[Python-ideas] Make len() usable on a generator

[random832 at fastmail.us]

On Fri, Oct 10, 2014, at 19:34, Andrew Barnert wrote:
> The if example is a good illustration of this. If a genexpr is a sequence
> iff it has exactly 1 for clause and 0 if clauses

Why not 2 for clause? Won't its length always be the product of the two
inputs, then? (And you forgot if its inputs are sequences)

More to the point, since python isn't statically typed, there's no
reason that user code would have to produce a view (though I'd suggest
it should at least produce an "iterable" that next can't be called
directly on without iter - a paradigm that has worked well for Java and
C#) if it doesn't want to.