Angular4 and WebApp2 on google App engine
You can use enviroment on angular in order to point you python rest service and another enviroment to production.
Example:
enviroment.ts

export const environment = {
  production: false,
  urlServices: 'http://190.52.112.41:8075'
};

enviroment.prod.ts

export const environment = {
  production: true,
  urlServices: 'http://localhost:8080'
};

In this way , you dont need to compile to test you aplication because angular always will be pointed to you python app.
I am currently using a angular4 projected generated by angular-CLI to create the project structure and I was able to serve it using ng-serve and develop and see changes. Now I would like to move it to being hosted on my own backend, using google app engine and webApp2 and run it using dev_appserver.py app.yaml. Currently the only way I can get it to work is by doing an ng-build and serving the files out of the dist folder. I would like to make it so I can easily make changes but not have to wait for it to rebuild each time.