def eat_iterable(yummy_iterable):

    if isinstance(yummy_iterable, str):

        raise TypeError("BLECH! Strings are ATOMIC in this context, mmkay??")

    tasty_list = list(yummy_iterable)

    # digest list...

The design decision to make strs sequence-like was definitely a good one with a huge number of advantages. But we all know that sometimes, treating strs just like all other kinds of sequences is very inconvenient and isn't really what we want. 

This leads to isinstance() checking, which feels very non-python every time I do it. It would be kind of nice if list, tuple, and set had alt constructors that disallowed things that aren't REALLY sequences of individual atomic items-- like strs, and perhaps dicts as well (which is another instance check often needed to guard against errors).

Perhaps:

list.atomics

tuple.atomics

set.atomics

But naming things is hard and I'm terrible at it.