 1) * 1000
end = startPort + i * 1000
print("正在扫描{}-{}".format(start, end))
# 扫描指定范围内的端口
res = scan(host, start, end)
print(res)

# 判断是否为主模块并执行主函数
if __name__ == "main":
main()