Comment by dec0dedab0de

What I'm describing was just a desire for a very simple "this script requires python version >= X" error, with the ability to write unfettered python version X code below it, in a single file script.

  import sys
  if sys.version_info.major < 3:
    raise Exception("this script requires python version >= 3") 

plus an extra line or two if you're worried about minor versions.