[Python-Dev] iterzip() (original) (raw)

Guido van Rossum guido@python.org
Mon, 29 Apr 2002 15:55:15 -0400

I get:

juststore 0.93 justtups 0.58 storetups 7.61 list.append is out of the picture here. Creating a million tuples goes fast so long as they're recycled, and storing a million things goes fast, but storing a million distinct tuples takes very much longer. It's a Mystery to me so far. How does it act on Linux?

Very reasonable with Python 2.2:

juststore 0.95 justtups 0.82 storetups 1.61

But with Python 2.3 it does just about as poorly as you saw on Windows:

juststore 0.91 justtups 0.82 storetups 9.40

Could it be that pymalloc somehow slows things down here? The 2.3 tupleobject.c is nearly unchanged from 2.2, so that can't be it.

If I double the array size, the 2.3 storetups time almost quadruples:

juststore 1.82 justtups 1.62 storetups 34.11

While with 2.2 it's nicely linear:

juststore 1.91 justtups 1.63 storetups 3.20

Bizarre, but I know you like a challenge. :-)

--Guido van Rossum (home page: http://www.python.org/~guido/)