有没有办法安排output中的项目

Question

I'm trying to build an arithmetic formatter that takes in math problems, arranges them side by side and print them out. My problem is that in the output, the operand of all the problems is changed to match that of the last problem and i don't know how to arrange them them side by side. How do i stop the operand from being changed in the output and how do i arrange the sums side by side. Thanks in advance.

def arithmetic_arranger(*problems):
    temp = "item1 + item2"
    print(f"Please enter your problems in this manner: {temp}")
    lines = "-------"
    # check number of problem first

    if len(problems) > 5:
        print("Error.Too many problems")
    else:
        pass

    # check the length of each number
    for i in problems:
        a = i.split(" ")
        val1 = a[0]
        val2 = a[2]
        if (len(val1)) > 4 or (len(val2)) > 4:
            print("Error: Numbers cannot be more than four digits.")
        else:
            pass

    # check the operator
    for i in problems:
        a = i.split(" ")
        operand = a[1]
        if operand == "+" and operand == "-":
            pass
        elif operand != "+" and operand != "-":
            print("Error.operand must be + or -")

    # test only digits
    for i in problems:
        a = i.split(" ")
        val1 = a[0]
        val2 = a[2]
        if val1.isnumeric() and val2.isnumeric():
            pass
        else:
            print("Error. Numbers must contain only digits")
    # carry out the problems and format it
    if operand == "-":
        result = float(val1) + float(val2)
    else:
        operand == "+"
        result = float(val1) - float(val2)
# print it out
    for i in problems:
        solution = "  {}\n{} {}\n{}\n\n".format(val1, operand, val2, lines)
        print(solution)

arithmetic_arranger("223 - 3144", "999 + 1313", "45 + 43", "123 + 49")

This is the expected output:

   223       999      45      123
- 3144    + 1313    + 43    +  49
------    ------    ----    -----

Answer 1

You have a couple of logic errors. Ex: if operand == "+" and operand == "-": It can't be both

Also, in the # test only digits loop , val1 and val2 get re-assigned in each iteration of the loop. So after the loop is completed, they have the values of the last items. You can either make them lists, or move to printing code to inside that for loop.

I have combined everything into one loop.

def arithmetic_arranger(*problems):
    # check the operator
    for i in problems:
        a = i.split(' ')
        operand = a[1]
        if operand != "+" and operand != "-":
            print("Error.operand must be + or -")
            continue
        if not (a[0].isnumeric() and a[2].isnumeric()):
            print("Error. Numbers must contain only digits")
            continue
        # carry out the problems and format it
        val1 = int(a[0])
        val2 = int(a[2])
        if operand == "-":
            result = int(val1) - int(val2)
        else:
            result = int(val1) + int(val2)
        # print it out
        solution = "  {0:5}\n{1:>2} {2}\n  {3:5}\n\n".format(val1, operand, val2, result)
        print(solution)

arithmetic_arranger("223 - 3144", "999 + 1313")