尝试除非两个输入相同

Question

I currently have a while loop that looks like this:

while True:
    try:
        entry1 = input("input the first number")
        entry2 = input("enter the second number")
        break
    except ValueError:
        print("number must be valid re-enter")

I want to add code that will reprompt the user to enter two different numbers if the user decides to enter two numbers that are the same. I tried using the following:

while True:
    try:
        entry1 = input("input the first number")
        entry2 = input("enter the second number")
        break
    except ValueError:
        print("number must be valid re-enter")
    try: 
        if entry1 == entry2:
            raise ValueError
        else:
            break
    except ValueError as err:
        print("The two numbers cant be the same. re-enter two unique numbers!"

Unfortunately this is not working. Does anyone know what is going wrong with my code?

Answer 1

you can use assert method to make sure the 2 inputs are different and catch with AssertionError if they don't.

while True:
    try:
        entry1 = int(input("input the first number"))
        entry2 = int(input("enter the second number"))
        assert entry1 != entry2
        break
    except ValueError:
        print("number must be valid re-enter")
    except AssertionError:
        print("The two numbers cant be the same. re-enter two unique numbers!")

Answer 2

For what you are describing you don't need all these exceptions. You could for example just use the comparison as condition for a while loop:

entry1 = entry2 = 0
while entry1 == entry2:
    entry1 = input("input the first number")
    entry2 = input("enter the second number")
    if entry1 == entry2:
        print("The two numbers can't be the same. re-enter two unique numbers!")

Edit: Of course it makes sense to cast the input to int and catch the error if that doesn't work. That could be like this:

entry1 = entry2 = 0
while entry1 == entry2:
    try:
        entry1 = int(input("input the first number"))
        entry2 = int(input("enter the second number"))
        if entry1 == entry2:
            print("The two numbers can't be the same. re-enter two unique numbers!")
    except ValueError:
        print("Please enter valid numbers")

Answer 3

break are called incorrectly. Too many try-except block.

 while True:
    try:
        entry1 = input("input the first number: ")
        entry2 = input("enter the second number: ")
    except ValueError:
        print("number must be valid re-enter.")

    if entry1 == entry2:
            print("The two numbers cant be the same. re-enter two "
                  "uniquen numbers!")
    else :
        break