(Python Study) list, set, tuple type casting

#can change freely
a = set((1,2,3))
b = list(a)
c = tuple(b)
d = set(c)


>>> a
set([1, 2, 3])
>>> b
[1, 2, 3]
>>> d
set([1, 2, 3])
>>> c
(1, 2, 3)
>>>