[omaha] Iterators vs Generator!!

[Varun Mehta]

Thank you Jeff for the crisp inputs.
That is exactly what i was looking for.

Varun

On Oct 27, 2014, at 11:09 PM, Jeff Hinrichs - DM&T <jeffh at dundeemt.com> wrote:

> The primary difference is that generators are not reusable.  see
> http://pymbook.readthedocs.org/en/latest/igd.html for additional
> information.
> 
> essentially, when you hit the end of your generator, because it holds
> state, it keeps saying, "stop iteration" by returing None and not yield'ing
> a value.  Where an iterator has no state.  When it goes out of scope, like
> in a "for" block, the next time you use it, it starts over.
> 
> You can make a generator reusable, but it takes work and purpose, since you
> are working against it's reason for existing and attempting to turn it back
> into a more general iterator.
> 
> Best,
> Jeff
> 
> On Mon, Oct 27, 2014 at 7:19 PM, Varun Mehta <varun.sagi20 at gmail.com> wrote:
> 
>> Thank you for inputs Wes.
>> 
>> I guess i’ll find my answers in one of the links.
>> 
>> -Varun
>> 
>> On Oct 27, 2014, at 7:07 PM, Wes Turner <wes.turner at gmail.com> wrote:
>> 
>>> Both iterators and generators can be functionally composed.
>>> 
>>> Generators can maintain local state as they are iterated through.
>>> 
>>> Learning not to consume iterators and generators is a good thing; both
>> for
>>> Python 3 (where things like .keys() are now .iterkeys()) and for asyncio
>>> ("yield from").
>>> 
>>> An object can implement .__iter__() /.next()) and not .__len__().
>>> 
>>> Docs:
>>> 
>>> 
>> https://docs.python.org/2/reference/datamodel.html#the-standard-type-hierarchy
>>> 
>>> https://docs.python.org/2/glossary.html#term-generator
>>> 
>>> https://docs.python.org/2/glossary.html#term-iterator
>>> 
>>> https://docs.python.org/2/tutorial/classes.html#generators
>>> 
>>> https://docs.python.org/2/howto/functional.html#iterators
>>> 
>>> https://docs.python.org/2/tutorial/classes.html#iterators
>>> 
>>> https://docs.python.org/2/library/itertools.html
>>> 
>>> 
>> https://scipy-lectures.github.io/advanced/advanced_python/index.html#iterators-generator-expressions-and-generators
>>> 
>>> https://docs.python.org/3/library/asyncio.html (3.4+)
>>> 
>>> Tools for working functionally with iterators and generators:
>>> 
>>> https://github.com/pytoolz/toolz
>>> 
>>> https://github.com/kachayev/fn.py/blob/master/README.rst
>>> 
>>> http://funcy.readthedocs.org/en/latest/
>>> On Oct 27, 2014 4:02 PM, "Varun Mehta" <varun.sagi20 at gmail.com> wrote:
>>> 
>>>> Hi all
>>>> 
>>>> I have a query regarding the Iterator vs Generator.
>>>> Generator is specific type of Iterator.
>>>> But both still use next function to produce next value and save memory.
>>>> 
>>>> So, which should be preferred?
>>>> Any advantage of one over other?
>>>> 
>>>> Warm Regards
>>>> Varun Mehta
>>>> 
>>>> 
>>>> 
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> 
> 
> 
> -- 
> Best,
> 
> Jeff Hinrichs
> 402.218.1473
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