Best Practice for adding a script report in erpnext?

Should i create an app for creating script report for avoid problems in erpnext updation

can i create script report inside erpnext ?,deos it effect updation ?

if your script report useful for the community then add it to a core and send a pull request.

ok.i am beginner.do not know best practice for adding script report

Should i create an app for it