Yeah, the reconstruction isn't hard at all, but it's not a direct 1:1 mapping to the AST, since multiple control flow structures in the AST can become the same thing in bytecode. That said, it's quite simple to make it Good Enough (TM); the reason I wrote that and the RMarshal module was that I was writing a Python decompiler a part of a larger commercial project. I should release the decompiler at some point.