Data model
- Python course
- Beginner
- Lesson 113/116
- 6 min
Set up the data model and collections.
Data model: add a new grade
In this lesson you will add a new grade to the grades list with append. append puts an item at the end of the list and grows it:
grades.append(95)
print(len(grades)) # 4The starting code includes the previous lesson's solution — grades = [85, 90, 78] and print(grades) are ready. You will add the append call and new output.
This shows the list growing dynamically.
Practice Add a new grade and print the count
Write grades.append(95). Then write print("eklendi:", len(grades)).
Starter code
# Grade calculator - grades list
grades = [85, 90, 78]
print(grades)
# add a new grade and print the countSample solution
grades = [85, 90, 78]
print(grades)
grades.append(95)
print("eklendi:", len(grades))Expected output
[85, 90, 78] eklendi: 4
Next step: business logic
The data model is ready — you can now dynamically add grades to the list. In the next lesson you will add a business logic layer: computing the average with sum and len.
This layer will turn raw data into a meaningful result. The average is a fundamental statistic that summarises the grades. The starting code carries the previous solution; you only add the calculation.
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Match the data model
| Term | Meaning |
|---|---|
append |
Adds to end |
len(grades) |
Item count |
[85, 90, 78] |
Three-grade list |
95 |
New grade |
2 What does grades.append(95) do?
- Puts 95 at the start
- Removes 95
- Adds 95 at the end Correct answer
- Empties the list
Explanation: append always adds the item at the end of the list.
3 Complete the append call
grades.____(95)grades.append(95)Explanation: grades.append(95) adds 95 to the list.