Why won't my output result in anything (not even an error)?

Question

size = input("What size pizza do you want? S, M, or L ")
addpepperoni = input("Do you want pepperoni? Y or N ")
extracheese = input("Do you want extra cheese? Y or N ")

S = 15 
M = 20
L = 25 
N = 0

if size == S: 
    if addpepperoni == N:
        if extracheese == N:
            bill = S 
            print ("cool")

Just testing it out to see if anything prints but nothing prints, not even an error. What am I doing wrong here?

`input()` returns strings; you are coming them to numbers. It also looks like you are asking for letter inputs like `"S"` but then comparing to `15`. That seems a little *unusual*. And you set `bill = S` with `S = 15`. Now `bill == 15`. Not sure what you're trying to do. — Mark, Jul 17 '21 at 20:14
Fair enough. It helps to print things out as you learn. For example adding `print(size, S)` before your `if` will show you why they are not equal. — Mark, Jul 17 '21 at 20:19
@Mark has a good suggestion, but `print(repr(size), repr(S))` may be better because the "repr" representation of an object typically has more information than the "str". Your string, for instance, would be `'S'` (quotes included) which gives more of a type hint. — tdelaney, Jul 17 '21 at 20:20

score 1 · Answer 1 · answered Jul 17 '21 at 20:25

The problem with this code is here:

if size == S: 
    if addpepperoni == N:
        if extracheese == N:

You have assigned S to 15 and N to 0, so what the code thinks you want to do is:

if size == 15: 
    if addpepperoni == 0:
        if extracheese == 0:

This is because you are checking if the variable size is equal to the variable S. A fix to this would be making it a string, for example:

if size == 'S': 
    if addpepperoni == 'N':
        if extracheese == 'N':

Another thing you can do to improve your code is to use and, to check multiple conditions with only one if statement, for example:

if size == 'S' and addpepperoni == 'N' and extracheese == 'N':

This would now check if size is equal to the string S and not the variable S, and the same for the other two. For more info on data types, go here!

This was extremely helpful!! thank you so much – Gadrri Jul 17 '21 at 20:41 — Gadrri, Jul 17 '21 at 20:41

signedav · Answer 2 · 2021-07-17T20:30:07.440

0

I guess you want to give the inputs 'S' and 'N', right? Then you should compare them to string and not to the integer values stored in the variables.

if size == 'S'
      if addpepperoni == 'N':
        if extracheese == 'N':
          bill = S 
          print ("cool")

edited Jul 17 '21 at 20:30

answered Jul 17 '21 at 20:21

signedav

146
1
4

1

In python 3.x, `input` always returns a string. Since `"15"` doesn't equal `15`, it still won't work. – tdelaney Jul 17 '21 at 20:23
Yeah, you're right. But since the questioner wants to input 'S' etc. it has no influence to the sollution. But I'll correct it. – signedav Jul 17 '21 at 20:29

score 0 · Answer 3 · edited Jul 17 '21 at 20:31

I think you misunderstand the concept of datatypes here. When you use an IDE to debug this code and put a breakpoint at the line with **if size == S: ** you would see that size has the value (for example) 'S' (which is the character typed into your terminal. But you are comparing it with S which is, in the context of your program, a variable that holds the value 15.

Since the Character 'S' and 15 are not equal your program will not run the following if checks and stop.

To fix this you should compare the size value which holds the character 'S' with the character 'S'. So, your check would be: **if size == 'S'**.

The same problem applies to the following checks you wrote.

score 0 · Answer 4 · answered Jul 17 '21 at 20:23

This is probably what you want in the specific example given but you would have to change it if you want combinations of outcomes.

This will only give a result of 'cool' if ALL conditions are met.

Ideally you would probably want classes here too.

size = input("What size pizza do you want? S, M, or L ")
addpepperoni = input("Do you want pepperoni? Y or N ")
extracheese = input("Do you want extra cheese? Y or N ")

S = 15
M = 20
L = 25
N = 0

if size == "S" and addpepperoni == "N" and extracheese == "N":
    bill = S 
    print ("cool")

Why won't my output result in anything (not even an error)?

4 Answers4