why does the system decides which is bigger by scanning only the first number - Python

Question

this is my code, and when I input numbers that has two digits and one number that has only one digit, (e.g. when I input 47, 57, and 9) it results to 9 which is the smallest. please help.

def maximum(a, b, c):
        list = [a, b, c]
        return max(list)


num_one = input("Enter 1st Number: ")
num_two = input("Enter 2nd Number: ")
num_three = input("Enter 3rd Number: ")
num4 = 0

if num_one.isdecimal():
    if num_one.isdecimal():
        if num_one.isdecimal():
            a = num_one
            b = num_two
            c = num_three
            print(maximum(a, b, c))
        else:
            print("wrong input")
    else:
        print("wrong input")
else:
    print("wrong input")

Does this answer your question? [How can I read inputs as numbers?](https://stackoverflow.com/questions/20449427/how-can-i-read-inputs-as-numbers) — Tomerikoo, Jan 31 '21 at 17:16
`input()` always returns a string. Comparing strings is done lexicographically, so `"9" > "45"` is indeed true... — Tomerikoo, Jan 31 '21 at 17:17
try `print(maximum(int(num_one), int(num_two), int(num_three)))` — Ivan, Jan 31 '21 at 17:27
@Ivan it would easier and more readable if they just did `num_x = int(input(...))`... — Tomerikoo, Jan 31 '21 at 18:15

score 1 · Accepted Answer · edited Jan 31 '21 at 18:33

1

When you use input() it automatically takes in a string. So you have to convert it to a float or integer later. Also, the keyword and is useful instead of using three if statements:

def maximum(a, b, c):
    list = [a, b, c]
    return max(list)

num_one = input("Enter 1st Number: ")
num_two = input("Enter 2nd Number: ")
num_three = input("Enter 3rd Number: ")

if num_one.isdecimal() and num_two.isdecimal() and num_three.isdecimal():
    a = float(num_one)
    b = float(num_two)
    c = float(num_three)
    print(maximum(a, b, c))
else:
    print('Wrong input')

edited Jan 31 '21 at 18:33

Tomerikoo

18,379
16
47
61

answered Jan 31 '21 at 18:03

ph140

478
3
10

2

Worth noting that `maximum` is just an unnecessary wrapper to the built-in `max`. i.e. doing `max(a, b, c)` will work exactly the same – Tomerikoo Jan 31 '21 at 18:17

why does the system decides which is bigger by scanning only the first number - Python

1 Answers1