Python Set

Set is an unordered and unindexed collection of values or elements which do not allow duplicate values and are placed within the curly braces.

Example


names = {"Jonny", "Danny", "Kelly", "Jane"}
print(names)

Output

{"Jane", "Jonny", "Kelly", "Danny"}

Loop Through Set

To access the items or elements of a set, you can use the for loop.

Example


names = {"Jonny", "Danny", "Kelly", "Jane"}
for i in names:
    print(i)

Output

Danny
Jane
Jonny
Kelly

Add Items in set

To add items in a Set, you can use the add() method.

Example


names = {"Jonny", "Danny", "Kelly", "Jane"}
names.add("Peter")
print(names)

Output

{"Jonny", "Kelly", "Peter", "Danny", "Jane"}

Update Items in set

The update() method adds items from one set in a Set.

Example


fruits = {"apple", "banana", "mango", "grapes"}
fruits.update({"watermelon", "guava", "cherry"})
print(fruits)

Output

{'cherry', 'apple', 'watermelon', 'guava', 'grapes', 'mango', 'banana'}

The set() constructor

The set() constructor is used to create a new set.

Example


foods = (("bread", "butter", "milk", "egg"))
print(foods)

Output

('bread', 'butter', 'milk', 'egg')

Length of Set

You can use the len() function to get the the number of items present in a set.

Example


foods = {"bread", "butter", "milk", "egg"}
print(len(foods))

Output

Remove Item from a set

The remove() function removes item from a set.

Example


foods = {"bread", "butter", "milk", "egg"}
foods.remove("butter")
print(foods)

Output

{'milk', 'egg', 'bread'}

Discard Item from a set

The discard() function also removes the specified item from a set.

Example


foods = {"bread", "butter", "milk", "egg"}
foods.discard("milk")
print(foods)

Output

{'egg', 'butter', 'bread'}

Pop Item

The pop() function also removes the last item from a set. Since, a set items are unordered, so you cannot determined which item will get removed. The pop() functions returns the removed item .

Example


foods = {"bread", "butter", "milk", "egg"}
x = foods.pop()
print(x)

Delete set

The del keyword deletes the set.

Example


foods = {"bread", "butter", "milk", "egg"}
del foods
print(foods)

Output

NameError: name 'foods' is not defined

Clear set items

The clear() method empties items from a set.

Example


foods = {"bread", "butter", "milk", "egg"}
foods.clear()
print(foods)

Output

set()

Join two sets

The union() method and update() method combines all items of sets.

Example


set1 = {"bread", "butter", "milk", "egg"}
set2 = {"fish", "meat"}
set3 = set1.union(set2)
print(set3)

Output

{'butter', 'meat', 'bread', 'egg', 'fish', 'milk'}

The update() method inserts items from set2 to set1.

Example


set1 = {"bread", "butter", "milk", "egg"}
set2 = {"fish", "meat"}
set1.update(set2)
print(set1)

Output

{'meat', 'bread', 'milk', 'butter', 'egg', 'fish'}

Check If an Item Exists

You can use the in keyword to check if an item exists in a set.

Example


foods = {"bread", "butter", "milk", "egg"}
if "butter" in foods:
    print("butter exist")

Output

butter exist