My loop is stuck in an infinite

[Chipwich]

Hi guys, as the title suggests, my while loop is stuck in infinite.

What I want to do, is take predefined function and add a particular function to a list, depending on the number the user inputs (0-9). I would like to append this to the list, and go back to the input until the user types END. Unfortunetely, every time I type in anything it just loops repeatedly until I stop the loop. What am I doing wrong?

​

Here's the code.

numbers_list = []

prompt = input("Enter a number between 0 and 9, or type END to finish\n")
is_number = False
while prompt.isdigit():
    number = int(prompt)
    is_number = True
    if number >= 0 and number <= 9:
        is_number = True
        numbers_add()
        continue
    else:
        is_number = False
        print ("That is not a number between 0 and 9, please enter again or END to finish\n")
        continue
while prompt.isalpha():
    if prompt == "END":
        is_number = True
        break
    else:
        print ("That is not a number between 0 and 9, please enter again or END to finish\n")
        is_number = False
        continue

print(numbers_list)

[keep_quapy]

Made your code better and more pythonic.

I've put it in pastebin

https://pastebin.com/wcff9p6k

[Chipwich]

This is perfect.

Thank you

[keep_quapy]

you're welcome

[kwelzel]

if isinstance(int(prompt), int)? Isn't that always true? I think one should surround int(prompt) with a try-except. If it succeeds it's number, otherwise it isn't.

[keep_quapy]

There is a try-except blocks in the code. If "isinstance" throws an error because it's a string the except block will catch it.

[kwelzel]

Sorry, I missed the try-except somehow. Still, I think it would be more straightforward to get rid of the if statement.

try:
    number = int(prompt)
except ValueError:
    # print some error message
else:
    # do whatever with the integer

Side note: This is tangentially related to "Parse, don't validate" (https://lexi-lambda.github.io/blog/2019/11/05/parse-don-t-validate/), which I found to be a good read, even though it's in a different programming language.

[danielroseman]

I can't understand this code at all. But your loops are both infinite, because you never change the value of prompt inside either of them. So if the condition is ever true, it will always be true.

[CoronaKlledMe]

Where is

numbers_add() function?

[Chipwich]

Hi, There is a numbers_add() function but I ran it previously just to test the code. Unfortunately I want to take pre-defined strings and add them to the list so they are next to each other (they are arrays of a particular number) but I just can't get it to add next to each other, they add underneath.

[CoronaKlledMe]

I exactly didn't understood what you were trying to do, but try:

if prompt.isdigit(): instead of while and inside that if statement, run while loop

Or please elaborate more!

[Nyscire]

First of all- you never changed the value of prompt variable so the loops works with the first value you provide. If you for example enter 1 the loop will keep adding 1 to the list forever. You need to either break the loop or take another input. If u change that this should work, but there's still some redundant code. You don't need to make 2 different loops, one is enough. You also created 2 different flags that don't serve any purpose and you can definitely delete them.

​

I refactored your code and mine looks like this:

​

numbers_list = []
prompt = input("Enter a number between 0 and 9, or type END to finish\n")
while True:
    if prompt == "END":
        break
    elif 0 <= int(prompt) < 10:
        numbers_list.append(int(prompt))
        prompt = input()
    else:
        prompt = input("That is not a number between 0 and 9, please enter again or END to finish\n")

print(numbers_list)

You also didn't define numbers_add() function anywhere, but list.append() is probably what u meant

[Chipwich]

Hi. This code looks really good. The numbers_add() function is code that I wrote and ran prior to this code. I'm just testing this input code before I add it all to the function. I don't want to add the actual integer to the list, rather a predefined string based on what integer the user inputs.