Merge sorted lists in python
arrays, merge, python, sorting
Solution
Python standard library offers a method for it: `heapq.merge`. As the documentation says, it is very similar to using itertools (but with more limitations); if you cannot live with those limitations (or if you do not use Python 2.6) you can do something like this:
sorted(itertools.chain(args), cmp)
However, I think it has the same complexity as your own solution, although using iterators should give some quite good optimization and speed increase.
Problem
I have a bunch of sorted lists of objects, and a comparison function ``` class Obj : def __init__(p) : self.points = p def cmp(a, b) : return a.points < b.points a = [Obj(1), Obj(3), Obj(8), ...] b = [Obj(1), Obj(2), Obj(3), ...] c = [Obj(100), Obj(300), Obj(800), ...] result = magic(a, b, c) assert result == [Obj(1), Obj(1), Obj(2), Obj(3), Obj(3), Obj(8), ...] ``` what does `magic` look like? My current implementation is ``` def magic(*args) : r = [] for a in args : r += a return sorted(r, cmp) ``` but that is quite inefficient. Better answers?