On Mar 7, 3:49 pm, "John" <[EMAIL PROTECTED]> wrote: > Then is there anyway to sort the numeric keys and avoid future implemetation > confusion? > > "Ant" <[EMAIL PROTECTED]> wrote in message > > news:[EMAIL PROTECTED] > > > On Mar 7, 8:18 pm, "John" <[EMAIL PROTECTED]> wrote: > > ... > >> However, I am not sure whether it is always like this. Can anybody > >> confirm > >> my finding? > > >>From the standard library docs: > > > "Keys and values are listed in an arbitrary order which is non-random, > > varies across Python implementations, and depends on the dictionary's > > history of insertions and deletions." > > > i.e. the behaviour you have discovered is an implementation detail, > > and could change in future versions.
I would consider that a bad choice. In the dictionary the keys are a set i.e. you might as well get a set() when you do d.keys() but the set() came later so you just get a list. The problem with a list is that somehow people want to make sense of it's order, just like in this case. So if instead of asking, he could have just written the application based on the fact that the keys will always be sorted in some way. But then one day his application maybe run a different platform and all of the sudden the keys are not sorted as before and then disaster strikes. I hope that dictionary.keys() would return a set to emphasize that keys are unordered. You suggested to just set a sort order and keep it consistent, but the problem is that then you _have to_ maintain the sort order in addition to the regular dictionary implementation (now it might just be a byproduct), that is extra work that will have to be done on every single insertion or deletion just for that rare use case where someone will want the keys to be sorted. -- http://mail.python.org/mailman/listinfo/python-list
