老师您好!麻烦您帮我看看这个错误是怎么回事?
from socket import *
import struct
filename = input("请输入一个文件名:")
server_ip = "192.168.3.72"
send_data = struct.pack("!H%dsb5sb"%len(filename), 1, filename.encode(), 0, "octet".encode(), 0)
s = socket(AF_INET, SOCK_DGRAM)
s.sendto(send_data, (server_ip, 69))
wenjianjia = open(filename, "ab")
while True:
recv_data = s.recvfrom(1024)
caozuoma, ack_num = struct.unpack("!HH", recv_data[0][:4])
rand_port = recv_data[1][1]
if caozuoma == 5:
print("无法查找到文件")
print("操作码:%d,ACK:%d,端口号:%d,数据长度:%d"%(caozuoma, ack_num, rand_port,len(recv_data[0])))
wenjianjia.write(recv_data[0][4:])
if len(recv_data[0]) < 516:
print("文件下载完毕")
ack_data = struct.pack("!HH", 4, ack_num)
s.sendto(ack_data, (server_ip, ack_num))
