Free course · Lesson 2 of 5

Control Flow: Conditions & Loops

In this lesson you will

Choose between actions with if/elif/else
Repeat work with for loops

Programs make decisions with if / elif / else, and repeat work with for and while loops. Mastering these two tools lets you process any amount of data without writing repetitive code.

for item in collection: loops over a list, string, or range directly.
while condition: repeats until a condition becomes false.
Comparison operators (==, !=, >, <) and boolean operators (and, or, not) build conditions.
break exits a loop early; continue skips to the next iteration.

💡 Practical Skill: Loops and conditions are the backbone of every automation script — from validating a batch of registration forms to generating a weekly attendance summary.

Worked exampleAttendance Threshold Check

Python

attendance = [18, 15, 20, 9, 17, 12, 20]  # classes attended out of 20total_classes = 20 for i, classes_attended in enumerate(attendance, start=1):    rate = classes_attended / total_classes * 100    if rate >= 80:        status = "Eligible for certificate"    elif rate >= 60:        status = "Needs make-up session"    else:        status = "At risk — contact student"    print(f"Student {i}: {rate:.0f}% attendance — {status}")

Practice exercise

Given the attendance list in the example, print how many learners are eligible for a certificate.

Key takeaways

Conditions are checked top to bottom; the first True branch runs
Loops process every item in a list without repeating code
Always test boundary values such as 59, 60 and 80

In the full program Module 2: Decisions and Loops See how this topic is taught in depth, with practical activities and an assessment.

Free self-study lesson — no certificate. For the full instructor-led program, see registration options.