Pebblestone: >I heard that python's list is implemented as adjustable array.
Correct, an array geometrically adjustable on the right. >Here's my lisp implementation:< What's the memory size of a before computing b? You can compare it with Python, that may need less memory (because the array contains pointers). >BTW, I couldn't install psyco on my system (ubuntu), gcc just prompt to me >thousands of lines of errors and warnings.< Find a Win box ;-) It's already compiled for it (for Py 2.3, 2.4). >Your python's example (use direct index array index) of my corresponding lisp >code works slower than the version which use 'append'.< For me (a slow PC) it's almost twice faster, computer life is usually complex. For me using the esplicit allocation + Psyco makes that program about 4 times faster (from 8 to 2 seconds). >This let me think how python's list is implemented.< You also have to think how the * allocation is implemented and many other things :-) The list implementation is rather readable, Python sources are online too. >Anyway, python's list is surprisingly efficient.< But its access isn't that fast :-) Psyco helps. Bye, bearophile -- http://mail.python.org/mailman/listinfo/python-list