Is there a canonical way to check whether an iterable is ordered?

[Steven D'Aprano]

cool-RR wrote:

> My function gets an iterable of an unknown type. I want to check whether
> it's ordered. I could check whether it's a `set` or `frozenset`, which
> would cover many cases, but I wonder if I can do better. Is there a nicer
> way to check whether an iterable is ordered or not?

See the collections.abc module:

https://docs.python.org/3/library/collections.abc.html

I think what you want is:

import collections.abc
isinstance(it, collections.abc.Sequence)

Prior to 3.3, you would use:

# Untested.
import collections
isinstance(it, collections.Sequence)



-- 
Steven