1 · Understand
for loops and range(). Study the code and predict what it does before running it. Change a value or string and observe how the output changes.
for number in range(1, 6):
print(number)Python Foundations · Lesson 6 of 12
Count-controlled loops
for loops and range(). Learn through short examples, practical tasks and targeted questions.
Repeating with for and range
A count-controlled loop is useful when you know how many repetitions are needed. range() creates a sequence of integers; its stop value is not included. Trace the loop variable for each iteration and predict exactly how many outputs appear.
Watch out: range(5) produces 0, 1, 2, 3, 4—not 1 through 5. This is a common off-by-one error.
2 · Practise
Print the seven-times table from 7 × 1 to 7 × 12.
Plan your inputs, processing and outputs. Write the code in Mu, IDLE or PyCharm; test at least three cases.
Show a reference solution after attempting the task
for n in range(1, 13):
print("7 x", n, "=", 7 * n)3 · Debug the code
Identify the problem and explain how to fix it before revealing the answer.
for x in range(5)
print(x)Reveal the corrected program and explanation
for x in range(5):
print(x)Compare the two snippets. Identify the changed line, run the corrected version and explain the effect.
4 · Check your understanding
5 · Challenge and reflect
Extension: Improve your solution to deal with unexpected input, add a second feature or display results more clearly.
Reflect: What was the hardest part? What would you test if someone else used your program?
Want extra practice? Try interactive Python tracing and debugging questions →