The Traits project is at the center of all Enthought Tool Suite development and has changed the mental model used at Enthought for programming in the already extremely efficient Python programming language. The Traits project allows Python programmers to use a special kind of type definition called a trait, which gives object attributes some additional characteristics, such as Initialization, Validation, Delegation, Notification and Visualization. A class can freely mix trait-based attributes with normal Python attributes, or can opt to allow the use of only a fixed or open set of trait attributes within the class. Trait attributes defined by a classs are automatically inherited by any subclass derived from the class. WWW: https://pypi.python.org/pypi/traits/