Highest Negative Value

Question

I don't understand why this doesn't work. I want to print the highest negative value from a series of user-inputted negative ints. E.g., user inputs: -1, -5, -3, program returns -1. But my program (below) is returning -5. Why is this? Is my code totally messed up? I know I can use a list and max way around it but I don't want to over-complicate the program.

x = 0
done = False
while not done:
    y = int(input("Enter another number (0 to end): "))
    num = y
    if num != 0:
        if num < x:
            x = num
    else:
        done = True
print(str(x))

Answer 1

Your operator should be greater than >, not less than < in order to take the maximum value. Initializing to -float('inf') ensures the first negative value passes the condition:

x = -float('inf')
while True:
    num = int(input("Enter another number (0 to end): "))
    if num != 0:
        if num > x:
            x = num
    else:
        break
print(x)

You can drop the done variable by using a while True...break instead.

---

I know I can use a list and max way around it but I don't want to over-complicate the program.

You can do this in a single line using iter with your sentinel 0 to call input repeatedly, collecting an iterable of negative numbers. map(int, ...) converts the iterable items to ints while max returns the maximum:

max(map(int, iter(input, '0')))

---

Demo:

>>> m = max(map(int, iter(input, '0')))
-3
-1
-4
-2
0
>>> m
-1