Python Zero Cost Exceptions

In previous releases of Python, there was a little bit of overhead to set up the mechanisms of potentially handling the errors and information you needed. That's down to more or less two now. And frames are just more anyway because of the zero cost exceptions, which I think we mentioned on the release thing. But yeah, this is well, tell people about zero cost exceptions. They're pretty low cost if you don't have an exception, but they tend to be even more expensive if you do get an exception.