tkinter and stdout redirection

[nathan]

Hi all,
newbie here..

if I redirect the output stream in a file with

sys.stdout = open ("file", "w")

direct from the command prompt, I get the output  stream in my file without
any problems.

But if I do the same from a tkinter application , I get the output stream
only when I close the application.
I think  that there's a buffer between the output stream and my file, but
I've not found anywhere how to set it.
Someone can help me?
Thank you

N.