multiple dockerfiles

I have a python application that I need to put into a docker. Since I need the docker to be able to run on windows servers and linux servers, its best to create two separate docker images, one for each operating system. Since docker is composed using docker files, and each docker image is a derivation of prebuilt docker images and they are already build with different operating systems in them, I need to have different docker files for each pipeline. However, docker does not allow to have multiple docker files and only allows one docker file named "Dockerfile" in a folder with code. How can I create multiple docker files for multiple pipelines?