What is the purpose of nested lists in Python?

Nested lists refer to the situation where one list contains other lists. The main purposes of nested lists are as follows:

1. Store multi-dimensional data: Nested lists can be used to store multi-dimensional data, such as 2D tables or multi-dimensional matrices. Each internal list represents a row or column of data.
2. Hierarchical relationship can be represented using nested lists. For example, a company’s organizational structure can be represented using a nested list, where each inner list represents a department, and the elements within the inner list represent the employees of that department.
3. Handling complex data structures: Nested lists can be used to handle complex data structures. For example, a nested list can represent a tree, where each inner list represents a node and the elements within the inner list represent the node’s children.
4. Nested lists can be used to implement multi-level indexing, such as in a student information system where each element in the outer list represents a student, and the elements in the inner list represent that student’s information (such as name, age, grades, etc.).

In conclusion, nested lists in Python are versatile and multipurpose, and can be used to handle and represent various complex data structures and relationships.