tkinter: get filename of askopenfilename

[rom]

Hi there,

I am writing an interface with Tkinter. My minimal program looks like
this:
#############
import Tkinter
import tkFileDialog

root = Tkinter.Tk()

Tkinter.Button(root, text='Notch genes...', command=lambda:
open_file_dialog()).pack()

def open_file_dialog():
    filename = tkFileDialog.askopenfilename(filetypes=[("all
files","*")])

# print filename

root.mainloop()
#############

I would like to recover the filename variable outside the
"open_file_dialog" function. For instance, to be able to print the
selected file name (uncomment "# print filename" line).

Is there a way to do that?

Thanks in advance.

R