[SOLVED] [PYTHON] OR operator works like AND

czezz · 11-22-2019, 08:11 AM

Im having a problem with "OR" operator in "if" condition.
At the moment it works like AND.

quit() should be executed if any of the inputs is not numerical/intiger.
Meanwhile, it works ONLY if both inputs are non-numerical/intiger.

I tried to replace | with || and or. No success

Can anyone help me out here? What im doing wrong?

Code:

#!/usr/bin/python3
import sys

a=input("one: ")
b=input("two: ")

if( a.isdigit() | b.isdigit() ):
    print("User input is Number ")
else:
    print("One of provided inputs is not a number")
    quit()

print (a)
print (b)

dugan · 11-22-2019, 08:36 AM

That's not the "or" operator. The "or" operator is or.

Code:

if a.isdigit() or b.isdigit():

czezz · 11-22-2019, 08:39 AM

Hi Dugan, thanks for reply. Unfortunately, as I mentioned in my 1st post - "or" does not work neither.

dugan · 11-22-2019, 08:49 AM

Test with and, not or.

michaelk · 11-22-2019, 08:50 AM

Isn't that how or works?
1 or 1 = 1
1 or 0 = 1
0 or 1 = 1
0 or 0 = 0

You need to check each variable separately or use an and...

dugan · 11-22-2019, 08:51 AM

Code:

#!/usr/bin/python3
a=input("one: ")
b=input("two: ")

if a.isdigit() and b.isdigit():
    print("User input is Number ")
else:
    print("One of provided inputs is not a number")
    quit()

print (a)
print (b)

czezz · 11-22-2019, 09:00 AM

works!

FlinchX · 12-05-2019, 12:12 AM

OP, do you understand the difference between a digit and a number? If I wanted to check if a string represents a valid number, I'd rather try to convert it to a number and catch the exception if it fails.

czezz · 12-09-2019, 03:50 AM

number = 1 or more digits.
digit = 0 - 9
However, function isdigit() seems to be working for both.

dugan · 12-09-2019, 08:35 AM

@FlinchX: He's doing it correctly.

boughtonp · 12-09-2019, 12:31 PM

For the reference of anyone else confused:

In Python:
string.isdecimal() tests whether string contains only ASCII 0-9.
string.isdigit() tests whether string contains only ASCII 0-9 or superscript numbers.
string.isnumeric() tests whether every character has the Unicode "numeric" property.

Examples:

Code:

myvar = '1' -> returns true for isdecimal, isdigit, isnumeric
myvar = '1²' -> returns true for isdigit, isnumeric (false for isdecimal)
myvar = '½' -> returns true for isnumeric (false for isdecimal, isdigit)
myvar = '-1' -> returns false for all three
myvar = '1.0' -> returns false for all three
myvar = '1e10' -> returns false for all three

It's not clear from the OP's "...inputs are non-numerical/intiger" whether isdigit is correct, whether isdecimal might be preferred, or whether a different check would be better.