在Python中为TCP通信编码字符串时出现问题

Question

collective internet,

I am a very new programmer that has given myself a specific project to teach myself coding. I work with a lot of equipment that can take TCP commands so I set out to build a system of buttons that will send different commands per each button. I got myself a Raspberry Pi 3b and took online classes on Python. I've got reasonably far on my own (I've got the buttons working how I want!) but where I've been stuck is sending TCP commands.

To be more specific: I am sending data and it is being received but the string command is not being encoded properly. The commands are functional when I execute them in a telnet session, but obviously I want them executed as part of my script. The commands don't specify that they need to be received over a telnet session and, by other means, I've had these commands work as TCP commands exterior to a telnet session. I read about a telnet module for Python but I don't think I should need it.

I verified packet delivery with wireshark. I captured the packets sent by my script and the packets sent by the telnet session and they're similar but not the same. Horseshoes and hand grenades, right? My current method has been to just preface the string (within ') with a lower case b. I also tried putting .encode() after the string (omitting the b in that situation).

The string command has the format:

setInput "InputName" Value

So for my use case, I'm setting the input named "One" to a value of 1:

setInput "One" 1

So as you can see in my script (inserted below) I ended up using:

s.sendall(b'setInput "One" 1')

But it's not quite sending the right information because it is not working and it doesn't look the same in wireshark.

TL;DR: I'm trying to send packets via TCP but they're not being encoded properly.

Ultimately, my question is if I am even headed in the right direction using these commands and just need a different means to encode the string or if I need to explore another direction entirely (perhaps the telnet module?)

Here is the script I've been using to test and the wireshark output of my script:

import socket
import time

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(('192.168.100.40', 3040))
print('connected')
time.sleep(2)
s.sendall(b'setInput "One" 1')
print('sent increase')
time.sleep(2)
s.sendall(b'setInput "One" 0')
print('sent decrease')

Wireshark log of my script

Here is the wireshark output of the telnet session that was successful:

Wireshark log of the telnet session

Any and all help is appreciated. I looked far and wide and can't seem to find any cases similar to mine.

EDITS: Sorry for the poor formatting. I appreciate the advice on how better to present posts. This is my first post here and I'm just getting the hang of it. My photos are still links due to my lack of privileges here. Sorry if I was too wordy, I just wanted to supply as much information as possible so as to help people understand my problem and, if a solution is found, to help people with a similar issue find this.

Answer 1

The telnet tcp data includes a carriage return and a linefeed and the end of the data. Apparently the receiving part needs this to be included to make things work. So change your Python string to b'setInput "One" 1\\r\\n'