Develop Reference

Python how to use string in multiple scripts

I'm running a python script on a raspberry pi that reads keyboard input to a string and will be sending that string through TCP. I've made two script one that reads the input and one that can send the string if needed. How can i use one string and use it in both scripts for readings and writings?
I've used an text document. Only becaue of the sd card i wanne achieve an connecting between the two scripts
Reading part:
#loops for Barcode_Data
def Create_File():
file = open("Barcode_data.txt", "w")
file.write(" // ")
file.close()
empty = ''
def Barcode_Read():
Barcode_Data= input("Input: ",)
print(Barcode_Data)
file = open("Barcode_data.txt", "a")
file.write(Barcode_Data)
file.write(" // ")
file.close()
#Loop that will only run once
Create_File()
#Loop that will run continuesly
while True:
Barcode_Read()
TCP Server:
#TCP server
def TCP_Connect(socket):
socket.listen()
conn, addr = socket.accept()
with conn:
data = conn.recv(1024)
if data == b'Barcode_Data':
tcp_file = open("Barcode_data.txt", "r")
Barcode_Data = tcp_file.read()
tcp_file.close()
conn.sendall(Barcode_Data.encode('utf-8'))
elif data == b'Clear Barcode_Data':
tcp_file = open("Barcode_data.txt", "w")
tcp_file.write(" // ")
tcp_file.close()
#TCP Socket setup
HOST = '' # Standard loopback interface address (localhost)
PORT = 1025 # Port to listen on (non-privileged ports are > 1023)
import socket
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind((HOST, PORT))
#Loop that wil run continuesly
while True:
TCP_Connect(s)

You can use the code from this question as is: Interprocess communication in Python
Server process:
from multiprocessing.connection import Listener
address = ('localhost', 6000) # family is deduced to be 'AF_INET'
listener = Listener(address, authkey='secret password')
conn = listener.accept()
print 'connection accepted from', listener.last_accepted
while True:
msg = conn.recv()
# do something with msg
if msg == 'close':
conn.close()
break
listener.close()
Client process:
from multiprocessing.connection import Client
address = ('localhost', 6000)
conn = Client(address, authkey='secret password')
conn.send('close')
# can also send arbitrary objects:
# conn.send(['a', 2.5, None, int, sum])
conn.close()
Documentation is available here: https://docs.python.org/3.7/library/multiprocessing.html#multiprocessing-listeners-clients

how can we use both tcpSerSock.listen(0) and tcpSerSock.send(str.encode(message)) at the same time

my raspberry pi is the server and Im trying to send continuous message from rpi to android while recieving a command from client (android app),i really dont know if this is possible and how to do it is out of my reach and it is not a feedback message here is my code hope you will help me thank you.
import apptopi
from socket import *
from time import ctime
from nanpy import (ArduinoApi, SerialManager)
apptopi.setup()
connection = SerialManager()
a = ArduinoApi(connection = connection)
ctrCmd = ['Up','Down','Left','Right','Stop','Connect']
add = 0
add += 1
a = str(add) //**this is a sample that i want to send continously
HOST = ''
PORT = 21567
BUFSIZE = 1024
ADDR = (HOST,PORT)
tcpSerSock = socket(AF_INET, SOCK_STREAM)
tcpSerSock.bind(ADDR)
tcpSerSock.listen(0)
tcpSerSock.send(str.encode(a)) <== i really don't know how to send
continuously
while True:
print 'Waiting for connection'
tcpCliSock,addr = tcpSerSock.accept()
print '...connected from :', addr
try:
while True:
data = ''
data = tcpCliSock.recv(BUFSIZE)
if not data:
break
if data == ctrCmd[0]:
apptopi.forw()
print 'forward'
if data == ctrCmd[1]:
apptopi.back()
print 'backward'
if data == ctrCmd[2]:
apptopi.left()
print 'leftturn'
if data == ctrCmd[3]:
apptopi.right()
print 'rightturn'
if data == ctrCmd[4]:
apptopi.stp()
print 'stop'
except KeyboardInterrupt:
apptopi.close()
GPIO.cleanup()
tcpSerSock.close();

