Sets

Sets are basically unordered lists.

To create a set, you use the set() function or enclose one or more comma-separated
values in curly brackets. The same function will transform another data structure into a set.

empty_set = set()
my_set = {'a', 'b', 12, True, [1,2,3]}

You might expect {} to create an empty set. But {} creates an empty dictionary. Why? Dictionaries were in Python first and took possession of the curly brackets.

Now we should you use a set in practice? Probably to take advantage of set functions like union and intersection. Here is an example

numbers = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
even_numbers = {0, 2, 4, 6, 8}
nums_intersect = numbers.intersection(even_numbers) 
nums_union = numbers.union(even_numbers)