Organize code with functions.

Define Function

```python def greet(): print("Hello from Los Angeles!")

Call function greet() ```

Function with Parameters

```python def greet_person(name): print(f"Hello {name}!")

greet_person("Emma") # Hello Emma! greet_person("Jack") # Hello Jack! ```

Return Values

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

result = add(5, 3) print(result) # 8 ```

Default Parameters

```python def greet(name, city="Chicago"): print(f"Hello {name} from {city}!")

greet("Tom") # Hello Tom from Chicago! greet("Sarah", "Miami") # Hello Sarah from Miami! ```

Multiple Return Values

```python def get_user(): name = "David" age = 30 return name, age

user_name, user_age = get_user() print(user_name) # David ```

Remember

- Functions make code reusable - Use descriptive function names - Return data with return statement