OK one approach is to use the select() function for this. There is information in the documentation about its operation.
As an example I've made a modified version of your program (see below). I don't have a raspberry pi, so that part of the code is commented out, but you can replace it as needed.
The example uses the timeout feature of select() to send "continuous" messages to clients whilst also monitoring them for incoming messages. You can adjust the message contents and timeout to whatever works for you. NB you may also need to respond to client messages, as this code only sends data to clients after a timeout. Make whatever changes you need.
import sys
import socket
import select
ctrCmd = ['Up','Down','Left','Right','Stop','Connect']
HOST = ''
PORT = 21567
BUFSIZE = 1024
ADDR = (HOST,PORT)
tcpSerSock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpSerSock.bind(ADDR)
tcpSerSock.listen(1)
print 'Waiting for connection'
sendInterval = 1.0 # interval(sec) for sending messages to connected clients
rxset = [tcpSerSock]
txset = []
while 1:
rxfds, txfds, exfds = select.select(rxset, txset, rxset, sendInterval)
if rxfds:
for sock in rxfds:
if sock is tcpSerSock:
# a client is connecting
tcpCliSock, addr = tcpSerSock.accept()
tcpCliSock.setblocking(0)
rxset.append(tcpCliSock)
print '...connected from :', addr
else:
# a client socket has data or has closed the connection
try:
data = sock.recv(BUFSIZE)
if not data:
print "...connection closed by remote end"
rxset.remove(sock)
sock.close()
else:
if data == ctrCmd[0]:
#apptopi.forw()
print 'forward'
if data == ctrCmd[1]:
#apptopi.back()
print 'backward'
if data == ctrCmd[2]:
#apptopi.left()
print 'leftturn'
if data == ctrCmd[3]:
#apptopi.right()
print 'rightturn'
if data == ctrCmd[4]:
#apptopi.stp()
print 'stop'
except:
print "...connection closed by remote end"
rxset.remove(sock)
sock.close()
else:
# timeout - send data to any active client
for sock in rxset:
if sock is not tcpSerSock:
sock.send("Hello!\n")
The simple client program I used to test this is here:
import sys
import socket
import time
ctrCmd = ['Up','Down','Left','Right','Stop','Connect']
HOST = '127.0.0.1'
PORT = 21567
BUFSIZE = 1024
ADDR = (HOST,PORT)
tcpCliSock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpCliSock.connect(ADDR)
time.sleep(1)
for i in range(len(ctrCmd)):
tcpCliSock.send(ctrCmd[i])
time.sleep(1)
data = tcpCliSock.recv(BUFSIZE)
print data
tcpCliSock.close()
Hope this helps, best of luck.

Send a message to multiple hosts with python socket.

