Functions

A function is a reusable block of code. Define it with def.

def greet():
    print("Hello!")

greet()   # call the function

Parameters

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

greet("Ana")

Return

return gives back a value:

def add(a, b):
    return a + b

result = add(2, 3)   # 5

Default value

def greet(name="guest"):
    print(f"Hello, {name}!")

greet()         # Hello, guest!
greet("Ana")    # Hello, Ana!

Many arguments

def add(*numbers):
    return sum(numbers)

print(add(1, 2, 3, 4))   # 10

Keyword arguments

def info(name, age):
    print(name, age)

info(age=30, name="Ana")