Module 14 of 15 · Step 1 of 15

Mixed Practice

Real programs use several beginner ideas at once. Work one step at a time: inspect the data, decide what must repeat, decide what must be tested, and choose what to return or display.

By the end of this lesson, you can:

Combine loops and conditions
Calculate an average
Filter list values
Read dictionaries in a loop
Build a small reusable function

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Learn · Plan the data and result

Concept 1 of 6

Plan the data and result

Before coding, write down the input, the desired output, and the operation that connects them. A short plan prevents random edits when a task combines several concepts.

Pattern

# input -> process -> output

Code

scores = [6, 8, 10]
average = sum(scores) / len(scores)
print(average)

Output

8.0

Why it works

The list is the input.
sum gives 24 and len gives 3.
Dividing produces the average 8.0.

Common mistake

Not this

sum(scores) / 0

Try this

sum(scores) / len(scores)

Divide by the number of items, not by zero or a guessed count.