m...@pixar.com writes: > Is there any reason to prefer one or the other of these statements? > > if e.message.code in [25401,25402,25408]: > if e.message.code in (25401,25402,25408): > > I'm currently using [], but only coz I think it's prettier > than ().
Use a list when the semantic meaning of an item doesn't depend on all the other items: it's “only” a collection of values. Your list of message codes is a good example: if a value appears at index 3, that doesn't make it mean something different from the same value appearing at index 2. Use a tuple when the semantic meaning of the items are bound together, and it makes more sense to speak of all the items as a single structured value. The classic examples are point coordinates and timestamps: rather than a collection of values, it makes more sense to think of each coordinate set or timestamp as a single complex value. The value 7 appearing at index 2 would have a completely different meaning from the value 7 appearing at index 3. James Tauber explains this at <URL:http://jtauber.com/blog/2006/04/15/python_tuples_are_not_just_constant_lists/>. -- \ “Pinky, are you pondering what I'm pondering?” “Well, I think | `\ so, Brain, but pantyhose are so uncomfortable in the | _o__) summertime.” —_Pinky and The Brain_ | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
