15.1. The Need for Lists

Up until now, most of the data we have worked with we have thought about as single values: The number 34.2, or the word “Hello”, or a Turtle, or an Image. We have used multiple pieces of data in programs - we might work with a first and last name, or an hours_worked and pay_rate - but those pieces of data were usually given separate names.

Often times however, we want to work with a group of values that are all related. Say I want to work with the scores a student has gotten on a series of eight quizzes. If I name each score separately (quiz1, quiz2, …) it will be hard to write code that does something like find the highest score. I would end up having to do like this:

highest_score = quiz1
if quiz2 > highest_score:
    highest_score = quiz2
if quiz3 > highest_score:
    highest_score = quiz3
if quiz4 > highest_score:
    highest_score = quiz4

Remember that in programming, we want to avoid writing the same code over and over. And that is what this is… I am doing the same steps over and over, just with the different variables. What I need is a way to lump all the quizzes together so I can talk about them all at once and more easily write code to work with all the individual scores.

You have attempted of activities on this page