Virgil Stokes <v...@it.uu.se> writes: > Finally, to my question --- What is a fast way to write these > variables to an external file and then read them in backwards?
Seeking backwards in files works, but the performance hit is significant. There is also a performance hit to scanning pointers backwards in memory, due to cache misprediction. If it's something you're just running a few times, seeking backwards the simplest approach. If you're really trying to optimize the thing, you might buffer up large chunks (like 1 MB) before writing. If you're writing once and reading multiple times, you might reverse the order of records within the chunks during the writing phase. You're of course taking a performance bath from writing the program in Python to begin with (unless using scipy/numpy or the like), enough that it might dominate any effects of how the files are written. Of course (it should go without saying) that you want to dump in a binary format rather than converting to decimal. -- http://mail.python.org/mailman/listinfo/python-list
