How to pass multiple numbers from client to server and return their sum?

Question

Python

Hello!

Launched such a local server

import socket

sock = socket.socket()
sock.bind(('', 9090))
sock.listen(5)
connenction = sock.accept()
address = sock.accept()

print('connected:', addres)

while True:
    data = connect.recv(1024) #хватаю тестовое послание
   
   #a = connect.recv(1024)
   #b  = connect.recv(1024)
   #do = connectrecv(1024).encode() #неработающая часть, хочу посылать" a,b,действие" 
   #(тобишь посылаю "1,2,+" и на клиенте получаю 3 - но ничего не возвращает
    #data_1 = (a+b)
    #sock.send(data_1)
   
    if not data:
         print("пусто")
         break
    conn.send(data.upper())

conn.close()

//customer

import socket

sock = socket.socket()
sock.connect(('localhost', 9090))
sock.send("hello, world!".encode()) #тестовое послание

a = input("a= ")
sock.send(a.encode())
b = input("b= ")
sock.send(b.encode())

#do = input("+ - / *  ")
#sock.send(do.encode())
#do = "+".encode() не сработало
#sock.send(do)

data = sock.recv(1024)

sock.close()

print(data.decode())

Answer 1

Sketched on the knee.
Server:

import socket

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

server_address = ('localhost', 9090)
print('starting up on {} port {}'.format(*server_address))
sock.bind(server_address)

sock.listen(1)

while True:

    print('waiting for a connection')
    connection, client_address = sock.accept()
    try:
        print('connection from', client_address)

        while True:
            data = connection.recv(1024)
            print('received {!r}'.format(data))
            if data:
                print('sending data back to the client')
                input_data = (data.decode())
                expression = input_data[0] + input_data[2] + input_data[1]
                result = eval(expression)
                connection.sendall(str(result).encode())
            else:
                print('no data from', client_address)
                break

    finally:
        connection.close()

Customer:

import socket

sock = socket.socket()
sock.connect(('localhost', 9090))

a = input("a= ")
b = input("b= ")
do = input("+ - / *  ")

message = a + b + do
sock.send(message.encode())

data = sock.recv(1024)
res = data.decode()
print(res)

sock.close()