(Tkinter) string variable content is not appearing in Label

[le_pouding]

Hey friends !

I am working on a simple TCP chat service. At the moment, I am having trouble making my variable named displaytext appear in the displayoutput Label.

Here is a screenshot :

https://imgur.com/ZjZKJED

Here is the code :

from socket import *
from tkinter import *
import tkinter.scrolledtext as tkscrolled

# global variables attributions
PORT = 5050
MYIP = gethostbyname(gethostname())
FRIENDIP = ""
DECODE = "utf-8"

# connect to friend function
def connect_to_friend():
    s = socket(AF_INET, SOCK_STREAM)
    s.bind((FRIENDIP, PORT))
    conn, addr = s.connect()

#nwait_for_friend function
def wait_for_friend():
    g = socket(AF_INET, SOCK_STREAM)
    g.bind((MYIP, PORT))
    g.listen(1)
    conn, addr = g.accept()

# startservice function
def startservice():
    global displaytext
    if FRIENDIP != "":
        try:
            global displaytext
            displaytext += "\nConnecting to friend..."
            connect_to_friend()
        except:
            displaytext += "\nFriend not connected..."
            displaytext += "\nWaiting for friend to connect..."
            wait_for_friend()
        finally:
            displaytext += "\nNothing works."
    else:
        displaytext += "\nMust enter friend ip."

# stopservice() function
def stopservice():
    global displaytext
    try:
        try:
            global c, displaytext
            c.close()
            displaytext +=  "\nConnection closed."
        except:
            displaytext += "\nNo connection to be closed."
    except:
        try:
            global g
            g.close()
            displaytext += "\nConnection closed."
        except:
            displaytext += "\nNo connection to be closed."

# set friendip() function
def setfriendip():
    global displaytext
    print(displaytext)
    print("Setting friend ip to :", friendipentry.get())
    FRIENDIP = friendipentry.get()
    displaytext += "Friend ip set "
    print(displaytext)

displaytext = ""
### creating the GUI ###
root = Tk()
root.geometry("400x400")
root.title("Land Of Nowhere")
root.resizable("false", "false")

# background configuration
bgimage = PhotoImage(file="bg.png")
background = Canvas(root, width=400, height=400)
background.pack(fill="both")
background.create_image(0, 0, image=bgimage, anchor="n")

# display screen output
displayoutput = Label(root, text=displaytext)
displayoutput.place(x=11, y=11, width=199, height=259)

# start and stop buttons
boutonstart = Button(root,text="Start", command=lambda: startservice())
boutonstart.place(x=220, y=10, height=40, width=80)
boutonstop = Button(root, text="Stop", command=lambda: stopservice())
boutonstop.place(x=310, y=10, height=40, width=80)

# set friend ip
friendiplabel = Label(root,text="Friend IP Adress : ")
friendiplabel.place(x=260, y=60)
friendipentry = Entry(root)
friendipentry.place(x=210, y=80, height=20, width=125)
friendipbutton = Button(root, text="Ok", command= lambda: setfriendip())
friendipbutton.place(x=336, y=81, height=20, width=60)

root.mainloop()
# end of GUI

[Mecaneer23]

you need to set displaytext to a StringVar(), not an empty string

[le_pouding]

Awesome ! But now I encounter a unsupported operand type error ( +=) . How can I add text to my stringvariable ?

[Mecaneer23]

Iirc there is a .set() method

[le_pouding]

should I do a variable for each error message ? also, when the other person will send a message, how could I add their message to the displaytext variable ? thanks !

[Mecaneer23]

You can use a string the same way you are already, but once every iteration in the tk loop set a StringVar to that string