Quoth rdmur...@bitdance.com: > This is all premature optimization, except for the goopy code, which is > presumably used enough to make it worth optimizing. And guess what? > The goopy code wins. What the people theorizing about the speed of > extend vs list creation miss is that the things with high overhead in the > above functions are (1) isinstance and (2) the recursive function call. > The goopy code avoids this by using type and is, and by unrolling the > lowest level without a function call. On the other hand, extend > _is_ faster than append if you aren't creating a new list, so the > goopy code can be optimized a little more. > > I remembered the bit about high function call overhead, but the rest > of it measured:
Oooh, that's embarrassing. Not only didn't I read the code carefully enough, I didn't test the actual output of the functions. The goopy code doesn't flatten to arbitrary depth, so of course it is faster. --RDM -- http://mail.python.org/mailman/listinfo/python-list
