how to save a matter number typed in tkinter textbox to a txt file and each new saved number to a new line

Question

Every time I save a new matter number from the tkinter textbox to the txt file, it replaces the previous one. I need it to save on the next line. Below is the code I've tried. Please assist. Thanks and All the best.

from tkinter import *

window = Tk()

window.geometry("700x250")


def save_text():
    text_file = open("matters.txt", "w")
    text_file.write(my_text_box.get(1.0, END))
    text_file.close()


label = Label(window, text = 'Save the matter number 👉 Matter number:').grid(row=3, column=1,)

my_text_box = Text(window, height=2, width=40).grid(row=3, column=2, padx=10, pady=12)

save = Button(window, text="Save matter", command=save_text).grid(row=3, column=3, padx=10, pady=10)

window.mainloop()

Answer 1

You need to open the file in "append" mode 'a' instead of "write" mode 'w' if you want to add content to an existing file. Try this instead:

def save_text():
    with open('matters.txt', 'a') as text_file:  # 'a' specifies 'append' mode
        text_file.write(my_text_box.get(1.0, END))

I've used a context manager here (the with statement) to make opening and closing the file a little cleaner as well