setup-python.yml

- name: Setup Python environment
  hosts: all
  become: yes
  tags: python
  tasks:

    - name: add PPA with extra python versions
      apt_repository:
        repo: ppa:deadsnakes/ppa
        codename: "{{ dist_override | default(omit) }}"
        filename: "python-deadsnakes"

      # NEVER mix pip installation methods (e.g. via apt and pip), see
      # https://github.com/pypa/pip/issues/5221#issuecomment-382069604
    - name: install distro python apt packages
      apt:
        name:
          - "{{ item }}-pip"  # may not be present by default
          - "{{ item }}-setuptools"  # required to install some pip pkgs
          - "{{ item }}-dev"
          - "{{ item }}-virtualenv"
        state: latest
        install_recommends: no
        update_cache: yes
        cache_valid_time: 3600
      loop:
        - python
        - python3

      # separate task because pkgs there use a different naming scheme
    - name: install additional python versions from deadsnakes
      apt:
        name:
          - "{{ item }}"
          - "{{ item }}-dev"
          - "{{ item }}-venv"
        state: latest
        install_recommends: no
        update_cache: yes
        cache_valid_time: 3600
      loop:
        - python3.7

      # unfortunately pip needs to be installed with
      # python3.7 -m pip install pip
      # and then
      # pip3.7 install --upgrade pip

      # TODO: check if they are really needed, install with pip
    - name: install python apt packages
      apt:
        name:
          - python-numpy
          - python-scipy
          - python-matplotlib
          - python-tk

    - name: Install pip packages
      pip:
        name: termtosvg   # recording terminal sessions
        executable: pip3