MacPorts license unknown for Python-2.0

[contextnerror]

I encountered this issue when upt tried to package py-typing_extensions. (Because upt -r checked for a hypen and not underscore, it didn't realize the port already existed.)
It seems like the correct MacPorts license equivalent should be PSF?

[Steap]

Seems like we need one more entry in https://github.com/macports/upt-macports/blob/master/upt_macports/spdx2macports.json . I'm not sure abut the MacPorts equivalent. @reneeotten do you have any idea?