[golang][python] Different client behaviour between go-client and python-client

Description

go-client isn't enforcing required properties of inner object that aren't set at all while python-client is.

outer-type:
  type: object
  properties:
    inner-type:
      type: object
    other-object:
    ...

inner-type:
  type: object
  required:
    - a
    - b
  properties:
    a:
      type: string
    b:
      type: string

If I use an API that required outer-type as a parameter but I don't set inner-type at all in it:

• go-client won't enforce setting a and b properties (this is the better option IMO as we don't want any inner-type in the request)
• python-client will enforce it though, which means that on each API call I have to manually set ALL the required fields of all the nested objects (even if I don't want their parent objects at all).

The best UX to me would have been to enforce only the required properties of the objects that were explicitly created in the request.

Swagger-codegen version

Reproduced on 2.4.15 and on 2.4.21

Swagger declaration file content or URL

swagger.yaml

Command line used for generation

function generate_go_client() {
    rm -rf client models
    docker run -u $(id -u):$(id -u) -v ${__root}:${__root}:rw,Z -v /etc/passwd:/etc/passwd -w ${__root} \
        quay.io/goswagger/swagger:v0.25.0 generate client --template=stratoscale -f swagger.yaml \
        --template-dir=/templates/contrib
}

function generate_python_client() {
    local dest="${BUILD_FOLDER}"
    rm -rf "${dest}"/assisted-service-client/*

    docker run --rm -u "$(id -u)" --entrypoint /bin/sh \
        -v "${dest}":/local:Z \
        -v "${__root}"/swagger.yaml:/swagger.yaml:ro,Z \
        -v "${__root}"/tools/generate_python_client.sh:/script.sh:ro,Z \
        -e SWAGGER_FILE=/swagger.yaml -e OUTPUT=/local/assisted-service-client/ \
        quay.io/ocpmetal/swagger-codegen-cli:2.4.15 /script.sh
     cd "${dest}"/assisted-service-client/ && python3 setup.py sdist --dist-dir "${dest}"
     cd "${dest}"/assisted-service-client/ && python3 "${__root}"/tools/client_package_initializer.py "${dest}"/assisted-service-client/  https://github.com/openshift/assisted-service --build
}

Steps to reproduce

1. clone the repo assited-service - make sure you got that specific branch.
2. skipper make generate-all
   You can install skipper from here

Suggest a fix/enhancement

Make python-client act like go-client

Start with the linked swagger.yaml and reproduce generation using the shown generate_go_client and generate_python_client commands, including tools/generate_python_client.sh. Compare validation of an omitted inner-type between the generated clients; done means the Python client no longer requires fields from nested objects that were not explicitly created.