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Question

My question is regarding GUI programming in python by using tkinter. I believe this is Python 3x.

My question: While we're executing a program to run the GUI, can a button update a label? More specifically, is there a way to change the labels displayed text after pushing the button? I have consulted stack overflow on this before and adopted the StringVar() method, but it doesn't seem to fix my problem, in fact it omits the text from the GUI completely!

Here is the code below

from tkinter import *

root = Tk()
root.title('Copy Text GUI Program')

copiedtext = StringVar()
copiedtext.set("Text is displayed here")


def copytext():
    copiedtext.set(textentered.get())

# Write 'Enter Text Here'
entertextLabel = Label(root, text="Enter Text Here")
entertextLabel.grid(row=0, column=0)

# For the user to write text into the gui
textentered = Entry(root)
textentered.grid(row=0, column=1)

# The Copy Text Button
copytextButton = Button(root, text="Copy Text")
copytextButton.grid(row=1, columnspan=2)

# Display the copied text
displaytextLabel = Label(root, textvariable=copiedtext)
displaytextLabel.grid(row=2,columnspan=2)


copytextButton.configure(command=copytext())

root.mainloop()

Any help would be appreciated!

Answer 1

What you have to do is to bind a Button event to the copytextButton object like so:

copytextButton.bind('<Button-1>', copytext)

This means that a callback function - copytext() will be called when you left-click the button.

A slight modification is needed in the function itself, since the callback sends an event argument:

def copytext(event):
    copiedtext.set(textentered.get())

Edit: This line is not needed:

copytextButton.configure(command=copytext())