How can I include python module from an outer folder in the docker image?

I have 2 services in one git repository written in the python and deployed to the containers with docker-compose and docker. And I wanted to add some authorization with the third party OpenID Connect service. I have written a module to deal with authorization and I desire to use it in every service.
My repository looks like this:

services:
    first_service:
        Dockerfile
        docker-compose.yml
        first_service_python_module
    second_service:
        Dockerfile
        docker-compose.yml
        second_service_python_module
    docker-compose.yml
    .git

Initially, I wanted my authorization module to be in the ‘services’ folder but this way I cannot build my Docker images because Docker can’t deal with the outer folder without special argument.
But I cannot specify this argument because of docker-compose files.
So I ended up with the next repository structure:

services:
    first_service:
        Dockerfile
        docker-compose.yml
        first_service_python_module
        authorization_module
    second_service:
        Dockerfile
        docker-compose.yml
        second_service_python_module
        authorization_module
    docker-compose.yml
    .git

Obviously there is a lot of code duplication and it’s hard to maintain.

I want to avoid code duplication. But also not to change docker and docker-compose files a lot. How can I do it?

Source: StackOverflow