Iterator [Python] __iter__(), __next__()

# Python 3 : Iterator

b = {1, 2, 3}

b_iter = b.__iter__()

print(type(b_iter)) # <class 'set_iterator'>

print(b_iter.__next__()) # 1

print(b_iter.__next__()) # 2

print(b_iter.__next__()) # 3

print(b_iter.__next__()) # StopIteration