[Python-Dev] iterzip()

2002年4月29日 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/)