Build a Discount Calculator

Python
1

I’m struggling with this one a little as well. My code technically meets each objective, since I can get each of the price & discount values calculated as designed, though when I input a string for either, that’s the only part that doesn’t pass the required objectives, though it does say “This should be a number” for each, but it also returns “None” afterward as well. I have looked through this thread and a couple others and I’m wondering if this leeson specifically wants us to use “type()” instead of “isinstance()” since I don’t believe we’ve learned that in the course yet.

Here’s my code:

def apply_discount(price,discount):
    if not (isinstance(price, int) or isinstance(price, float)):
        print("The price should be a number")
    elif not (isinstance(discount, int) or isinstance(discount, float)):
        print("The discount should be a number")
    elif price <= 0:
        print("The price should be greater than 0")
    elif discount < 0 or discount > 100:
        print("The discount should be between 0 and 100")
    else:
        return (price - (price * (discount / 100)))




print(apply_discount(100, 20))
print(apply_discount(200, 50))
print(apply_discount(50, 0))
print(apply_discount(100,100))
print(apply_discount(74.5, 20.0))
print(apply_discount("five", 20.0))
print(apply_discount(74.5, "twenty"))
print(apply_discount(0, 10))
print(apply_discount(74.5, 101))

And here’s the associated outputs:

80
100
50
0
59.6
The price should be a number
None
The discount should be a number
None
The price should be greater than 0
None
The discount should be between 0 and 100
None

Edit: I added in the last 2 “print()” functions to show that my code works for steps 3-6, though none of them are checked off the list as completed objectives.

2

Your function should never return None. When you print something in the function, it’s never reading the “return”

Look through the instructions again and note if it asks you to return or print a result.

3

Thank you. I should have caught that. I appreciate you pointing out the difference in what I was asking the program to do!

1 Like
4

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