string issue

[rbt]

Thanks guys... list comprehension it is!

Bill Mill wrote:
> On Fri, 04 Feb 2005 14:23:36 -0500, rbt <rbt at athop1.ath.vt.edu> wrote:
> 
>>Either I'm crazy and I'm missing the obvious here or there is something
>>wrong with this code. Element 5 of this list says it doesn't contain the
>>string 255, when that's *ALL* it contains... why would it think that???
>>
>>import time
>>
>>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 ips:
>>     if '255' in ip:
>>         try:
>>             print "Removing", ip
>>             ips.remove(ip)
>>         except Exception, e:
>>             print e
>>
>>print ips
>>time.sleep(5)
>>
> 
> 
> You're gong crazy:
> 
> 
>>>>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 ips:
> 
> ...     if '255' in ip: print ip
> ...
> 255.255.255.255
> 255.0.0.0
> 255
> 128.173.255.34
> 
> The problem is that you're operating in-place on an array while it's
> being iterated over. Since the iterator is only created once, you're
> can't change the array while you're iterating over it. Instead, try a
> list comprehension:
> 
> 
>>>>ips = [ip for ip in ips if '255' not in ip]
>>>>ips
> 
> ['128.173.120.79', '198.82.247.98', '127.0.0.1']
> 
> Peace
> Bill Mill
> bill.mill at gmail.com