Steven Bethard wrote: > > python -m timeit -s "data = [range(10) for _ in range(1000)]" > "sum(data, [])" > 10 loops, best of 3: 54.2 msec per loop > > > python -m timeit -s "data = [range(10) for _ in range(1000)]" "[w for > d in data for w in d]" > 100 loops, best of 3: 1.75 msec per loop > > The sum function used in this way (or a loop with a +=) is O(N**2) while the > LC is O(N).
also: timeit -s "data = [range(10) for _ in range(1000)]" "L = sum(data, [])" 10 loops, best of 3: 4.02e+004 usec per loop timeit -s "data = [range(10) for _ in range(1000)]" "L = [w for d in data for w in d]" 1000 loops, best of 3: 1.12e+003 usec per loop timeit -s "data = [range(10) for _ in range(1000)]" "L = []; map(L.extend, data)" 1000 loops, best of 3: 283 usec per loop timeit -s "data = [range(10) for _ in range(1000)]; from Tkinter import _flatten" "L = _flatten(data)" 1000 loops, best of 3: 308 usec per loop (the last one supports arbitrary nestings, the others don't) </F> -- http://mail.python.org/mailman/listinfo/python-list
