> can be any of latin-1, UCS-2 or UCS-4, as described in PEP 393

My bad, I haven't seriously used Python for over 15 years now, so I stand corrected (and will clarify the post).

My main point stands though, Python strings have an internal representation, but it's not exposed to the user like Ruby strings.

> Article also says PHP has immutable strings. They are mutable, although often copied.

Same. Thank you for the correction, I'll update the post.