George Sakkis wrote:
One small side-effect of not being able to compare incompatible types in 3.0 is that None cannot be used any more as the smallest element. Yes this has always been an implementation artifact and a hack, but it was very convenient none the less. Is it maybe the right time to add a builtin Smallest (and also Largest) object, i.e. two singletons so that `Smallest < x` for every x: x is not Smallest and `Largest > x` for every x: x is not Largest ? Although it's not hard to define them in pure Python and one could object with "not every n-liner needs to be a builtin", the main added value is that these will be endorsed as the standard, otherwise we risk mymodule.Smallest clashing with with yourmodule.Smallest.
You can more-or-less take all of the replies to the thread about a blessed "__missing__" object and apply them to "Smallest"/"Largest". Using special objects to be lazy with your algorithm will never be wise. Eventually, someone will use them to mean something else entirely. It's almost always better to avoid using special objects or to roll-your-own (so that nobody can use it unexpectedly). Furthermore, preloading an output value with a nonsense value like "Smallest" or "Largest" is just asking for it to get leaked accidentally (the same problem exists with preloading None). -1 Let's not provide features for misguided programming idioms. -- Scott Dial scott@scottdial.com scodial@cs.indiana.edu