给下列代码的每一行加上注释：import socket def scan_ports(host, start_port, end_port, protocol='tcp'): for port in range(start_port, end_port + 1): try: if protocol == 'tcp': sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(0.01) result = sock.connect_ex((host, port)) if result == 0: print(f"Port {port} is open") sock.close() elif protocol == 'udp': sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) sock.settimeout(0.01) sock.sendto(b'Ping', (host, port)) data, addr = sock.recvfrom(1024) if data: print(f"Port {port} is open") sock.close() else: print(f"Unsupported protocol {protocol}") return except socket.error: pass if name == 'main': host = '127.0.0.1' start_port = 1 end_port = 1024 protocols = ['tcp', 'udp'] for protocol in protocols: print(f"Scanning {protocol} ports...") scan_ports(host, start_port, end_port, protocol)

# 导入 socket 模块
import socket 

# 定义一个函数用于扫描指定 IP 的端口
def scan_ports(host, start_port, end_port, protocol='tcp'):

    # 循环遍历指定范围内的端口
    for port in range(start_port, end_port + 1):
        try:
            # 如果协议为 tcp，创建 tcp 连接
            if protocol == 'tcp':
                sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                sock.settimeout(0.01)
                result = sock.connect_ex((host, port)) # 尝试连接端口
                if result == 0: # 如果连接成功
                    print(f"Port {port} is open") # 输出端口号
                    sock.close() # 关闭连接
            # 如果协议为 udp，创建 udp 连接
            elif protocol == 'udp':
                sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
                sock.settimeout(0.01)
                sock.sendto(b'Ping', (host, port)) # 发送 Ping 数据包
                data, addr = sock.recvfrom(1024) # 接收数据包
                if data: # 如果接收到数据
                    print(f"Port {port} is open") # 输出端口号
                    sock.close() # 关闭连接
                else:
                    print(f"Unsupported protocol {protocol}") # 协议不支持
                    return
        except socket.error:
            pass

# 如果当前脚本为主程序
if name == 'main':
    host = '127.0.0.1' # 定义扫描的 IP 地址
    start_port = 1 # 定义起始端口号
    end_port = 1024 # 定义结束端口号
    protocols = ['tcp', 'udp'] # 定义扫描的协议类型
    for protocol in protocols:
        print(f"Scanning {protocol} ports...") # 输出正在扫描的协议类型
        scan_ports(host, start_port, end_port, protocol) # 调用扫描函数进行扫描