How to allow inputs above a certain number in python

Question

I have to get the user to input an integer, but it cannot be negative. However, whenever I test the program, if enter a negative number, it doesn't allow it. If I enter a negative number a second time, it will allow it. I know why, but I don't know what alternative I can use. Here's how it prints:

What would you like x to be? -5
Sorry, the number of juveniles must be positive. Please try again.
What would you like x to be? -5
What would you like y to be? -9
Sorry, the number of adults must be positive. Please try again.
What would you like y to be? -9
What would you like z to be? -10
Sorry, the number of seniles must be positive. Please try again. 
What would you like z to be? -10

This is my code:

x = int(input("What would you like x to be? "))
if x<0:
    print("Sorry, x must be positive. Please try again.")
    x = int(input("What would you like x to be? "))
y = int(input("What would you like y to be? "))
if y<0:
    print("Sorry, y must be positive. Please try again.")
    y = int(input("What would you like y to be? "))
z = int(input("What would you like z to be? "))
if z<0:
    print("Sorry, z must be positive. Please try again. ")
    z = int(input("What would you like z to be? "))

I've looked all around the place but cannot find a suitable alternative. Please help.

score 1 · Answer 1 · answered Mar 13 '16 at 19:39

1

Try something on these lines

while(true):
    x = int(input("What would you like x to be? "))
    if(x > 0):
        break;

answered Mar 13 '16 at 19:39

Bernardo Meurer

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score 0 · Accepted Answer · answered Mar 13 '16 at 19:38

if will only check once. Just replace your if statements by while:

x = int(input("What would you like x to be? "))
while x<0:
    print("Sorry, x must be positive. Please try again.")
    x = int(input("What would you like x to be? "))
y = int(input("What would you like y to be? "))
while y<0:
    print("Sorry, y must be positive. Please try again.")
    y = int(input("What would you like y to be? "))
z = int(input("What would you like z to be? "))
while z<0:
    print("Sorry, z must be positive. Please try again. ")
    z = int(input("What would you like z to be? "))

How to allow inputs above a certain number in python

2 Answers2