The point is, we have already that tab-for-logical-indetation-space-for aligment for our C++ code. People are used to it, and it is known to accomodate a wide range of personal preferences. People also obviously have sufficiently capable editors, otherwise they'd be in trouble to have there patches accepted.
As I have said, this discussion can go on and on and on. But if python actually provides option -t and -tt, that treat mixing tabs/spaces as warning or error, we have no reason to do that. To the very least, using spaces only makes lyx more portable, in case some python purists wrap python as python -tt. Bo
