Hello I want some help figuring out how to change the text of a tk.label that is in a subframe

here is the code.

from time import sleep                # Imported the sleep funtion from time for delays
from tkinter import *                 # Imported all of the tkinter functions associated with creating the GUI
from tkinter.ttk import Progressbar
from threading import Thread        
import tkinter as tk
#import pyvisa
from serial import*
from tkinter import ttk
from PIL import ImageTk, Image
import threading


#####################################################################################
########################## Quick adjustments ########################################

MainTitleTextSize = 24
GeneralTitleTextSize = 20
GeneralTextSize = 18
LabelTextFont = "Geia"
ButtonTextFont = "Geia Bold"
Backgroundcolor = "Black"
Bordercolor = "cyan"
BorderThickness = 4
ProgramSelectedTextcolor = "green"
FroundFramecolor = "#8ad9ff"              
FroundLabelcolor = "#8ad9ff"              
FroundButtoncolor = "#8ad9ff"             
Labelcolor1 = "green2"
Labelcolor2 = "#8ad9ff" 
DrManhatanBlue = "#8ad9ff" 

DarkMode = "#1e1e1e"            
DrManhatanBlue = "#8ad9ff"       
root=tk.Tk()                     # Instantiates a Tk object
root.title("Tester")             
root.configure(bg=DarkMode)     
root.geometry('1000x800')

OPCUA_Var          = tk.StringVar()
#####################################################################################
########################## OPCUA Window Popup #######################################

# function to open a new window 
# on a button click
def open_OPCUA_Window():
     
    # Toplevel object which will 
    # be treated as a new window
    OPCUAWindow = tk.Toplevel(root)
    OPCUAWindow.title("OPCUA Configuration")
    OPCUAWindow.configure(bg=DarkMode)      # Changes the background to this color
    OPCUAWindow.geometry("600x400")
    # A Label widget to show in toplevel
    OPCFrame                = tk.LabelFrame(OPCUAWindow, text="", padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 18))
    OPCLabel                = tk.Label(OPCFrame,  text="  OPCUA Settings "   , padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 18))
    OPCcommand_label        = tk.Label(OPCFrame, text =" Manual Command   :", bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 12))
    OPCcommand_entry        = tk.Entry(OPCFrame,textvariable = OPCUA_Var, font=('calibre',12,'normal'))
    OPCsub_btn              = tk.Button(OPCFrame,text = 'Submit',padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 12), command = OPCsubmit)
    OPCReturn               = tk.Label(OPCFrame, text =" return   :", bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 12))
    
    OPCFrame.grid(             row=0, column=0, sticky="w")
    OPCLabel.grid(             row=0, column=0, sticky="w")
    OPCcommand_label.grid(     row=1, column=0, sticky="w")
    OPCcommand_entry.grid(     row=1, column=1, sticky="E")
    OPCsub_btn.grid(           row=1, column=2, sticky="w")
    OPCReturn.grid(            row=2, column=0, sticky="E")
                            
#####################################################################################
########### Manual input functions for OPC Configuration Window ##################

def OPCUA_COMMAND(OPCcommand):

    passthrough = OPCcommand

  
    Datapopup.config(text = passthrough)  
    OPCReturn.config(text = passthrough) 

    

   



def OPCsubmit():
 
    opccommand=OPCUA_Var.get()

     
    print("The command sent was:" + opccommand)

    OPCUA_COMMAND(opccommand)
     
    OPCUA_Var.set("")
 

##############################################################################
###########################Navigation frame###################################

NavigationFrame          = tk.LabelFrame(root, text="", padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 18))
NavigationLabel          = tk.Label(NavigationFrame, text="    Navigation      "  , bg=DarkMode, fg=DrManhatanBlue, font=("Geia", 12))

NavigationButton3        = tk.Button(NavigationFrame, text=" OPCUA Configuration  "  , bg=DrManhatanBlue, fg="black", font=("Geia", 12),command = open_OPCUA_Window)
    

NavigationFrame.grid(      row=5,padx=10,pady=0, sticky="we", columnspan=10,rowspan=2)
NavigationLabel.grid(      row=0, columnspan=6, sticky="w",rowspan=2)
NavigationButton3.grid(    row=1, column = 2, sticky="w",rowspan=2)

##############################################################################
###########################Data frame#########################################

DataFrame          = tk.LabelFrame(root, text="", padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 18))
DataLabel          = tk.Label(DataFrame, text="Data            : "  , bg=DarkMode, fg=DrManhatanBlue, font=("Geia", 12))
Datapopup          = tk.Label(DataFrame, text="            "  , bg=DarkMode, fg=DrManhatanBlue, font=("Geia", 12))

