Non-blocking IO model to solve the blocking IO (socket example)

# Method: sk.setblocking (False) 

# server: 
Import Socket 
SK = socket.socket () 
sk.setblocking (False) 
sk.bind (( ' 127.0.0.1 ' , 8080 )) 
sk.listen () 
# define the empty for storing a list of individual Conn 
Conn_List = []
 # define removal list for the client to delete terminal disconnects Conn_List Conn 
Conn_Del = [] 

the while . 1 :
     the try : 
        Conn, addr = sk.accept () # If it is blocked IO, at this point the program will always be here waiting for 
        Conn_List.append (conn)   # overheard conn conn object into the list, namely multi-client connections 
    exceptBlockingIOError:
         '' ' If there is no client connected to try, the code block is executed, the client determines whether to transmit data to the server ' '' 
        # traversing conn list to see if there is no data sent by the client 
        for conn in Conn_List:
             try :
                 # attempt to receive data 
                info = conn.recv (1024) .decode ( ' UTF-. 8 ' )
                 # Note! If the client properly closed, that is, the client performs a close, the server receives an empty 
                IF  not info:
                     # If you receive an empty, prove the client disconnects, add the conn to delete the list for later deleted Conn_List corresponding Conn 
                    Conn_Del.append (Conn)
                     Print ( " the client has a disconnected ')
                     # Close the corresponding server in conn 
                    conn.Close ()
                 the else :
                     '' ' server logic level ' '' 
                    # If the client receives the data, the logic returns the data to the client layer 
                    Print ( ' which is received from the client } {data: {} ' .format (Conn, info))
                     # return data to the client (e.g., client lowercase to uppercase data back to the client) 
                    conn.send (info.upper () encode (. ' . 8-UTF ' ))
             the except BlockingIOError:
                 ' '' if the current cycle is not the transmission data conn, the code block is executed, i.e., the next communication conn '' ' 
                Continue 
            the exceptConnectionResetError:
                 '' ' If this cycle forced to withdraw from the conn, no action ' '' 
                Pass 
        # Delete to delete the list of customers Conn_List has been properly disconnected end conn 
        IF Conn_Del:
             for conn in Conn_Del: 
                Conn_List.remove (conn) 
            # after the finish to remove the normal close links clients should delete the list empty, otherwise it will error 
            Conn_Del = [] 
            
            
# clients: 
Import socket 
SK = socket.socket () 
sk.connect (( ' 127.0.0.1 ' , 8080 ))
 the while . 1 : 
    msg_s = INPUT ( ' >>> ')
    if not msg_s:continue
    if msg_s == 'q':break
    sk.send(msg_s.encode('utf-8'))
    print(sk.recv(1024).decode('utf-8'))
sk.close()