← Python Coding Track

Module 02FoundationWeeks 1–2

Control Flow

01

Learning outcomes

  • Write conditional statements
  • Understand decision-making in code
02

Core concepts

if / elif / elseComparison operatorsLogical operators (and, or, not)
03

Lessons

Module goal

Learner understands how programs make decisions, and can write code that behaves differently depending on the situation.

Lesson 1 of 5 · lecture

Why programs need to make decisions

Step 1 of 2

So far every script runs the exact same way, top to bottom, every time. Real software doesn't. A login screen behaves differently depending on whether the password is correct. A repair-tracking app behaves differently depending on whether a device is in stock. That is control flow: the program checks a condition and, depending on True or False, takes a different path.

Human analogy

“If it's raining, take an umbrella. Otherwise, don't.” Python's if statement works on exactly this logic.

04

Guided labs

Lab part 1 — age checker

  1. 1.Create control_flow.py
  2. 2.Ask for the user's age with input() — note input() always returns a string, so convert with int()
  3. 3.Use if/elif/else to print teenager (13–19), adult (20–64) or senior (65+)
age = int(input("Enter your age: "))

if age >= 65:
    print("You are a senior.")
elif age >= 20:
    print("You are an adult.")
elif age >= 13:
    print("You are a teenager.")
else:
    print("You are a child.")

Lab part 2 — simple login checker

  1. 1.Hardcode a correct username and password
  2. 2.Ask the user to input a username and password
  3. 3.Use and to check both match before granting access
correct_username = "nextdoortech"
correct_password = "1234"

entered_username = input("Enter username: ")
entered_password = input("Enter password: ")

if entered_username == correct_username and entered_password == correct_password:
    print("Access granted.")
else:
    print("Access denied.")

Success criteria

Both scripts run without errors and branch correctly — test each several times with different values to see the branching in action.

05

Knowledge Check

Question 1 of 6

What's the key difference between = and ==?

06

What you read

  • How programs branch based on conditions
  • Comparison operators (==, !=, >, <)
  • Combining conditions with logical operators
07

What you understand

Key takeaways

  • — Control flow lets code react to different inputs
  • — Real programs are not purely linear
08

Hands-on lab

Lab tasks

  1. 1.Build an age-checker (teen/adult/senior)
  2. 2.Build a simple login checker (username + password match)
09

Knowledge check

  • Predict which branch executes given a scenario
  • Write if-elif-else blocks

Write your answers in your own notes before moving on — explaining a concept in your own words is the fastest way to find the gaps.

10

Mark progress