One of the main advantages of mod_python is the increase in performance over traditional CGI. Below are results of a very crude test. The test was done on a 1.2GHz Pentium machine running Red Hat Linux 7.3. Ab was used to poll 4 kinds of scripts, all of which imported the standard cgi module (because this is how a typical Python cgi script begins), then output a single word "Hello!". The results are based on 10000 requests with concurrency of 1.
Standard CGI: 23 requests/s Mod_python cgihandler: 385 requests/s Mod_python publisher: 476 requests/s Mod_python handler: 1203 requests/s