Delete all items in the list

Chris Rebert clp2 at rebertia.com
Fri Feb 27 01:39:50 CET 2009


On Thu, Feb 26, 2009 at 4:37 PM, Gabriel Genellina
<gagsl-py2 at yahoo.com.ar> wrote:
> En Thu, 26 Feb 2009 22:18:18 -0200, Chris Rebert <clp2 at rebertia.com>
> escribió:
>>
>> On Thu, Feb 26, 2009 at 4:08 PM, Peter Billam <peter at www.pjb.com.au>
>> wrote:
>>>
>>> On 2009-02-26, Clarendon <jineu21 at hotmail.com> wrote:
>>>>
>>>> Hi. This must be a simple command but I just can't find it in the
>>>> Phthon manual. How do I delete all items with a certain condition from
>>>> a list? For instance: > L=['a', 'b', 'c', 'a']
>>>> I want to delete all 'a's from the list.  > But if L.remove('a')
>>>> only deletes the first 'a'.  How do you delete all 'a's?
>>>
>>> L2 = list(set(L))
>>>
>>> works for me...
>>
>> A. That doesn't by itself remove all the 'a's, although it does remove
>> all but 1 'a'
>> B. That also removes all but one instance of *everything* in the list,
>> not just 'a'
>> C. That is lossy in that it completely loses the ordering of the original
>> list
>
> I said the very same things!
> There are other issues too, like this only works with hashable objects, but
> I've chosen exactly the same remarks and exactly in the same order! What a
> coincidence...

Indeed, USENET and mail<->news lags doth create interesting situations
sometimes.

Cheers,
Chris

-- 
Follow the path of the Iguana...
http://rebertia.com



More information about the Python-list mailing list