No, that doesn't work. Java has something like this (synchronized methods) but they are cumbersome (I find programming nicer with plain old locks and conditions

No, that doesn't work. Java has something like this (synchronized methods) but they are cumbersome (I find programming nicer with plain old locks and conditions, the Java synchronized model feels just a layer of cruft but its all lock&cond inside). But Python is different than Java. The Python interpreter has to guard the internal data structures of the interpreter itself, and that is a lot more tricky than it seems on the surface.