Number comparison to find max/min in python

Question

I am a beginner in python. I have written a simple program to find greatest of 3 numbers. I get the right answer when I give input numbers having same number of digits (Eg. 50 8

Answer 1

You are yet another victim of dynamic typing.

When you read in data to your num variables, the variables are treated as strings.

When Python compares two strings using the < or > operator, it does so lexicographically -- meaning alphabetically. Here's a few examples.

'apple' < 'orange' //true
'apple' < 'adam' //false
'6' < '7' //true as expected
'80' < '700' //returns false, as 8 > 7 lexiographically

Therefore, you want to convert your input using int(), so < comparisons work as expected.

Code

num1=int("Enter 3 numbers\n")
num2=int(input())
num3=int(input())
if(num1 > num2):
    if(num1 > num3):
        print("The greatest number is "+ str(num1))
    else:
        print("the greatest number is "+ str(num3))
else:
    if(num2 > num3):
        print("The greatest number is " + str(num2))
    else:
        print("The greatest number is " + str(num3))