Tkinter threading for socket receiving data - multithreading

Question

im working on a project for my networking class which is a client to interact with a server which hosts a text based game written by our professor.
I have almost everything figured out but i have one major issue, I don't know python very well and threading has been difficult to implement to continuously receiving data from the server.
RuntimeError: main thread is not in main loop
this is the error that i am getting, i believe it is because tkinter must be in the main thread always and its conflicting with my receiving function. I have seen that a Queue might be the soulution to this issue but i am having trouble understanding how to implement this into my code, any help would be great thanks.
from tkinter import *
import tkinter.simpledialog
from sys import exit
from struct import *
from socket import *
import threading
import tkinter.scrolledtext as tkst
skt = socket(AF_INET, SOCK_STREAM)
skt.connect(("domainname.com", 5191))
root = Tk()
def main():
thread = threading.Thread(target = recieve)
thread.start()
thread.join()
root.mainloop()
def start_func():
m = 6
def create_func():
m = 10
def change_func():
m = 2
print(m)
def fight_func():
m = 3
print(m)
def pvp_func():
m = 4
print(m)
def loot_func():
m = 5
skt.send(m)
print(m)
def leave_func():
m = 12
print(m)
def submit_value():
global userEntry
length = len(userEntry.get())
e1.delete(0, END)
class TestClient(Frame):
def __init__(self, master):
global userEntry
Frame.__init__(self, master)
self.pack()
for n in range(3):
self.grid_rowconfigure(n, weight=1)
for n in range(8):
self.grid_columnconfigure(n, weight=1)
self.Messg_text = tkst.ScrolledText(self,wrap = WORD, width=80)
self.Messg_text.grid(row=0, column=0, columnspan=8)
la1 = Label(self, text="Value entry:")
la1.grid(row=1, column=0)
userEntry = StringVar()
global e1
e1 = Entry(self, width=40, textvariable=userEntry)
e1.grid(row=1, column=1, columnspan=6)
e2 = Button(self, text="Enter", command=submit_value)
e1.delete(0, END)
e2.grid(row=1, column=5, columnspan=10)
b1 = Button(self, text="Start", width=10,padx=10,pady=10, command=start_func)
b1.grid(row=2, column=0)
b0 = Button(self, text="Create Character", width=10,padx=10,pady=10, command=create_func)
b0.grid(row=2, column=1)
b2 = Button(self, text="Change Room", width=10,padx=10,pady=10, command=change_func)
b2.grid(row=2, column=3)
b3 = Button(self, text="FIGHT", width=10,padx=10,pady=10, command=fight_func)
b3.grid(row=2, column=4)
b4 = Button(self, text="PvP FIGHT", width=10,padx=10,pady=10, command=pvp_func)
b4.grid(row=2, column=5)
b5 = Button(self, text="Loot", width=10,padx=10,pady=10, command=loot_func)
b5.grid(row=2, column=6)
b6 = Button(self, text="Leave", width=10,padx=10,pady=10, command=leave_func)
b6.grid(row=2, column=7)
tw = TestClient(root)
def recieve():
while(True):
mesg_type = skt.recv(1)
if(mesg_type == b'\x01'):
msg_Len = skt.recv(2)
msg_int_Len = struct.unpack('h',msg_Len)
Recip_Name = skt.recv(32)
sender_Name = skt.recv(32)
mesg = skt.recv(msg_int_Len)
PostMessage(Recip_Name,sender_Name,mesg)
elif(mesg_type == b'\x0b'):
init_Points = skt.recv(2)
statLim = skt.recv(2)
descriptLen = skt.recv(2)
descriptLen = unpack('h',descriptLen)
gameDiscript = skt.recv(descriptLen[0])
print(gameDiscript.decode("utf-8"))
Post11Message(str(gameDiscript)[0:-2])
def PostMessage(name, senderName, Message):
tw.Messg_text.insert(INSERT,Message)
def Post11Message(gameDiscript):
tw.Messg_text.insert(INSERT,gameDiscript)
main()

