myFormats = [('Windows Bitmap', '*.bmp'), ('Portable Network Graphics',
    '*.png'), ('JPEG / JFIF', '*.jpg'), ('CompuServer GIF', '*.gif')]
root = Tkinter.Tk()
fileName = tkFileDialog.asksaveasfilename(parent=root, filetypes=myFormats,
    title='Save the image as...')
if len(fileName) > 0:
    pass
Browse a Windows directory GUI using Python 2.7