list() strange behaviour

[Cameron Simpson]

On 23Jan2021 12:20, Avi Gross <avigross at verizon.net> wrote:
>I am wondering how hard it would be to let some generators be resettable?
>
>I mean if you have a generator with initial conditions that change as it
>progresses, could it cache away those initial conditions and upon some
>signal, simply reset them? Objects of many kinds can be set up with say a
>reinit() method.

On reflection I'd do this with a class:

    class G:
        def __init__(self, length):
            self.length = length
            self.pos = 0

        def __next__(self):
            pos = self.pos
            if pos >= length:
                raise StopIteration()
            self.pos += 1
            return pos

        def __iter__(self):
            return self

then:

    g = G(9)
    for x in g:
        print(x)
        if x == 5:
            g.pos = 7

You could either fiddle the iterable class instance attributes directly 
as above or provide a reset method of some kind.

If you don't need to fiddle/reset you can just write:

    for x in G(9):

The two step above is so we have "g" to hand to do the fiddling.

Cheers,
Cameron Simpson <cs at cskk.id.au>