# first example
import os
here = lambda x: os.path.join(os.path.abspath(os.path.dirname(__file__)), x)

# usage
MEDIA_ROOT = here('media')

# second example, cross platform
import os
here_cross = lambda x: os.path.join(os.path.abspath(os.path.dirname(__file__)), *x)

# usage
MEDIA_ROOT = here_cross(('files','media'))