Python Forum

Hello
At the beginning I want show you what I want achieve.
I using tkinter: 2 text field and 1 button:
in the first text field I enter:
one
two
three
I press the button
The second field should show:
a:one
a:two
a:three
but unfortunately it appears:
a:one
two
three

it is my code:

import tkinter as tk
from tkinter import *

def OpenWindow():
    root = tk.Tk()
    root.geometry('400x250')
    return root

root = OpenWindow()

text1 = Text(root, width='12', height='10')
text1.place(x=20,y=20)


text2 = Text(root, width="12", height="10")
text2.place(x=240,y=20)

def click(): 
    text_input = text1.get("1.0", END)
    text2.delete(1.0, END)

    for i in text_input:
        row_word = ('a:' + text_input)

    text2.insert(1.0, row_word)
  
button_click = Button(root, text='add', command=click)
button_click.pack()

root.mainloop()

Thank you for help, I beginning my adventure with Python so maybe my question is tryvial...

Your problem is test_input is one string, not three strings. Your function will have to split test_input into three strings, prepend "a:" to each string, and put the strings back together.

You can use str.split() for this if you know the delimiter and the delimiter is only used to separate words in the string. This is an example where words are separated by a space.

words = ('one two three').split(' ')  # Split string into words separated by a space
row_words = [f'a:{word}' for word in words]  # Prepend a: to each word
print(' '.join(row_words))  # Join the words together separated by a space

Output:
a:one a:two a:three

I think you will want to use newline ('\n') as the separator, and you might need to strip any trailing newline before splitting into words.

def click(): 
    text = text1.get("1.0", END).strip().split('\n')
    text2.insert(1.0, '\n'.join([f'a:{word}' for word in text]))