Error when non-English characters present

When the user inserts non-English characters, the script stops with an error.

# -*- coding: utf-8 -*-
from Tkinter import *
wnd = Tk()
name_A = Entry(wnd)
name_A.pack()
def AAAA1():
     A1 = name_A.get()
     with open("file_name.TXT", 'w') as f:
        f.write(A1)
Button(wnd, text="GO", command=AAAA1).pack()
wnd.mainloop()

UnicodeDecodeError: 'ascii' codec can't decode byte 0xd7 in position 0: ordinal not in range(128