Interesting feature abuse. Perl's had various Inline modules for some time, but via a deliberate feature. https://www.perl.com/pub/2001/02/inline.html/
Indeed it is. Guido himself maintained a project called Pyxl3 [1] for a while (forked from one at Dropbox during his tenure there) that abused this codec feature to implement something similar to JSX within Python source.