import sys print(sys version split()[ ] :\codewhat py run per file directive :\codepy what py dittolatest againthe space after #is optionali added space to demonstrate the point here note that the first what py command here is equivalent to both an icon click and full py what pybecause the py exe program is registered to open py files automatically in the windows filename associations registry when the launcher is installed also note that when launcher documentation (including this appendixtalks about the latest versionit means the highest-numbered version that isit refers to the latest releasednot the latest installed on your computer ( if you install after #python selects the latterthe launcher cycles through the pythons on your computer to find the highest-numbered version that matches your specification or defaultsthis differs from the former last-installed-wins model nowchanging the first line name to python triggers the latest (reallyhighest-numbered installed instead here' this change at worki'll omit the last two lines of our script from this point on because they won' be altered#python rest of script unchanged :\codewhat py run with latest per #and you can request more specific version if needed--for exampleif you don' want the latest in python line#python :\codewhat py run with per #this is true even if the requested version is not installed--which is treated as an error case by the launcher#python :\codewhat py requested python version ( is not installed unrecognized unix #lines are also treated as errorsunless you give version number as command-line switch to compensateas the next section describes in more detail (and as the section on launcher issues will revisit as pitfall) appendix bthe python windows launcher