John Machin wrote: > On Sat, 07 May 2005 02:29:48 GMT, [EMAIL PROTECTED] (Bengt Richter) wrote: > > >>On Sat, 07 May 2005 11:08:31 +1000, Maurice LING <[EMAIL PROTECTED]> wrote: >> >>>It doesn't seems to help. I'm thinking that it might be a SOAPpy >>>problem. The allocation fails when I grab a list of more than 150k >>>elements through SOAP but allocating a 1 million element list is fine in >>>python. >>> >>>Now I have a performance problem... >>> >>>Say I have 3 lists (20K elements, 1G elements, and 0 elements), call >>>them 'a', 'b', and 'c'. I want to filter all that is in 'b' but not in >>>'a' into 'c'... >>> >>> >>>>>>a = range(1, 100000, 5) >>>>>>b = range(0, 1000000) >>>>>>c = [] >>>>>>for i in b: >>> >>>... if i not in a: c.append(i) >>>... >>> >>>This takes forever to complete. Is there anyway to optimize this? >>> >> >>Checking whether something is in a list may average checking equality with >>each element in half the list. Checking for membership in a set should >>be much faster for any significant size set/list. I.e., just changing to >> >> a = set(range(1, 100000, 5)) >> >>should help. I assume those aren't examples of your real data ;-) >>You must have a lot of memory if you are keeping 1G elements there and >>copying a significant portion of them. Do you need to do this file-to-file, >>keeping a in memory? Perhaps page-file thrashing is part of the time problem? > > > Since when was 1000000 == 1G?? > > Maurice, is this mucking about with 1M or 1G lists in the same > exercise as the "vm_malloc fails when allocating a 20K-element list" > problem? Again, it might be a good idea if you gave us a little bit > more detail. You haven't even posted the actual *PYTHON* error message > and stack trace that you got from the original problem. In fact, > there's a possible interpretation that the (system?) malloc merely > prints the vm_malloc message and staggers on somehow ... > > Regards, > John
This is the exact error message: *** malloc: vm_allocate(size=9203712) failed (error code=3) *** malloc[489]: error: Can't allocate region Nothing else. No stack trace, NOTHING. maurice -- http://mail.python.org/mailman/listinfo/python-list
