Open Command Prompt as Administrator and type netstat -ano | findstr :11501 . Find the PID number at the end of the line, then type taskkill /PID [NUMBER] /F to force it closed.
Whether you’re using Flask, Django, or a simple python -m http.server , Python’s development servers can bind to any port. By default, Python’s HTTP server uses port 8000, but you can specify any available port.