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!