Secure python web app
Easiest and most secure: Put Apache or Nginx in front of it with an HTTPS proxy.
Update: Or VPN access as suggested by Jakob. Good idea.
i have python web app build on top of BaseHTTPServer, which runs on specyfic port. It runs system commands and shows output. I want do limit access to this app. What are posible ways to do it? Requirements:

it must not be limited to LAN
simple to implement/deploy