► Overview

Return values allow functions to send data back to the caller. Scope determines where variables can be accessed in your code. Understanding both is crucial for writing effective functions.

► Real-World Analogy

Think of a calculator:
» Input: Numbers and operation
» Process: Perform calculation
» Return: The result
» The result goes back to whoever used the calculator

► Key Concepts

✓ return statement: Sends value back to caller
✓ Functions can return any data type
✓ return ends function execution
✓ Multiple return statements possible
✓ None returned if no return statement
✓ Local scope: Variables inside function
✓ Global scope: Variables outside function

■ Return Examples

/code

Return single value

def square(x):
return x * x

result = square(5)
print(result)

Return multiple values

def get_name():
return “John”, “Doe”

first, last = get_name()
print(f”{first} {last}”)

Early return

def check_age(age):
if age < 18:
return “Minor”
return “Adult”

print(check_age(15))

Output:
25
John Doe
Minor

► Important Points

✓ return immediately exits the function
✓ Can return multiple values as tuple
✓ Local variables exist only in function scope
✓ Global variables accessible everywhere
✓ Avoid modifying global variables in functions
✓ Use return for function output

► Remember

✓ Every function returns something (None if not specified)
✓ return stops function execution immediately
✓ Variables created in functions are local
✓ Use return to send results back to caller
✓ Global keyword needed to modify global variables

■ Practice Challenge

1. Create a function that returns both quotient and remainder
2. Write a function with multiple return points based on conditions
3. Build a function that returns maximum of three numbers