Standard 401 response when using HTTP auth in flask

Custom error responses are really quite easy in Flask. Create a function whose only argument is the HTTP error status code, make it return a flask.Response instance, and decorate it with @app.errorhandler.

@app.errorhandler(401)
def custom_401(error):
    return Response('<Why access is denied string goes here...>', 401, {'WWW-Authenticate':'Basic realm="Login Required"'})

You can then use abort(401) to your heart’s content.