Creating a list with holes

[Chris Angelico]

On Sat, Jan 4, 2014 at 1:58 PM, Dan Stromberg <drsalists at gmail.com> wrote:
> On Fri, Jan 3, 2014 at 7:37 AM, Chris Angelico <rosuav at gmail.com> wrote:
>> Depending on what exactly you need, it's probably worth just using a
>> dict. In what ways do you need it to function as a list? You can
>> always iterate over sorted(some_dict.keys()) if you need to run
>> through them in order.
>
> FWIW, sorting inside a loop is rarely a good idea, unless your lists
> are pretty small.

What do you mean by "sorting inside a loop"? I was thinking of this:

for key in sorted(some_dict.keys()):
    # blah blah

which will sort once and then iterate over it.

ChrisA