Message 86264 - Python tracker

Thanks, Terry.

I think the only changes I'll make are:

arg_name: (`identifier` | `integer`)*
should be:
arg_name: (`identifier` | `integer`)?

And leave:
conversion: "r" | "s"
instead of:
conversion: "r" | "s" | "a"
because 'a' isn't valid in 2.7.