Python：同步線程之間的輸入和輸出

Question

目前，我正在嘗試使用Python中的套接字（一種雙用戶聊天系統）做一個小型項目。

import socket 
import threading 

#Callback. Print doesn't work across threads 
def data_recieved(data): 
    print data 

#Thread class to gather input 
class socket_read(threading.Thread): 
    sock = object 
    def __init__(self, sock): 
     threading.Thread.__init__(self) 
     self.sock = sock 
    def run(self): 
     while True: 
      data = self.sock.recv(1000) 
      if (data == "\quitting\\"): 
       return 
      data_recieved(self.sock.recv(1000)) 

#################################################################################### 
server = False 
uname = input("What's your username: ") 
print "Now for the technical info..." 
port = input("What port do I connect to ['any' if first]: ") 
#This is the first client. Let it get an available port 
if (port == "any"): 
    server = True 
    port = 9999 
    err = True 
    while err == True: 
     try: 
      sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
      sock.bind(('', port)) 
      err = False 
     except: 
      err = True 
     sock.close() 

    print "Bound to port #" + str(port) 
    print "Waiting for client..." 

    sock.listen(1) 
    (channel, info) = sock.accept() 
else: 
    #This is the client. Just bind it tho a predisposed port 
    host = input("What's the IP of the other client: ") 
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
    sock.connect((host, int(port))) 

msg = "" 
if (server == True): 
    #Use the connection from accept 
    reader = socket_read(channel) 
else: 
    #Use the actual socket 
    reader = socket_read(sock) 
reader.start() 
while msg != 'quit': 
    #Get the message... 
    msg = uname + ": " + input("Message: ") 
    try: 
     #And send it 
     if (server == True): 
      #Use the connection from accept 
      channel.send(msg) 
     else: 
      #Use direct socket 
      sock.send(msg) 
    except: 
     break 
reader.join() 
channel.send("\quitting\\") 
sock.close() 

（我希望評論幫助）

總之，通過調用輸入的同時，並獲得對方套接字的消息時，我有一個小的同步化問題。我可以連接，但是當我收到消息時，它不會取消輸入語句。

換句話說，當我收到一個消息，它說這個

Message: user: I got a message 
#Flashing cursor here 

因此，它不會取消輸入語句。

此外，我只收到其他所有消息。

有什麼建議嗎？

Answer 1

你在這裏所做的並不是一個同步問題，因爲它是一個演示/ UI問題。我建議讓你的生活更輕鬆，並選擇一些UI工具包（curses，wxPython，pyqt）來處理與用戶的交互。使用input（）對於快速而骯髒的一次性代碼非常方便，但它並不十分複雜。

如果你這樣做，你會看到你根本不需要使用線程（就像往常一樣），你的問題就會像魔術一樣消失！

Answer 2

好吧，對於我自己的問題，很抱歉這麼快速回答，但使用線程時（至少在Linux的模型上），回調是神奇的。

總之，這樣做：

import socket 
import threading 

def msg_loop(socket): 
    msg = "" 
    if (server == True): 
     reader = socket_read(channel) 
    else: 
     reader = socket_read(sock) 
    reader.start() 
    while msg != 'quit': 
     msg = uname + " said : " + input("Message: ") 
     print "" 
     try: 
      if (server == True): 
       channel.send('null') 
       channel.send(msg) 
      else: 
       sock.send('null') 
       sock.send(msg) 
     except: 
      break 

def data_recieved(data, socket): 
    print "Hold on...\n\n" + data + "\n" 
    msg_loop(socket) 

class socket_read(threading.Thread): 
    sock = object 
    def __init__(self, sock): 
     threading.Thread.__init__(self) 
     self.sock = sock 
    def run(self): 
     while True: 
      data = self.sock.recv(1000) 
      if (data == "\quitting\\" or data == ''): 
       return 
      data_recieved(self.sock.recv(1000), self.sock) 

#################################################################################### 
server = False 
uname = str(input("What's your username: ")) 
print "Now for the technical stuff..." 
port = input("What port do I connect to ['any' if first]: ") 
if (port == "any"): 
    server = True 
    port = 9999 
    err = True 
    while err == True: 
     try: 
      sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
      sock.bind(('', port)) 
      err = False 
     except: 
      print "Socket #" + str(port) + " failed" 
      err = True 
      sock.close() 
      port -= 1 

    print "Bound to port #" + str(port) 
    print "Waiting for client..." 

    sock.listen(1) 
    (channel, info) = sock.accept() 
else: 
    host = input("What's the IP of the other client: ") 
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
    sock.connect((host, int(port))) 

if (server == True): 
    msg_loop(channel) 
else: 
    msg_loop(sock) 

reader.join() 
channel.send("\quitting\\") 
sock.close() 

正如你所看到的，我加了消息循環作爲回調。

另請注意，我發送空值，以規避「其他」問題。

那，我在data_recieved的打印結束處使用換行符來禁用換行符。

（如果你喜歡的代碼，它不運行，以及在Windows上，這是因爲，很顯然，在那裏Python的線程模型不作爲instentaniously執行。嘗試在您的本地Linux框）