Functions Introduction

Python Functions

Functions are reusable blocks of code defined with def.

Defining Functions

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

print(greet("Alice"))

Default Parameters

def power(base, exp=2):
    return base ** exp

print(power(3))    # 9
print(power(2, 8)) # 256

*args and **kwargs

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

def info(**kwargs):
    for k, v in kwargs.items():
        print(f"{k}: {v}")

add(1, 2, 3, 4)
info(name="Alice", age=30)

Pro Tip

Default arguments are evaluated once at function definition — avoid mutable defaults like lists.

Related Resources

Python Reference

Complete tag & property list

Python How-To Guides

Step-by-step practical guides

Python Exercises

Practice what you've learned