[Baypiggies] len(iterable)

[Shannon -jj Behrens]

On Wed, Aug 6, 2008 at 1:11 PM, Tung Wai Yip <tungwaiyip at yahoo.com> wrote:
> I can think of 2 ways,
>
>>>> it = xrange(10)
>>>> len(list(it))
> 10
>
>>>> it = xrange(10)
>>>> sum(1 for i in it)
> 10
>
> Wai Yip
>
>
>> I have an iterable, and I want to find out how long it is.  I don't
>> care if it consumes the iterable.  Furthermore, I know the iterable is
>> not infinite.  Consider:
>>
>>>>> len((i for i in xrange(10)))
>> Traceback (most recent call last):
>>   File "<stdin>", line 1, in <module>
>> TypeError: object of type 'generator' has no len()
>>
>> It makes sense that len() not be defined, but I can't seem to find a
>> simple count function.  Of course, I can write one, but it seems like
>> it should exist in itertools or something.  (By the way, the count
>> function in itertools is something completely different.)
>>
>> Thanks,
>> -jj

I can't do len(list(iter)) because I don't have enough RAM ;)  Guido
and Wai Yip's idea was the most elegant.  It seems strange that this
isn't in the standard library.

-jj

-- 
Lisp programmers know the value of everything, but the cost of nothing...
On my Lisp, '() costs 4 bytes.
http://jjinux.blogspot.com/