[Python-ideas] Indicate if an iterable is ordered or not

[Mark Janssen]

> Iterables are not necessarily ordered (e.g. dict vs. OrderedDict).
> Sequences are but Sets aren't.  I'm not aware of any good way
> currently to know if an arbitrary iterable is ordered.  Without an
> explicit indicator of ordered-ness, you must know in advance for each
> specific type.
>
> One possible solution is an __isordered__ attribute (on the class),
> set to a boolean.  The absence of the attribute would imply False.

Isn't the traditional way to do this via "inheritance"?  Then you call
issubclass(list, OrderedContainer), etc.

But, then, no Python hasn't completely ordered its data structures yet.

Mark