Answer 1

I'm fairly sure the reason why you are having an issue is because thread.join waits until the thread is finished before doing whatever is next. So, in your case, you are never actually calling root.mainloop(). The solution would just be to take out the thread.join line in main.
Also, in your case, a queue is necessary because you can't change a Tkinter widget in another thread.
Without too much editing, here's what your code would look like.
from tkinter import *
import tkinter.simpledialog
from sys import exit
from struct import *
from socket import *
import Queue
import threading
import tkinter.scrolledtext as tkst
skt = socket(AF_INET, SOCK_STREAM)
skt.connect(("domainname.com", 5191))
root = Tk()
def main():
thread = threading.Thread(target = recieve)
thread.start()
root.mainloop()
def start_func():
m = 6
def create_func():
m = 10
def change_func():
m = 2
print(m)
def fight_func():
m = 3
print(m)
def pvp_func():
m = 4
print(m)
def loot_func():
m = 5
skt.send(m)
print(m)
def leave_func():
m = 12
print(m)
def submit_value():
global userEntry
length = len(userEntry.get())
e1.delete(0, END)
class TestClient(Frame):
def __init__(self, master):
global userEntry
Frame.__init__(self, master)
self.pack()
for n in range(3):
self.grid_rowconfigure(n, weight=1)
for n in range(8):
self.grid_columnconfigure(n, weight=1)
self.Messg_text = tkst.ScrolledText(self,wrap = WORD, width=80)
self.Messg_text.grid(row=0, column=0, columnspan=8)
la1 = Label(self, text="Value entry:")
la1.grid(row=1, column=0)
userEntry = StringVar()
global e1
e1 = Entry(self, width=40, textvariable=userEntry)
e1.grid(row=1, column=1, columnspan=6)
e2 = Button(self, text="Enter", command=submit_value)
e1.delete(0, END)
e2.grid(row=1, column=5, columnspan=10)
b1 = Button(self, text="Start", width=10,padx=10,pady=10, command=start_func)
b1.grid(row=2, column=0)
b0 = Button(self, text="Create Character", width=10,padx=10,pady=10, command=create_func)
b0.grid(row=2, column=1)
b2 = Button(self, text="Change Room", width=10,padx=10,pady=10, command=change_func)
b2.grid(row=2, column=3)
b3 = Button(self, text="FIGHT", width=10,padx=10,pady=10, command=fight_func)
b3.grid(row=2, column=4)
b4 = Button(self, text="PvP FIGHT", width=10,padx=10,pady=10, command=pvp_func)
b4.grid(row=2, column=5)
b5 = Button(self, text="Loot", width=10,padx=10,pady=10, command=loot_func)
b5.grid(row=2, column=6)
b6 = Button(self, text="Leave", width=10,padx=10,pady=10, command=leave_func)
b6.grid(row=2, column=7)
#Data Queue
self.queue = Queue.Queue()
self.queue_check()
def queue_check(self):
try:
#Inserts Data
text = self.queue.get_nowait(0)
self.Messg_text.insert(INSERT, text)
#If Nothing In Queue
except Queue.Empty:
#Repeats Itself After 100 ms
self.after(100, self.queue_check)
tw = TestClient(root)
def recieve():
while(True):
mesg_type = skt.recv(1)
if(mesg_type == b'\x01'):
msg_Len = skt.recv(2)
msg_int_Len = struct.unpack('h',msg_Len)
Recip_Name = skt.recv(32)
sender_Name = skt.recv(32)
mesg = skt.recv(msg_int_Len)
PostMessage(Recip_Name,sender_Name,mesg)
elif(mesg_type == b'\x0b'):
init_Points = skt.recv(2)
statLim = skt.recv(2)
descriptLen = skt.recv(2)
descriptLen = unpack('h',descriptLen)
gameDiscript = skt.recv(descriptLen[0])
print(gameDiscript.decode("utf-8"))
Post11Message(str(gameDiscript)[0:-2])
def PostMessage(name, senderName, Message):
#Adds Message To Queue
tw.queue.put(Message)
def Post11Message(gameDiscript):
#Adds gameDiscript to Queue
tw.queue.put(gameDiscript)
main()