Scientific Computing with Python Projects - Arithmetic Formatter

Python
1

Hi there. I wrote code that seems to have the desired output but some reason it does not pass the tests. It also says it doesn’t pass the check for giving an error message when letters are added instead of numbers, although it does actually do that when I run it.

I don’t understand what I’m doing wrong.

def arithmetic_arranger(problems, show_answers=False):
    if len(problems) > 4:
        return 'Error: Too many problems.'
    toplist = []
    bottomlist = []
    dasheslist = []
    answerslist = []
    answer = 0
    for problem in problems:
        splitlist = problem.split() #break problems into their separate elements
        if not splitlist[0].isnumeric() or not splitlist[2].isnumeric: #check only numbers were added
            return 'Error: Numbers must only contain digits.'
        if len(splitlist[0]) > len(splitlist[2]): #see which number is longer and set up the length
            length = len(splitlist[0]) + 2
        else:
            length = len(splitlist[2]) + 2
        if length > 6:
            return 'Error: Numbers cannot be more than four digits.'
        spaceslength = length - len(splitlist[0])
        toplist.append(" " * spaceslength) #add proper number of spaces for top number to be right aligned
        toplist.append(splitlist[0]) #add first number
        toplist.append("    ") #add spaces to separate the problems
        operator = splitlist[1]
        if operator == "*" or operator == "/": #check for invalid functions
            return "Error: Operator must be '+' or '-'."
        elif operator == "+":
            answer = int(splitlist[0]) + int(splitlist[2])
        elif operator == "-":
            answer = int(splitlist[0]) - int(splitlist[2])
        answerslist.append((" " * (length - len(str(answer))))) #create the answers string, making it right aligned
        answerslist.append(str(answer))
        answerslist.append("    ")
        bottomlist.append(operator)
        bottomlist.append(" " * (length - len(str(splitlist[2])) - 1))
        bottomlist.append(splitlist[2])
        bottomlist.append("    ")
        dasheslist.append("-"*length)
        dasheslist.append("    ")
    topliststring = "".join(toplist)
    bottomliststring = "".join(bottomlist)
    dashesliststring = "".join(dasheslist)
    answersliststring = "".join(answerslist)
    if show_answers==False:
        problems = "\n".join([topliststring, bottomliststring, dashesliststring])
    else:
        problems = "\n".join([topliststring, bottomliststring, dashesliststring, answersliststring])
    return problems

print(f'\n{arithmetic_arranger(["32 + 698", "3801 - 2", "45 + 43", "123 + 49"], True)}')```
2

It will help to use repr() to see raw string data. There’s formatting that you cannot see.

If I pass this to your function:

print(repr(arithmetic_arranger(["3801 - 2", "123 + 49"])))

output is

'  3801      123    \n-    2    +  49    \n------    -----    '

Error says:

arithmetic_arranger(["3801 - 2", "123 + 49"]) should return

'  3801      123\n-    2    +  49\n------    -----'

I would focus on this first, make sure your output is exactly the same spacing indicated by the hint.

1 Like
3

yes! I just solved it. My problem had to do with adding extra white space to the end of my string.

1 Like
4

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