first of all i want to clarify. I don't have any deep knowledge on python, but im trying to learn while doing a project for college so lets start and thanks for your time.
I'm working with Python 3.4 on Windows 10 for the hosts and Ubuntu in an Odroid as a server.
The problem on my code is that i need to send a code like 0001 to a set of hosts of which i have their ips but when i try to close the socket it won't do it and i can't open a new one to send the code to the next host.
Client code :
[yes, it's a socket server code but when i try to connect multiple clients to one server, the code stopped on listening new connections and i couldn't "fix" it in another way]
while 1:
TCP_PORT = 5000
BUFFER_SIZE = 4 # Normally 1024, but we want fast response
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(('', TCP_PORT))
s.listen(1)
s, addr = s.accept()
data = s.recv(BUFFER_SIZE)
if not data:
break
if data.decode('ascii') == '0001':
print (data.decode('ascii'))
s.shutdown(socket.SHUT_RDWR)
s.close()
Server side code:
import serial
import time
import mysql.connector
import shutil
import socket
import sys
import _thread
joined_seq = '0001'
Alerta = True
TotalClientes = True
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
seq = []
UltimaIPextraida = ''
port = 5000
while Alerta == True:
if TotalClientes == True:
cnx2 = mysql.connector.connect(connection parameters removed)
cursor2 = cnx2.cursor()
cursor2.execute("SELECT MAX(Entrada) FROM Host")
for (Entrada) in cursor2:
NoTupla = ''.join(str(v) for v in Entrada)
ValorMAX = int(NoTupla)
cursor2.close()
cnx2.close()
TotalClientes = False
if ValorMAX > 0:
print('Host Numero', ValorMAX)
cnx3 = mysql.connector.connect(connection parameters removed)
cursor3 = cnx3.cursor()
query = ("SELECT IP FROM Host WHERE entrada = '%s' " % (ValorMAX))
cursor3.execute(query)
for (IP) in cursor3:
IPextraida = ''.join(str(v) for v in IP)
cursor3.close()
cnx3.close()
#if ValorMAX == 1: #DESCOMENTAR
# Alerta = False #DESCOMENTAR
ValorMAX = ValorMAX -1
print('IP Extraida = ' + IPextraida)
print('Ultima IP Extraida = '+ UltimaIPextraida)
if UltimaIPextraida == IPextraida:
print('Ultima IP extraida es identica a la nueva ip extraida, pasando a la siguiente')
elif UltimaIPextraida != IPextraida:
try:
s.connect((IPextraida, port))
s.send(joined_seq.encode('ascii'))
s.shutdown(s.SHUT_RDWR)
s.close()
print('Mensaje enviado correctamente = ' + joined_seq)
except:
print('No se pudo conectar con host')
UltimaIPextraida = IPextraida
** some code was ommited because it has no relevance **
With the mysql query i get the total of ip entries on the table and then with that i get all ip one by one to make the socket connection.
I really hope someone can help me to solve this problem... i've been 2 days trying and i'm running out of time to finish the code and it isn't the main part of the project, i only need a functional code to show some capabilities of the arduino functions graphically.
thank you all for your time and sorry for the gramatical errors and the code in spanish :(

Solved with this:
def enviaMensaje(ipdelwn):
enviado=False
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
try:
s.connect((ipdelwn, port))
s.send(joined_seq.encode('ascii'))
s.close()
print('Mensaje enviado correctamente = ' + joined_seq)
enviado=True
except:
print('No se pudo conectar con host')
return enviado

Server that echos the client number?

Trying to make a server that tells the client what number he/she is. For example, once you connect it should say something like "Welcome client #5" or something along those lines. Right now I'm just trying to write it so that it simply reads a line in and echos it back. Im stuck on as far as getting it to show the clients number.
import socket
import sys
host = ''
port = 37373
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host,port))
s.listen(1)
while 1:
s, address = s.accept()
data = s.recv(1024)
if data:
s.send(data)
s.close()

that is
import socket
import sys
Clinet_number = 0
host = ''
port = 37373
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host,port))
s.listen(10) # number of queued connections
while 1:
Client_number += 1
s, address = s.accept()
data = s.recv(1024)
if data:
s.send(str(Client_number))
s.close()

