Why Drone CI can be interesting for you? Example of Bitbucket Pipelines configuration using YAML anchors and aliases

bitbucket-pipelines.yml

definitions:
  caches:
    poetry-path: /root/.poetry
    poetry-venv: /root/.cache/pypoetry/virtualenvs

  steps:
    - step: &step-37
        image: python:3.7
        caches:
          - poetry-path
          - poetry-venv

    - step: &step-38
        image: python:3.8
        caches:
          - poetry-path
          - poetry-venv

  scripts:
    - script: &script-install poetry install -vv
    - script: &script-test poetry run pytest .

pipelines:
  default:
    - step:
        <<: *step-37
        name: deps-3.7
        script:
          - *script-install
    - step:
        <<: *step-38
        name: deps-3.8
        script:
          - *script-install
    - step:
        <<: *step-38
        name: lint-3.8
        script:
          - poetry run black --check --diff .
          - poetry run flake8 .
          - poetry run isort --check-only --diff --recursive
    - step:
        <<: *step-37
        name: test-3.7
        script:
          - *script-test
    - step:
        <<: *step-38
        name: test-3.8
        script:
          - *script-test
    - step:
        <<: *step-38
        name: publish-3.8
        script:
          - poetry publish --build