if elif is giving the wrong result

Question

It's only giving me the result of the first operation which is multiplied even if my input was the addition.

print('Calculator')
operation = input('Choose:\n Mltiply(*)\n Divise\(/)\n Add(+)\n Subbstract(-)\n ')
if operation == 'mutiply' or 'Multiply' or 'MULTIPLY' or '*':
    num1 = input('Write Your number :')
    num2 = input('Write your next number :')
    result = float(num1) * float(num2)
    print(result )
elif operation == 'DIVISE' or 'divise' or 'Divise' or '/':
    num1 = input('Write Your number :')
    num2 = input('Write your next number :')
    result = float(num1) / float(num2)
    print(result )
elif operation == 'Add' or 'add' or 'ADD' or '+':
    num1 = input('Write Your number :')
    num2 = input('Write your next number :')
    result = float(num1) + float(num2)
    print(result )
elif operation == 'Subbstract' or 'subbstract' or 'SUBBSTRACT' or '-':
    num1 = input('Write Your number :')
    num2 = input('Write your next number :')
    result = float(num1) - float(num2)
    print(result )
else:
    print('SYNTAX ERROR')

bitflip · Accepted Answer · 2022-10-20T22:34:00.827

1

Use the in operator

elif operation in {'DIVISE', 'divise', 'Divise', '/'}:

for every if/else block.

EDIT: You can find a good explanation here: Why does "a == x or y or z" always evaluate to True? How can I compare "a" to all of those?

edited Oct 20 '22 at 22:34

answered Oct 20 '22 at 22:27

bitflip

3,436
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score 1 · Answer 2 · answered Oct 20 '22 at 22:29

1

Use in

print('Calculator')
operation = input('Choose:\n Mltiply(*)\n Divise\(/)\n Add(+)\n Subbstract(-)\n ')
if operation.lower() in ['mutiply', '*']:
    num1 = input('Write Your number :')
    num2 = input('Write your next number :')
    result = float(num1) * float(num2)
    print(result )
elif operation.lower() in ['mutiply', '*']:
    num1 = input('Write Your number :')
    num2 = input('Write your next number :')
    result = float(num1) / float(num2)
    print(result )
..... replicate the above code for other operations ....

Why is your code always meet the fist condition?

operation == 'mutiply' or 'Multiply' or 'MULTIPLY' or '*' this always gives you True,

if 'Multiply':
     # Always return true

answered Oct 20 '22 at 22:29

Rahul K P

15,740
4
35
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Can I know what is the functionof operation.lower() ? – TNZ Oct 20 '22 at 23:21
1

`"ABCdef".lower()` -> `"abcdef"`. – Rahul K P Oct 20 '22 at 23:22
@TNZ Any reason you for the answer acceptance? – Rahul K P Oct 21 '22 at 18:05

if elif is giving the wrong result

2 Answers2