Learn

We’ve seen that the items in a list can be numbers or strings. Lists can contain other lists! We will commonly refer to these as two-dimensional (2D) lists.

Once more, let’s look at a class height example:

• Noelle is 61 inches tall
• Ava is 70 inches tall
• Sam is 67 inches tall
• Mia is 64 inches tall

Previously, we saw that we could create a list representing both Noelle’s name and height:

``noelle = ["Noelle", 61]``

We can put several of these lists into one list, such that each entry in the list represents a student and their height:

``heights = [["Noelle", 61], ["Ava", 70], ["Sam", 67], ["Mia", 64]]``

We will often find that a two-dimensional list is a very good structure for representing grids such as games like tic-tac-toe.

``````#A 2d list with three lists in each of the indices.
tic_tac_toe = [
["X","O","X"],
["O","X","O"],
["O","O","X"]
]``````

Let’s practice creating our own 2D list!

### Instructions

1.

A new student named `"Vik"` has joined our class. Vik is `68` inches tall. Add a sublist to the end of the `heights` list that represents Vik and his height.

2.

Create a two-dimensional list called `ages` where each sublist contains a student’s name and their age. Use the following data:

• `"Aaron"` is `15`
• `"Dhruti"` is `16`