martin@v.loewis.de (Martin v. Loewis):
But all other built-in constants have an initial capital letter: None, NotImplemented, Ellipsis, ...
Those you bring up are conceptually "objects", in the sense that you want to be aware of identity, whereas true and false are conceptually "values", in the sense that you never care about their identity, only about their state.
But the PEP explicitly defines them as singletons, so that you *can* rely on identity if you want. On that basis, they should have capital-letter names. Greg Ewing, Computer Science Dept, +--------------------------------------+ University of Canterbury, | A citizen of NewZealandCorp, a | Christchurch, New Zealand | wholly-owned subsidiary of USA Inc. | greg@cosc.canterbury.ac.nz +--------------------------------------+