actioncoded in our original what py script#!python :\codewhat py same as #!/usr/bin/python run per launcher default the default is also applied when no directive is present at all--perhaps the most common case for code written to be used on windows primarily or exclusivelynot launcher directive :\codewhat py also run per default :\codepy what py ditto but you can set the launcher' default to with initialization file or environment variable settingswhich will apply to both files run from command lines and by icon clicks via their name' association with py exe or pyw exe in the windows registrynot launcher directive :\codewhat py run per default :\codeset py_python= :\codewhat py or via control panel/system run per changed default as suggested earlierfor more fine-grained control you can also set version-specific environment variables to direct partial selections to specific releaseinstead of falling back on the installed release with the highest minor number#!python :\codepy what py runs "latest :\codeset py_python = :\codepy what py use py_python for override highest-minor choice the set used in these interactions applies to its command prompt window onlymaking such settings in the control panel' system window will make them apply globally across your machine (see appendix for help with these settingsyou may or may not want to set defaults this way depending on the majority of the python code you'll appendix bthe python windows launcher