DataFrame.grid(      row=3,padx=10,pady=0, sticky="we", columnspan=6,rowspan=2)
DataLabel.grid(      row=0, column = 1, sticky="w",rowspan=2)
Datapopup.grid(      row=0, column = 2, sticky="w",rowspan=2, columnspan=5,)


root.mainloop()

You can see that I am cable to configure the text in the "data frame" window but when I try to change the text in the "opcua window pop up"
I get a NameError: name 'OPCReturn' is not defined when I try to run OPCReturn.config(text = passthrough)

Hello I want some help figuring out how to change the text of a tk.label that is in a subframe

here is the code.

from time import sleep                # Imported the sleep funtion from time for delays
from tkinter import *                 # Imported all of the tkinter functions associated with creating the GUI
from tkinter.ttk import Progressbar
from threading import Thread        
import tkinter as tk
#import pyvisa
from serial import*
from tkinter import ttk
from PIL import ImageTk, Image
import threading


#####################################################################################
########################## Quick adjustments ########################################

MainTitleTextSize = 24
GeneralTitleTextSize = 20
GeneralTextSize = 18
LabelTextFont = "Geia"
ButtonTextFont = "Geia Bold"
Backgroundcolor = "Black"
Bordercolor = "cyan"
BorderThickness = 4
ProgramSelectedTextcolor = "green"
FroundFramecolor = "#8ad9ff"              
FroundLabelcolor = "#8ad9ff"              
FroundButtoncolor = "#8ad9ff"             
Labelcolor1 = "green2"
Labelcolor2 = "#8ad9ff" 
DrManhatanBlue = "#8ad9ff" 

DarkMode = "#1e1e1e"            
DrManhatanBlue = "#8ad9ff"       
root=tk.Tk()                     # Instantiates a Tk object
root.title("Tester")             
root.configure(bg=DarkMode)     
root.geometry('1000x800')

OPCUA_Var          = tk.StringVar()
#####################################################################################
########################## OPCUA Window Popup #######################################

# function to open a new window 
# on a button click
def open_OPCUA_Window():
     
    # Toplevel object which will 
    # be treated as a new window
    OPCUAWindow = tk.Toplevel(root)
    OPCUAWindow.title("OPCUA Configuration")
    OPCUAWindow.configure(bg=DarkMode)      # Changes the background to this color
    OPCUAWindow.geometry("600x400")
    # A Label widget to show in toplevel
    OPCFrame                = tk.LabelFrame(OPCUAWindow, text="", padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 18))
    OPCLabel                = tk.Label(OPCFrame,  text="  OPCUA Settings "   , padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 18))
    OPCcommand_label        = tk.Label(OPCFrame, text =" Manual Command   :", bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 12))
    OPCcommand_entry        = tk.Entry(OPCFrame,textvariable = OPCUA_Var, font=('calibre',12,'normal'))
    OPCsub_btn              = tk.Button(OPCFrame,text = 'Submit',padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 12), command = OPCsubmit)
    OPCReturn               = tk.Label(OPCFrame, text =" return   :", bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 12))
    
    OPCFrame.grid(             row=0, column=0, sticky="w")
    OPCLabel.grid(             row=0, column=0, sticky="w")
    OPCcommand_label.grid(     row=1, column=0, sticky="w")
    OPCcommand_entry.grid(     row=1, column=1, sticky="E")
    OPCsub_btn.grid(           row=1, column=2, sticky="w")
    OPCReturn.grid(            row=2, column=0, sticky="E")
                            
#####################################################################################
########### Manual input functions for OPC Configuration Window ##################

def OPCUA_COMMAND(OPCcommand):

    passthrough = OPCcommand

  
    Datapopup.config(text = passthrough)  
    OPCReturn.config(text = passthrough) 

    

   



def OPCsubmit():
 
    opccommand=OPCUA_Var.get()

     
    print("The command sent was:" + opccommand)

    OPCUA_COMMAND(opccommand)
     
    OPCUA_Var.set("")
 

##############################################################################
###########################Navigation frame###################################

NavigationFrame          = tk.LabelFrame(root, text="", padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 18))
NavigationLabel          = tk.Label(NavigationFrame, text="    Navigation      "  , bg=DarkMode, fg=DrManhatanBlue, font=("Geia", 12))

NavigationButton3        = tk.Button(NavigationFrame, text=" OPCUA Configuration  "  , bg=DrManhatanBlue, fg="black", font=("Geia", 12),command = open_OPCUA_Window)
    

