reduce expression to test sublist
Dave Angel
d at davea.name
Sat Jan 5 17:05:20 EST 2013
On 01/05/2013 04:55 PM, Terry Reedy wrote:
> On 1/5/2013 1:58 PM, Dave Angel wrote:
>
>> If you're trying to make a faster loop, then I suggest you look into set
>> differences. Turn both lists into sets, and subtract them. Something
>> like (untested):
>>
>> result = not bool( set(lst1) - set(lst2) )
>
> This does not return False as soon as an item in set1 is found that is
> not in set2.
>
> set(lst1) < set(lst2)
>
> will, and directly return False/True. The OP is trying to compute the
> lst1 < lst2, where lst1 and lst2 are interpreted as sets, rather than
> as sequences with the lexicographic ordering default.
>
Thanks. I wasn't aware that sets supported ordered comparison that way,
though it makes perfect sense now that you point it out.
--
DaveA
More information about the Python-list
mailing list