python网络编程调用recv函数完整接收数据的三种方法

import socket,struct,sys,time
Port=22220
#assume a socket disconnect (data returned is empty string) means all data was #done being sent.
def recv_basic(the_socket):
 total_data=[]
 while True:
  data = the_socket.recv(20480) 
  if not data: break
  total_data.append(data)
 return ''.join(total_data)

End='something useable as an end marker'
def recv_end(the_socket):
 total_data=[];data=''
 while True:
   data=the_socket.recv(8192)
   if End in data:
    total_data.append(data[:data.find(End)])
    break
   total_data.append(data)
   if len(total_data)>1:
    #check if end_of_data was split
    last_pair=total_data[-2]+total_data[-1]
    if End in last_pair:
     total_data[-2]=last_pair[:last_pair.find(End)]
     total_data.pop()
     break
 return ''.join(total_data)

def recv_size(the_socket):
 #data length is packed into 4 bytes
 total_len=0;total_data=[];size=sys.maxint
 size_data=sock_data='';recv_size=8192
 while total_len<size:
  sock_data=the_socket.recv(recv_size)
  if not total_data:
   if len(sock_data)>4:
    size_data+=sock_data
    size=struct.unpack('>i', size_data[:4])[0]
    recv_size=size
    if recv_size>524288:recv_size=524288
    total_data.append(size_data[4:])
   else:
    size_data+=sock_data
  else:
   total_data.append(sock_data)
  total_len=sum([len(i) for i in total_data ])
 return ''.join(total_data)