PYTHON CODE:

#Prompts the user to enter a positive nonzero 
#number and validates the input.
while True:
    try:
        num = float(input("Enter a positive non-zero number: "))
        if num > 0:
            break
        else:
            print("Invalid input number.")
    except ValueError:
        print("Invalid input number. Please re-enter a a positive non-zero number:.")
print(num, " is a valid input number.")

Executed Output:

Enter a positive non-zero number: -99
Invalid input number.
Enter a positive non-zero number: 0
Invalid input number.
Enter a positive non-zero number: 100
100.0  is a valid input number.