[Python-ideas] Use the plus operator to concatenate iterators

[Sven R. Kunze]

1) It always sucks when moving from lists to iterators.
2) As you showed, transition to Python 3 is made easier.

Thus: +1 for me

On 05.08.2015 02:22, Grayson, Samuel Andrew wrote:
> Concatenation is the most fundamental operation that can be done on 
> iterators. In fact, we already do that with lists.
>
>     [1, 2, 3] + [4, 5, 6]
>     # evaluates to [1, 2, 3, 4, 5, 6]
>
> I propose:
>
>     iter([1, 2, 3]) + iter([4, 5, 6])
>     # evaluates to something like itertools.chain(iter([1, 2, 3]), 
> iter([4, 5, 6]))
>     # equivalent to iter([1, 2, 3, 4, 5, 6])
>
> There is some python2 code where:
>
>     a = dict(zip('abcd', range(4)))
>     isinstance(a.values(), list)
>     alphabet = a.keys() + a.values()
>
> In python2, this `alphabet` becomes a list of all values and keys
>
> In current python3, this raises:
>
>     TypeError: unsupported operand type(s) for +: 'dict_keys' and 
> 'dict_values'
>
> But in my proposal, it works just fine. `alphabet` becomes an iterator 
> over all values and keys (similar to the python2 case).
>
> Sincerely,
> Sam G
>
>
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