Receive more than one message on more than one port Echo Server python

I am writing a echo server and client in Python, that implements a simple number guessing game. I know how to multiplex using select, that's fine. The other server I wrote achieves this. But now I am writing a new server (which is fairly similar), however it accepts connections from two ports rather than one, one port for player client, and one for admin which I will use eventually for the who command, returning all connected players.
My problem is, that after sending the initial greetings message, the clients receive feedback from the server on the first send, recv. But after that I cannot send any more messages to server (nothing gets sent from the clients), I have been searching and playing around for hours, to no avail. Any help would be appreciated. Thanks!
# MULTIPLEX SERVER
import socket, select, time, random, ssl, sys, os
# VARS
EXP = 1
HOST = '127.0.0.1'
PORT_P = 4000
PORT_A = 4001
BUFFSZ = 1024
BKLOG = 5
GREETS = 'Greetings'
INPUTS = []
OUTPUTS = []
CLIENT_ADDRS = {}
CLIENT_ANS = {}
CLIENTS = ""
_adm_rtnMSG = 'Admin_Greetings'
# Function to determine how far the player is
# from the chosen random number
def Within(value, target):
diff = abs(target - value)
if diff > 3:
return 'Not even close, youth!'
else:
return 'Ooh, not to far: ' + str(diff) + ' away, keep trying...'
# END_FUNCTION
print('Server up and running...\n')
try:
for p in PORT_P, PORT_A:
INPUTS.append(socket.socket(socket.AF_INET, socket.SOCK_STREAM))
INPUTS[-1].setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
INPUTS[-1].bind((HOST, p))
INPUTS[-1].listen(BKLOG)
except socket.error(value, message):
if INPUTS[-1]:
INPUTS[-1].close()
INPUTS = INPUTS[:-1]
print('Failure to open socket: ' + message)
sys.exit(1)
while True:
READ_IO, WRITE_IO, ERROR = select.select(INPUTS, OUTPUTS, INPUTS)
for r in READ_IO:
for p in INPUTS:
if r is p:
(acpt_sock, addr) = p.accept()
print('Connection established with ', acpt_sock.getsockname())
CLIENT_ADDRS[acpt_sock] = addr
CLIENT_ANS[acpt_sock] = random.randrange(1, 20)
else:
data = acpt_sock.recv(BUFFSZ).decode()
acpt_sock.setblocking(0)
if data:
if 'Hello' in data:
print(CLIENT_ADDRS[acpt_sock], ' random number is: ', CLIENT_ANS[acpt_sock])
acpt_sock.send(b'Greetings\nGuess a random number between 1 & 20')
# drop elif here for admin cmd
elif 'Hi' in data:
acpt_sock.send(_adm_rtnMSG.encode())
else:
if int(data) == CLIENT_ANS[acpt_sock]:
acpt_sock.send(b'That was correct, Well done!')
else:
acpt_sock.send(str(Within(int(data), CLIENT_ANS[acpt_sock])).encode())
else:
print('Closing Connection # ', addr)
INPUTS.remove(acpt_sock)
acpt_sock.close()
del CLIENT_ADDRS[acpt_sock]
# PLAYER CLIENT
import socket
import re
# INIT VARS
HOST = '127.0.0.1'
PORT = 4000
INITSTR = 'Hello'
BUFF = 1024
# Set up socket
sender = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sender.connect((HOST, PORT))
sender.send(bytes((INITSTR), "ascii"))
print("Kirby Prompt FTW!\nConnected to Server via", HOST, "::", PORT, '\n')
rtnMSG = sender.recv(BUFF).decode()
print(rtnMSG)
# Simple loop to keep client alive
# to send and receive data from the server
while 'correct' not in rtnMSG:
_guess = input("(>',')> ")
sender.send(bytes((_guess), "ascii"))
rtnMSG = sender.recv(BUFF).decode()
print(rtnMSG)
sender.close()
# ADMIN CLIENT
import socket
import re
import ssl
# INIT VARS
HOST = '127.0.0.1'
PORT = 4001
INITSTR = 'Hi'
BUFF = 1024
# Set up socket
adm_sender = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
adm_sender.connect((HOST, PORT))
adm_sender.send(bytes((INITSTR), "ascii"))
print("Connected to Server as Admin via", HOST, "::", PORT, '\n')
rtnMSG = adm_sender.recv(BUFF).decode()
print(rtnMSG)
while True:
cmd = input('$ ')
adm_sender.send(bytes((cmd), "ascii"))
rtnMSG = adm_sender.recv(BUFF).decode()
print(rtnMSG)
adm_sender.close()