Not so much DSLs, it's probably something as banal and ancient as usage = ( 'usage: foo [options] filenames...\n' ' -f force concatenation\n' '

Not so much DSLs, it's probably something as banal and ancient as usage = ( 'usage: foo [options] filenames...\n' ' -f force concatenation\n' ' -c for convenience\n' ) print usage Edit: forgot to add parentheses