Hm, I didn't mean to argue against all type checks, just the flavor of static typing as described by the OP (i.e., Java). I don't consider Haskell's type system

Hm, I didn't mean to argue against all type checks, just the flavor of static typing as described by the OP (i.e., Java). I don't consider Haskell's type system "rigid"; it's strict as hell, but it's also very expressive. Either way, both flavors of static typing require development methods that are very different from Python's, though. My original point was that in Python, you shouldn't really have to worry about types, or checking them (in tests or otherwise). You can, but (IMHO) you'd be going against the grain of the language.