NavigationFrame.grid(      row=5,padx=10,pady=0, sticky="we", columnspan=10,rowspan=2)
NavigationLabel.grid(      row=0, columnspan=6, sticky="w",rowspan=2)
NavigationButton3.grid(    row=1, column = 2, sticky="w",rowspan=2)

##############################################################################
###########################Data frame#########################################

DataFrame          = tk.LabelFrame(root, text="", padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor , font=(LabelTextFont, 18))
DataLabel          = tk.Label(DataFrame, text="Data            : "  , bg=DarkMode, fg=DrManhatanBlue, font=("Geia", 12))
Datapopup          = tk.Label(DataFrame, text="            "  , bg=DarkMode, fg=DrManhatanBlue, font=("Geia", 12))

DataFrame.grid(      row=3,padx=10,pady=0, sticky="we", columnspan=6,rowspan=2)
DataLabel.grid(      row=0, column = 1, sticky="w",rowspan=2)
Datapopup.grid(      row=0, column = 2, sticky="w",rowspan=2, columnspan=5,)


root.mainloop()

You can see that I am cable to configure the text in the "data frame" window but when I try to change the text in the "opcua window pop up"
I get a NameError: name 'OPCReturn' is not defined when I try to run OPCReturn.config(text = passthrough)

• python
• tkinter

Share Improve this question Follow asked Mar 20 at 15:17 Kyle RKyle R 922 bronze badges 1

• 1 I'd be careful using sleep anywhere in the main thread, as your GUI will hang for as long as it's sleeping. I'd also recommend taking a look at the Python style guide - writing Python with a conventional style makes it easier for you and other devs to work on and understand. – JRiggles Commented Mar 20 at 15:29

Add a comment  | 

1 Answer 1

Sorted by: Reset to default 1

The NameError: name 'OPCReturn' is not defined occurs because the OPCReturn label is defined inside the open_OPCUA_Window function, making it a local variable. To fix this, you need to make OPCReturn accessible to other functions by declaring it as a global variable.

Here's how you can fix it:

1. Declare OPCReturn as a global variable inside the open_OPCUA_Window function.

2. Ensure that OPCReturn is referenced correctly in the OPCUA_COMMAND function.

Here's the updated code:

def open_OPCUA_Window():
    global OPCReturn  # Declare OPCReturn as global
    OPCUAWindow = tk.Toplevel(root)
    OPCUAWindow.title("OPCUA Configuration")
    OPCUAWindow.configure(bg=DarkMode)
    OPCUAWindow.geometry("600x400")
    
    OPCFrame = tk.LabelFrame(OPCUAWindow, text="", padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor, font=(LabelTextFont, 18))
    OPCLabel = tk.Label(OPCFrame, text="  OPCUA Settings ", padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor, font=(LabelTextFont, 18))
    OPCcommand_label = tk.Label(OPCFrame, text=" Manual Command   :", bg=DarkMode, fg=FroundFramecolor, font=(LabelTextFont, 12))
    OPCcommand_entry = tk.Entry(OPCFrame, textvariable=OPCUA_Var, font=('calibre', 12, 'normal'))
    OPCsub_btn = tk.Button(OPCFrame, text='Submit', padx=5, pady=5, bg=DarkMode, fg=FroundFramecolor, font=(LabelTextFont, 12), command=OPCsubmit)
    OPCReturn = tk.Label(OPCFrame, text=" return   :", bg=DarkMode, fg=FroundFramecolor, font=(LabelTextFont, 12))
    
    OPCFrame.grid(row=0, column=0, sticky="w")
    OPCLabel.grid(row=0, column=0, sticky="w")
    OPCcommand_label.grid(row=1, column=0, sticky="w")
    OPCcommand_entry.grid(row=1, column=1, sticky="E")
    OPCsub_btn.grid(row=1, column=2, sticky="w")
    OPCReturn.grid(row=2, column=0, sticky="E")

def OPCUA_COMMAND(OPCcommand):
    passthrough = OPCcommand
    Datapopup.config(text=passthrough)
    OPCReturn.config(text=passthrough)  # This will now work correctly

def OPCsubmit():
    opccommand = OPCUA_Var.get()
    print("The command sent was:" + opccommand)
    OPCUA_COMMAND(opccommand)
    OPCUA_Var.set("")

By declaring OPCReturn as a global variable, it becomes accessible to the OPCUA_COMMAND function, allowing you to update its text without encountering a NameError.