Return Values

Getting a result back from a function using return — the difference between a function that does something and one that produces something.

"print() shows a value on screen. return sends the value back to whoever called the function — so they can use it, store it, or pass it somewhere else."

— ShurAI

print vs return — The Key Difference

This is the most important concept in this lesson. Both look similar but they do very different things:

print()

Displays the value on screen.
The function gives nothing back.
Cannot store the result.

Like a chef who cooks AND eats the food.

return

Sends the value back to the caller.
The caller decides what to do with it.
Can be stored, calculated, passed on.

Like a chef who cooks and hands it to you.

python — print vs return side by side

# Version 1 — uses print (result is LOST)
def add_print(a, b):
    print(a + b)           # shown on screen, gone

result = add_print(3, 4)   # prints 7
print(result)              # None — nothing was returned!

# Version 2 — uses return (result is USABLE)
def add_return(a, b):
    return a + b

result = add_return(3, 4)  # result = 7
print(result)              # 7
print(result * 2)          # 14 — can use it!

How return Works

When Python hits a return statement, it immediately exits the function and sends the value back to where the function was called:

python

def square(n):
    return n * n
    print("This line NEVER runs!")  # after return = unreachable

x = square(5)         # x = 25
y = square(3)         # y = 9
print(x + y)           # 34

# Returned value used directly in an expression
print(square(4) + square(3))   # 25

Returning Multiple Values

Python functions can return multiple values at once as a tuple. Unpack them directly into variables:

python

def min_max(numbers):
    """Return both the smallest and largest number."""
    return min(numbers), max(numbers)

scores = [72, 45, 91, 66, 88]

# Unpack the two returned values
lowest, highest = min_max(scores)
print(f"Lowest : {lowest}")    # 45
print(f"Highest: {highest}")   # 91

Early Return — Exit When Done

return can be used to exit a function early, just like break exits a loop. Great for guard clauses:

python

def divide(a, b):
    if b == 0:
        return "Error: cannot divide by zero"   # early exit
    return a / b

print(divide(10, 2))    # 5.0
print(divide(10, 0))    # Error: cannot divide by zero

Real Example — Shopping Discount Calculator

python

def get_discount(total):
    """Return the discount percentage based on cart total."""
    if total >= 2000:
        return 20
    elif total >= 1000:
        return 10
    elif total >= 500:
        return 5
    else:
        return 0

def checkout(name, cart_total):
    """Print the full checkout summary."""
    discount_pct = get_discount(cart_total)         # calling another function
    discount_amt = cart_total * discount_pct / 100
    final        = cart_total - discount_amt
    print(f"\n{'='*35}")
    print(f"  Customer : {name}")
    print(f"  Cart     : Rs.{cart_total}")
    print(f"  Discount : {discount_pct}% (-Rs.{discount_amt:.0f})")
    print(f"  YOU PAY  : Rs.{final:.0f}")
    print(f"{'='*35}")
    return final

checkout("Riya",   350)
checkout("Arjun",  1250)
checkout("Sneha",  2400)

output

===================================
  Customer : Riya
  Cart     : Rs.350
  Discount : 0% (-Rs.0)
  YOU PAY  : Rs.350
===================================

===================================
  Customer : Arjun
  Cart     : Rs.1250
  Discount : 10% (-Rs.125)
  YOU PAY  : Rs.1125
===================================

===================================
  Customer : Sneha
  Cart     : Rs.2400
  Discount : 20% (-Rs.480)
  YOU PAY  : Rs.1920
===================================

"A function that only prints is a dead end. A function that returns gives you a result you can use, chain, and build on."

— ShurAI

🧠 Quiz — Q1

What does return do in a function?

🧠 Quiz — Q2

What does a function return if there is no return statement?

🧠 Quiz — Q3

What happens to code written after a return statement?

🧠 Quiz — Q4

Given def add(a,b): return a+b — what does result = add(3, 4) store in result?