Track 5 · Lesson 8 of 12

Decomposition: building programs from functions

Break a problem into small functions that each do one job, combine them, and organise the program around a main() function.

You will be able to

• Break a task into steps and give each step its own function
• Write functions that call other functions and pass results between them
• Organise a program with a main() function and the if __name__ == "__main__": guard
• Refactor a long block of code into smaller, testable functions without changing its behaviour