Comment by jaster

  > cat test.py 
  import sys
  if sys.version_info.major < 3:
      raise Exception("this script requires python version >= 3")
  
  print(f"test")
  
  > python2 test.py
    File "test.py", line 5
      print(f"test")
                  ^
  SyntaxError: invalid syntax

Doesn't seem that simple