I've written Python code to calculate a bunch of things for a bunch of simulations. The code goes through about 5GB in 10-100MB chunks. The problem is that Python eventually runs out of memory, consuming (according to top) 3GB. I don't see why it should be doing this--as far as I know I'm not hanging on to any references of anything. I've fooled around with the garbage collector, turning debugging information on and trying to see if it will give me useful info about who or what is still hanging around in memory. I've tried to delete all the user variables but even after this the garbage collector can't free any more memory. What I need is du for python memory, just to get a sense of how/why this is happening. Anyone have suggestions about how to get traction on this? Thanks, Greg