Tkinter's strange error

[Ponomarenko Pavlo]

What have caused it?

my_string = '1)from decimal import Decimal'

Error:
Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Python34\lib\tkinter\__init__.py", line 1538, in __call__
    return self.func(*args)
  File "C:/Users/Владелец/Desktop/programming/Pr_Python/Pr_Python.py", line 154, in find
    into_string.get_inf(output)
  File "C:/Users/Владелец/Desktop/programming/Pr_Python/Pr_Python.py", line 134, in get_inf
    reester.input_tk(k, road)
  File "C:/Users/Владелец/Desktop/programming/Pr_Python/Pr_Python.py", line 38, in input_tk
    road.insert(INSERT, my_string)
  File "C:\Python34\lib\tkinter\__init__.py", line 3145, in insert
    self.tk.call((self._w, 'insert', index, chars) + args)
_tkinter.TclError: invalid command name ".40584808"