Python lesson

Functions, step 2

profit(140, 90) works out 140 - 90 and hands back 50, which is stored in p. A function can take more than one input: separate them with commas.

About 5–10 minutes · no sign-up needed

Example

return sends a value back to wherever the function was called, so you can store it or use it:

def profit(revenue, cost):
    return revenue - cost

p = profit(140, 90)
print(p)
print(profit(70, 45))

Output:

50
25

returnSends a value back to where the function was called.

p = profit(140, 90)Store what comes back, or use it straight away.

print vs returnprint only shows a value. return hands it back so you can use it.

Put together: def profit(revenue, cost): then, indented, return revenue - cost.

Try each one in your head first, then open the answer.

1. Build the line that sends back the VAT: amount times 0.075.

return amount * 0.075

2. Build a line that stores the result of profit(140, 90) in p.

p = profit(140, 90)

3. Write a function called double that returns a number times 2. Then print double(21).

def double(n):
    return n * 2
print(double(21))

4. Write a function margin(revenue, cost) that returns revenue minus cost. Then print margin(140, 90).

def margin(revenue, cost):
    return revenue - cost
print(margin(140, 90))

5. Write a function label(revenue) that returns "Big" if revenue is over 50, otherwise "Small". Then print label(70).

def label(revenue):
    if revenue > 50:
        return "Big"
    return "Small"
print(label(70))

Learn it by doing. This lesson is a short hands-on level on Bampaa: see it work, then build and write it yourself, with instant feedback.

About 5–10 minutes · no sign-up needed