Python for non-programmers, lesson 12: Functions

Learn how to define and use functions in Python — a key building block for writing better, more reusable code.

Want to teach the computer to do something new? You want to define a function. Not surprisingly defining functions is one of the most common things that programmers do. In this video, I introduce the idea of functions, how to define them, how to invoke them, and how to get results ("return values") back from them.

-----

Homework exercises for this lesson:

1. Write a function, maxnum, that takes a single argument, a list of numbers. It returns the largest number in that list. (Do not use the built-in max function to do this!)

2. Write a function, lastword, that takes a list of words. It returns the word in that list that occurs last, alphabetically.

3. Write a function, charcount, that takes a string and returns a dict. The dict’s keys will be all of the different characters that occur in the string, and its values will be the number of times that each character appeared.

[ReuvenLerner]

🤔 What do you think about functions?

👇 Have questions about defining or calling? Drop them in the comments — I read them all.

📝 Want the course notebooks and practice materials?