Yesterday, a coworker and I were working on a performance issue we'rehaving with our new SAN RAID controller. We had a hypothesis about whatmight provoke the problem, so we sat down, fired up some tests, andwatched our logs; nothing showed up. Later on in the day, we saw someodd indications in other logs and wanted to see if they correlated withthe tests we'd done, but you can already guess the punchline: we hadn'trecorded when we started and stopped

Like most organizations, the university has what I call administrativemanagement systems , the computers thathandle core business record keeping like payroll, accounts payableand receivable, HR, and (this being a university) crucial studentinformation like enrollment and marks. This is serious stuff, runusing expensive software on expensive databases on expensive hardware(and behind paranoid firewalls), and, like most places, is considered apretty crucial thing.

But it turns out that it has quietly become not the most crucialsystem the university runs.

Over the course of the Python code that I've written, I've noticedcertain patterns that seem to reoccur relatively frequently. One ofmy common ones is a pattern that I'll call the Mutating Proxy.

Python doesn't have much use for plain proxy objects, objects thatjust relay things to another one, since duck typing means that you canusually just use the original object instead. A mutating proxy is aproxy that's used in order to change the behavior of the underlyingobject,