All you know about Sets in Python-Part 1

In Python, a Set is an unordered collection of unique data items. In other words, Python Set is a collection of elements (Or objects) that contains no duplicate elements.

Unlike List, Python Set doesn’t maintain the order of elements, i.e., It is an unordered data set. So you cannot access elements by their index or perform insert operation using an index number.

🔸A set is a collection of unique elements.

🔸The elements (items) in a set must be of an immutable type.

🔸Any immutable data type can be an element of a set (e.g. strings and integers). If you try to use a mutable data type inside a set, an exception (TypeError) is raised, as shown below.

set1 = {[1,2]}


Error : 
TypeError: unhashable type: 'list'

🔸 Immutable types include:

• Numbers (e.g., integers, floats)
• Strings
• Tuples (if all elements in the tuple are also immutable)

🔸 Mutable types (e.g., lists, dictionaries, sets) cannot be elements of a set.

Why can’t a set add mutable types?

• Sets use a hash table internally to store elements. Immutable objects have a fixed hash value, which is required for efficient storage and retrieval in a…