List-of-lists

Definition

A list-of-lists is a nested list where each element of the main list is itself a list. This structure allows for the creation of multi-dimensional arrays in Python.

5 Must Know Facts For Your Next Test

1. A list-of-lists can be used to represent matrices, grids, or tables in Python.
2. Accessing elements in a list-of-lists requires multiple indexing operations.
3. List comprehensions can be used to flatten a list-of-lists into a single list.
4. Iterating through a list-of-lists often involves nested loops.
5. Modifying an element within a nested list requires specifying both the main and sublist indices.

Review Questions

• How do you access the element at the second row and third column in a 2D list?
• What Python feature allows you to convert a nested list into a flat list?
• Explain how you would iterate through all elements of a nested list using loops.

Related terms

List Comprehension: A concise way to create lists in Python using a single line of code with an expression and for loop inside square brackets.

Indexing: The process of accessing individual elements within an array or list using their position number.

Multi-dimensional Array: An array containing more than one row or column, often implemented as lists-of-lists in Python.