Tuple object actually immutable. Tuple is a collection of *pointers!* on objects, if object is mutable, we can modify this object.
a = (1,2, [3,4,5], 6)
# Equivalent:
b = [3,4,5]
a = (1, 2, b, 6)
# Object [3,4,5] is mutable, we can change himself.
b[0] = 'test'
print(a) # -> (1,2, ['test', 4, 5], 6)
@АлексейАлекс-г8ь