Add Items
Once a set is created, you cannot change its items, but you can add new items.
To add one item to a set use the add() method.
add()Add Sets
To add items from another set into the current set, use the update() method.
tropicalAdd Any Iterable
The object in the update() method does not have to be a set, it can be any iterable object (tuples, lists, dictionaries etc.).
Example
thisset = {"apple", "banana", "cherry"}
mylist = ["kiwi", "orange"]
thisset.update(mylist)
print(thisset)