Thanks, its indeed a very nice addition to the library...
Just a marginal remark; it seems, that in script-names also some non BMP characters are covered, however, in the unicode ranges thee only BMP.
http://www.unicode.org/Public/UNIDATA/Blocks.txt

Am I missing something more complex, as why 
10000.. - ..10FFFF; ranges weren't included in _BLOCKS ?
Maybe building these ranges is expensive, in contrast to rare uses of these properties?

(Not that I am able to reliably test it on my "narrow" python build on windows, but currently, obviously, e.g. \p{InGothic} gives "undefined property name" whereas \p{Gothic} is accepted.)

vbr