8.6. Sequence Unordered
8.6.1. Both
unordered
impossible to getitem and slice
unique elements
only hashable elements
8.6.2. Frozenset
immutable
8.6.3. Set
mutable
8.6.4. Memory Footprint
>>> from sys import getsizeof
>>>
>>>
>>> a = {1, 2, 3}
>>> b = frozenset({1, 2, 3})
>>>
>>> getsizeof(a)
216
>>>
>>> getsizeof(b)
216