Redirect output from print function to Text and and disable it

Question

how can we redirect the output of the button action to TextBox in Tkinter? And after that TextBox should be grayed out. Here is the sample code I have written which prints the output on the console. I want "hello world" to be printed in the textbox and textbox should be grayed out. Any help would be appreciated.

from tkinter import *
import tkinter as tk

root = Tk()
root.geometry('700x650')
readOnlyText = tk.Text(root)

def testmethod():
    print("hello world-1")

textbox = Text(root,width=75,height=12)
textbox.place(x=60,y=100)

Button(root, text='Submit',command=testmethod,width=10,bg='brown',fg='white').place(x=300,y=350)

root.mainloop()

Answer 1

To intercept the print function, you will need to change the sys.stdout target. Refer to the example below

from tkinter import *
from io import StringIO
import sys

root = Tk()
root.geometry('700x650')

output=StringIO()
sys.stdout=output

def update():
    textbox['state']='normal'
    textbox.insert(END,output.getvalue())
    output.truncate(0)
    output.seek(0)
    textbox['state']='disabled'
    root.after(100,update)

def testmethod():
    print('Hello World')

textbox = Text(root,width=75,height=12)
textbox.place(x=60,y=100)

button=Button(root, text='Submit',command=testmethod,width=10,bg='brown',fg='white')
button.place(x=300,y=350)

update()

root.mainloop()

The update function will be called after every 100 milliseconds, which will insert the current value held by output and then clear it. The state of the Text widget should be normal to make any changes to its contents, hence the state has been toggled in every call.

To restore the output back to the shell, you can call

sys.stdout = sys.__stdout__