On Thu, Feb 6, 2014 at 3:59 PM, cool-RR <ram.rac...@gmail.com> wrote: > Hi, > > I'm curious. If I append an item to a list from the left using `list.insert`, > will Python always move the entire list one item to the right (which can be > super-slow) or will it check first to see whether it can just allocate more > memory to the left of the list and put the item there, saving a lot of > resources?
I'm pretty sure it'll slide all the existing elements right one position, and add at the leftmost position just opened up - assuming you're inserting at position 0. As was already mentioned, collections.deque is good for this sort of thing. It's implemented as a fancy doubly-linked list. Or rather, a doubly-linked list of smallish arrays/lists. For a singly-linked list: http://stackoverflow.com/questions/280243/python-linked-list http://stromberg.dnsalias.org/~strombrg/linked-list/ HTH -- https://mail.python.org/mailman/listinfo/python-list
