Functions

Define a function with def name(parameters):, followed by an indented block, and return a value if it should produce one.

Example: a function using an f-string

def greet(name):
    return f"Hello, {name}!"

print(greet("Chidi"))

Hello, Chidi!

The f before the opening quote makes it an f-string — anything inside curly braces gets evaluated and inserted directly into the string. This is the standard, readable way to build strings containing variables in modern Python, and is generally preferred over older approaches like manually joining strings with +.