Application configuration has 3 or 4 avenues

i was reading about a new command-line tool. And here is what I have to say:

To be complete, applications should be able to be configured

1. At the command line
2. In a confile file
3. Via OO manipulation of attributes

AFAIK, only Traitlets allows me all 3…. and gives me a command-line interface automatically just by defining the attributes of my objects.