openapi code generator - python server stub workflow
To over come this problem I put my end point implementations into files in a openapi_server/implementation/ module and then I implemented a patching system in my build process.
I generate the server stub and then apply a patch to the server endpoint stubs in openapi_server/controller.
The patch includes adding various imports to endpoint implementation functions, replaces the  return 'do some magic!' lines with a calls to their end point implementations and even removes the # noqa: E501 comments where I don't want them.
With this system in place my openapi-generator can overwrite the openapi_server/controller directory each time it runs, and in the end I still end up with these files in a state that calls the implementations I need and any other tweaks I wanted have been applied.
I am using openapi-generator to generate server stub python code.
Everything works fine, however, every time I make a change in the OpenAPI specs (the yaml file), the code generator overwrites the whole code, even the one customized (the controller). I would like to develop an incremental workflow, where if I make a change in the specs, the generator modifies the code handling that part of the code only. 
It would be great if I get to the point where I can enforce the specs and also have an incremental workflow.
I am using openapi-generator version 3.3.4. 
I tried to modify the controller and remove # noqa: E501, but it still overwrites the code every time I generate the stub from the specs.
How can I isolate the controller implementation by the generated interface, since the generated code is not OOP?