Rename RENDER OUTPUT ? [SOLVED]

hi!
is there a way to set the name of the render output like instead of the frame numbers for a avi just a name like FILM.avi ?

i only found this:
os.rename( sys.expandpath(outfile+’#’), outfile )
but
get this
TypeError: unsupported operand type(s) for +: ‘Blender RenderData’ and ‘str’

when runnin !?

THANXX

SOLVED:

os.chdir("C:/tmp")
os.rename('0001_0200.avi','FILM.avi')

i love python !