Vue app doesn't load when served through Python Flask server
flask renders its variables with jinja2 which uses {{ variable }} as its parsing delimiter
render("mytemplate.html",message="Hello") would replace all {{ message }} blocks with "Hello" before any javascript is handled ... since you dont define message it is simply an empty string... you will need to configure vue to use alternative delimiters (I use [[ message ]])
<!doctype html><html><head> <meta http-equiv="content-type" content="text/html; charset=utf-8" /> <script type="text/javascript" src="https://unpkg.com/vue"></script> </head><body> <div id="app"> Message: [[ message ]] </div> <script> var vm = new Vue({ el: "#app", delimiters : ['[[', ']]'], data: { message: "Hello, world" } });</script> </body></html>