Python Sets

Sets are unordered collection of data items. They store multiple items in a single variable. Set items are separated by commas and enclosed within curly brackets {}. Sets are unchangeable, meaning you cannot change items of the set once created. Sets do not contain duplicate items.

Example:

info = {"Carla", 19, False, 5.9, 19}
print(info)

Output:

{False, 19, 5.9, 'Carla'}

Here we see that the items of set occur in random order and hence they cannot be accessed using index numbers. Also sets do not allow duplicate values.

Quick Quiz: Try to create an empty set. Check using the type() function whether the type of your variable is a set

Accessing set items:

Using a For loop

You can access items of set using a for loop.

Example:

info = {"Carla", 19, False, 5.9}
for item in info:
    print(item)

Output:

False
Carla
19
5.9

Practice

s = {2, 4, 2, 6}
print(s)

info = {"Carla", 19, False, 5.9, 19}
print(info)

harry = set()
print(type(harry))

for value in info:
  print(value)

Output:

{2, 4, 6}
{False, 19, 5.9, 'Carla'}
<class 'set'>
False
19
5.9
Carla

Explanation

• s = {2, 4, 2, 6}

  • Creates a set named s.

  • Duplicate values are automatically removed because sets store only unique elements.

• print(s)

  • Displays the contents of the set.

• info = {"Carla", 19, False, 5.9, 19}

  • Creates a set containing different data types.

  • Duplicate values are removed automatically.

• print(info)

  • Displays all elements of the set.

• harry = set()

  • Creates an empty set.

  • set() is used because {} creates an empty dictionary.

• print(type(harry))

  • Shows the data type of the variable harry.

• for value in info:

  • Iterates through each element in the set info.

• print(value)

  • Prints each element one by one during the loop.

Key Points

• Sets store only unique values.

• Duplicate elements are automatically removed.

• Sets are unordered collections.

• Sets can contain elements of different data types.

• Use set() to create an empty set.