input of EOF halts program expected exit code 0, not 1

Question

The following solution to the grocery problem in CS50P provided an output that was identical to the one requested in the CS50P Grocery List problem description. It works perfectly in all three Python IDEs that I have (using Linux). Yet when using check50 I get this error:

Results for cs50/problems/2022/python/grocery generated by check50 v3.3.6
:) grocery.py exists
:( input of EOF halts program
    expected exit code 0, not 1

This is my code (the indentation of "main" is wonky here but not in codespace). The error capture code is indistinguishable from a problem set where it worked without issue. I have spent an hour trying to find the issue and am at a dead end.

def main():
        try:
            itemlist=[]
            while True:
                item = input ("Your grocery item:  ").strip().upper()
                itemlist.append(item)
                itemlist.sort()
                itemdict = {i:itemlist.count(i) for i in itemlist}
        except EOFError:
            print()
            for key in itemdict:
                print(itemdict[key], key)
    main()

UPDATE: I installed VSCode Desktop and ran this code with the debugger on. According to VSCode there are no errors or issues with this code. Ctrl-d works as it should and the output is identical to what is shown in the problem instructions.

I am really hoping that a CS50 staff member is monitoring this forum. This problem is no solvable for a beginner!

Answer 1

Your program doesn't work when user choose to end the program via Ctrl-d without provide any input. When the user does so, your program jumps to the exception part of the code, which reference an undeclared name "itemdict". "itemdict" is never declared essentially because the try part never run.

On a side note, I don't think it's necessary to sort itemList after every append. It's more logical to append all the items then sort.

Answer 2

Check50 will struggle to check as it still expects ctrl+d to stop the script in order to evaluate it further. Hence I would suggest you had a break at the end of your except EOFError:

Answer 3

The CS50 check50 finally dropped the exception error if I put the try and except lines inside the while loop. I don't understand why that should be when 4 IDEs (including VScode - which is what CS50 uses) ran it without complaint the way it was. Moving the while loop required that I rewrite the code since that immediately started generating a host of logic errors, but I just dealt with each, one at a time, until I got it working again.

This course is not for absolute beginners! There is no detailed instruction on how these different things work, what can go wrong and why it can go wrong like I remember getting for Fortran 40 years ago. I get about 100 errors per program (sometimes more). Nothing works as expected. I spend 90% of my time searching the internet for detailed explanations of how the different commands work (at least 4 to 6 hours per program). I am very close to going somewhere else.

If this happens again where the output is error free and exactly as requested in CS50's preferred IDE (any every other IDE) and then Check50 won't accept it, that's it for me!!

But hey, its free. I would NEVER pay for a certificate!