I’m not sure why but the Mac has not installed a "/usr/bin/python3" so I continue to avoid 3.x migration (aside from minor things like "__future__" imports for

I’m not sure why but the Mac has not installed a "/usr/bin/python3" so I continue to avoid 3.x migration (aside from minor things like "__future__" imports for division and print_function). I don’t want to add a dependency for end users when my current code works fine with the built-in Python at 2.x. Nor do I want to bloat the size of downloads to embed something like an entire interpreter binary. (Swift has the same issue; there is currently no way to refer to it externally, as it is in flux; I do not want to embed loads of Swift libraries in every build so I will wait to migrate until they have stabilized binaries and made them available from a common root.)