Python Basics · Final Project · Lesson 35 of 36
Building and Testing
Concept
Building and Testing
Combine variables, functions, loops, and data structures from this course into one working program.
Try your program with an empty list, a single item, and a large list — these edge cases catch a surprising number of bugs that "normal" test inputs miss.
By the end of this lesson
- Explain the core idea behind Building and Testing.
- Predict output before running a change.
- Test one realistic and one unusual input.
- Use the result to make the next decision.
How to study this page
- 1. Read one concept.
- 2. Change the example.
- 3. Run, compare, and explain.
- 4. Complete the challenge below.
ExampleRunnable
def average(scores):
return sum(scores) / len(scores)
print(average([80, 90, 100]))Self-check before continuing
Without looking at the example, describe what changes when you modify one input in Building and Testing. Then reopen the editor and prove your explanation with a small test.
You are ready to continue when you can predict, test, and explain the result.
Your turn
Extend the average function to also print a pass/fail message.
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Console