Receiving data with sockets adding characters - sockets

Question

I'm writing a mod for a game to allow me to use a second screen with a set of stats. Now I send the data and receive, however there's extra characters when I receive the data, such as , ' ). This is causing issue's preventing me to create an int variable. I've tried stripping these characters but still having problems. This is the error spat out: ValueError: invalid literal for int(*) with base 10: "(0'"
Here's what i'm sending:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = '192.168.0.2'
port = 9000
s.bind((host,port))
s.listen(5)
conn, addr = s.accept()
print ('Got connection from', addr)
while True:
#--- RPM --
rpm = info.physics.rpms
max_rpm = info.static.maxRpm
if rpm != 0:
rpm_percent = int(rpm/max_rpm*100)
else:
rpm_percent = 0
#--- SPEED ---
speed = int(info.physics.speedKmh/1.609344)
#--- GEAR ---
gear = info.physics.gear - 1
if gear == 0:
gear = str("N")
elif gear < 0:
gear = str("R")
#--- FUEL ---
fuel = info.physics.fuel
max_fuel = info.static.maxFuel
if fuel != 0:
fuel_percent = int(fuel/max_fuel*100)
else:
fuel_percent = 0
#--- BRAKING ---
brake = info.physics.brake
braking_lvl = int(brake/100*10000)
#--- LAP ---
current_time = info.graphics.currentTime
#--- SEND DATA ---
time.sleep(.1)
#print_data = 'Speed: ', speed, 'RPM: ', rpm_percent, 'Gear: ', gear, 'Braking: ', braking_lvl, 'Fuel: ', fuel, fuel_percent,'Lap Time: ', current_time
send_data = (speed, ';', rpm, ';', rpm_percent, ';', gear, ';', braking_lvl, ';', fuel, ';', fuel_percent)
conn.send(str(send_data).encode('ascii'))
print(send_data)
s.close()
And on the client, which has the errors:
data = s.recv(1024).decode('ascii').replace(' ', '').replace("'", '').replace(')', '').replace(',', '')
data = data.split(';')
speed = int(data[0])
rpm = int(data[1])
rpm_percentage = int(data[2])
gear = str(data[3])
breaking_lvl = int(data[4])
fuel = int(data[5])
fuel_percentage= int(data[6])
Why is it seeing these extra characters? And what's the most effective method to remove them / prevent them?
Cheers.

Answer 1

send_data is a tuple. If you call str(); it returns its string representation '(item, item)'. To read it back you would need eval() or ast.literal_eval() (in simple cases). You could use json format instead.
On the server:
sock.sendall(json.dumps(data).encode('utf-8'))
On the client (assuming the connection is closed after receiving the response from the server):
response = []
while True:
chunk = sock.recv(1024)
if not chunk: # EOF
break
response.append(chunk)
data = json.loads(b"".join(response).decode('utf-8'))

Answer 2

You need to check how much data you receive, and ensure that the string is null terminated at the end of the data that was received, otherwise you will be parsing random data.
For reliability, you should send a fixed length message that tells the client how much data to expect. Then the client can ensure that it receives all the data sent, and no more.