–Based on http://www.velocityreviews.com/forums/t339699-are-tuple-really-immutable.html —
t = (,)
# apply the id() function to each item in t
([1, 0], )
map(id,t) # unchanged
So tuple deviates from java immutability, which mandates t returning a clone — essentially copy-on-write.
A tuple is like an ordered club roster written with indelible ink. The members of the club may change jobs, age, salary etc but the roster remains the same: same members, same SSN like python id(), same ranking.
In C++ lingo, the “t” tuple has 2 pointers on its real estate. It qualifies as immutable since the two 32-bit fields remain _bit_wise_constant_. The pointees live outside the tuple’s real estate and are Editable.