Negative subscripts

[Chris Angelico]

On Sat, Nov 27, 2021 at 7:21 PM dn via Python-list
<python-list at python.org> wrote:
> The expression list is evaluated once; it should yield an iterable
> object. An iterator is created for the result of the expression_list.
> The suite is then executed once for each item provided by the iterator,
> in the order returned by the iterator. Each item in turn is assigned to
> the target list using the standard rules for assignments (see Assignment
> statements), and then the suite is executed. When the items are
> exhausted (which is immediately when the sequence is empty or an
> iterator raises a StopIteration exception), the suite in the else
> clause, if present, is executed, and the loop terminates.
> »
> https://docs.python.org/3/reference/compound_stmts.html#the-for-statement
>
>
> That said, I'm wondering if all is strictly true when the
> expression_list is a generator, which by definition features
> lazy-execution rather than up-front list production. So, things may
> depend upon the full-nature of the application.

Yes, it is. Evaluating a generator expression gives you a generator
object, which is an iterable.

ChrisA