Conclusion: Creating Functions
What We Learned in This Chapter
Functions are the building blocks of Python programs. They allow you to:
- Organize your code
- Reuse logic
- Make your programs cleaner and more readable
Summary of Key Concepts
| Lesson | What You Learned |
|---|---|
| 8.1 - Introduction | Why functions matter and how they help organize code |
| 8.2 - Intro to Functions | Writing simple functions using def |
| 8.3 - Simplifying Code | How to avoid repetition using functions |
| 8.4 - Combining Lists and Functions | Using functions with lists to perform reusable actions |
| 8.5 - Parameters and Defaults | Making functions flexible with parameters and default values |
| 8.6 - Positional & Keyword Args | Advanced ways to pass arguments to functions |
| 8.7 - Return Values | Getting outputs from functions using the return keyword |
Why Functions Matter
Functions make your code:
- Modular – Break big problems into smaller parts
- Clean – Reduce repetition and clutter
- Testable – Each function can be tested individually
- Reusable – You write once, and use many times
Example: Before and After
Without Functions
print(10 * 5)
print(20 * 5)
print(30 * 5)With a Function
def multiply_by_five(n):
return n * 5
print(multiply_by_five(10))
print(multiply_by_five(20))
print(multiply_by_five(30))Cleaner, reusable, and easy to update later!
What You Should Practice
- Write your own small functions for math, strings, or lists.
- Practice using both parameters and return values.
- Test passing values in different ways: positionally and with keywords.