string issue

[rbt]

Bill Mill wrote:
> On Fri, 04 Feb 2005 15:25:04 -0500, rbt <rbt at athop1.ath.vt.edu> wrote:
> 
>>John J. Lee wrote:
>>
>>>Steve Holden <steve at holdenweb.com> writes:
>>>[...]
>>>
>>>
>>>>You are modifying the list as you iterate over it. Instead, iterate
>>>>over a copy by using:
>>>>
>>>>for ip in ips[:]:
>>>>  ...
>>>
>>>
>>>Just to help popularise the alternative idiom, which IMO is
>>>significantly less cryptic (sane constructors of mutable objects
>>>almost always make a copy, and list is no exception: it's guaranteed
>>>to do so):
>>>
>>>for ip in list(ips):
>>>   ...
>>>
>>>
>>>Works back to at least Python 1.5.2.
>>>
>>>
>>>John
>>
>>I don't know that that approach is less cryptic. ips is already a
>>list... it looks cryptic to make it a list again, doesn't it? IMO, the
>>two are equally cryptic. The epitome of clarity would be copy(ips)...
>>now *that* makes sense, of course, ips[:] or list(ips) work equally well
>>to the programmer who has learned them.
> 
> 
> Howsabout:
> 
> 
>>>>from copy import copy
>>>>ips = ['255.255.255.255', '128.173.120.79', '198.82.247.98',
> 
> ... '127.0.0.1', '255.0.0.0', '255', '128.173.255.34']
> 
>>>>for ip in copy(ips):
> 
> ...     if '255' in ip:
> ...             ips.remove(ip)
> ...
> 
>>>>ips
> 
> ['128.173.120.79', '198.82.247.98', '127.0.0.1']
> 
> But I still think that the list comprehension is the best.
> 
> Peace
> Bill Mill
> bill.mill at gmail.com

Wow, I did not know that a copy module existed. I made all that up about 
copy being the perfect example here. Great minds think alike ;) I fell 
Guidoish.