defaults/main.yml

@@ -1,5 +1,14 @@
 ---
-python3_packages:
-  - python3
-  - python3-pip
+# @var python3_packages:description: >
+# The default packages depend on the OS version. For RHEL7 based systems, Python3.8 from
+# SCL `centos-sclo-rh`. Therefore, the SCL need to be installed and enabled already!
+# For RHEL8 based system Python3.9 will be installed from the Appstream repo.
+# @var python3_packages:default: "_unset_"
+
 python3_packages_extra: []
+
+# @var python3_packages_remove:description: Optional list of old Pathon packages that should be removed.
+python3_packages_remove: []
+
+python3_link_bin: []
+python3_link_bin_path: /usr/bin

molecule/centos7/converge.yml

@@ -1,5 +1,9 @@
 ---
 - name: Converge
   hosts: all
+  vars:
+    python3_packages_extra:
+      - centos-release-scl
+
   roles:
     - role: xoxys.python3

tasks/main.yml

@@ -1,2 +1,15 @@
 ---
+- include_vars: "{{ var_files }}"
+  vars:
+    var_files: "{{ lookup('first_found', params, errors='ignore') }}"
+    params:
+      files:
+        - "{{ ansible_lsb.id | default('') | lower }}.yml"
+        - "{{ ansible_os_family | lower }}-{{ ansible_distribution_major_version }}.yml"
+        - "{{ ansible_os_family | lower }}.yml"
+      paths:
+        - "vars"
+  when: var_files
+
+- include_tasks: overwrites.yml
 - include_tasks: setup.yml

tasks/overwrites.yml

@@ -0,0 +1,5 @@
+---
+- name: Define python3_packages
+  set_fact:
+    python3_packages: "{{ __python3_packages | list }}"
+  when: python3_packages is not defined

tasks/setup.yml

@@ -6,16 +6,20 @@
         state: present
       loop: "{{ python3_packages_extra + python3_packages }}"
 
-    - name: Link binaries to '{{ __python3_link_bin_path }}'
+    - name: Remove other Python pckages
+      package:
+        name: "{{ item }}"
+        state: absent
+      loop: "{{ python3_packages_remove }}"
+
+    - name: Link binaries to '{{ python3_link_bin_path }}'
       file:
         src: "{{ item.src }}"
-        dest: "{{ __python3_link_bin_path }}/{{ item.dest }}"
+        dest: "{{ python3_link_bin_path }}/{{ item.dest }}"
         state: link
         force: yes
-      loop:
-        - { src: /usr/bin/python3.6, dest: python3 }
-        - { src: /usr/bin/pip3.6, dest: pip3 }
+      loop: "{{ python3_link_bin }}"
       loop_control:
-        label: "{{ __python3_link_bin_path }}/{{ item.dest }}"
+        label: "{{ python3_link_bin_path }}/{{ item.dest }}"
   become: True
   become_user: root

vars/main.yml

@@ -1,2 +0,0 @@
----
-__python3_link_bin_path: /usr/bin

vars/redhat-7.yml

@@ -0,0 +1,4 @@
+---
+__python3_packages:
+  - rh-python38
+  - rh-python38-python-pip

vars/redhat-8.yml

@@ -0,0 +1,4 @@
+---
+__python3_packages:
+  - python39
+  - python39-pip