Why does Django use tuples for settings and not lists?

Question

Quoting this answer:

Apart from tuples being immutable there is also a semantic distinction that should guide their usage. Tuples are heterogeneous data str

Answer 1

This was changed in Django 1.9:

Default settings that were tuples are now lists

The default settings in django.conf.global_settings were a combination of lists and tuples. All settings that were formerly tuples are now lists.

https://docs.djangoproject.com/en/1.9/releases/1.9/#default-settings-that-were-tuples-are-now-lists