This is a complete rewrite in Python. If you are comparing sar files, you don't have to first generate the data sets you want to compare to; sarvant will do it on the fly. A statistics feature has been added (use --stats to get stats printed to the graph). demfiles are no longer used to communicate with GNUPlot; instead, pipes are used via the gnuplot-py module. cat is used instead of mpage to concatenate postscript files.
