Scientific Computing with Python Projects - Arithmetic Formatter

[alexwtom02]

I’ve created a solution to this problem which seems to always produce the correct output for me when ran in a seperate replit. However, whenever I run the tests on the replit you have provided it fails the tests. If anyone can explain why this would be appreciated.

Your code so far

edit: for some reason it won’t post my code with the indentations but I believe there are no indentation issues

def arithmetic_arranger(problems, show_answers=True):
  if len(problems) > 5:
    return "Error: Too many problems."
  # create lines for solution
  line1 = f''
  line2 = f''
  line3 = f''
  line4 = f''
  count = 0
  # find where to split the string and value of the operator
  for problem in problems:
    count += 1
    index = problem.find(' ')
    operator = problem[index + 1]
    first_number = problem[0:index]
    second_number = problem[index + 3:]
    # determine if solution requires addition or subtraction
    if operator == "+":
      sol = int(first_number) + int(second_number)
    elif operator == "-":
      sol = int(first_number) - int(second_number)
    else:
      return "Error: Operator must be '+' or '-'."
    if first_number.isdigit():
      pass
    else:
      return "Error: Numbers must only contain digits."
    if second_number.isdigit():
      pass
    else:
      return "Error: Numbers must only contain digits."
    if len(first_number) > 4:
      return "Error: Numbers cannot be more than four digits."
    else:
      pass
    if len(second_number) > 4:
      return "Error: Numbers cannot be more than four digits."
    else:
      pass
    # create strings to be added to solution lines
    x = ''
    y = ''
    z = ''
    s = ''
    # find how many spaces to add to each item to make soluution right aligned
    if len(first_number) >= len(second_number):
      length_of_solution = len(first_number) + 2
    else:
      length_of_solution = len(second_number) + 2
    number_of_times_to_add_space1 = length_of_solution - len(first_number)
    number_of_times_to_add_space2 = length_of_solution - len(second_number) -1
    number_of_times_to_add_space3 = length_of_solution - len(str(sol))
    # add the required spaces and then determine if its the last problem to decide if there needs to be another four spaces to seperate the problems
    if count < len(problems):
      for i in range(number_of_times_to_add_space1):
        x = ' ' + x
      x = x + first_number
      for i in range(number_of_times_to_add_space2):
        y = ' ' + y
      y = operator + y + second_number
      for i in range(number_of_times_to_add_space3):
        s = ' ' + s
      s = s + str(sol)
      line1 = line1 + x + '    '
      line2 = line2 + y + '    '
      line4 = line4 + s + '    '
      for i in range(length_of_solution):
        z = '-' + z
      line3 = line3 + z + '    '
    else:
      for i in range(number_of_times_to_add_space1):
        x = ' ' + x
      x = x + first_number
      for i in range(number_of_times_to_add_space2):
        y = ' ' + y
      y = operator + y + second_number
      for i in range(number_of_times_to_add_space3):
        s = ' ' + s
      s = s + str(sol)
      line1 = line1 + x
      line2 = line2 + y
      line4 = line4 + s
      # create dashed line
      for i in range(length_of_solution):
        z = '-' + z
      line3 = line3 + z
      # create final answer
  arranged_problems = f'{line1}\n{line2}\n{line3}\n{line4}'
  return arranged_problems

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Challenge Information:

Scientific Computing with Python Projects - Arithmetic Formatter

freeCodeCamp.org

[pkdvalis]

Can you please post the error messages? They usually explain what the problem is (and it’s usually extra spaces at the end of your lines or somewhere)

[pkdvalis]

An assertion error gives you a lot of information to track down a problem. For example:

AssertionError: 'Year' != 'Years'
- Year
+ Years
?     +

Your output comes first, and the output that the test expects is second.

AssertionError: ‘Year’ != ‘Years’

Your output: Year does not equal what’s expected: Years

- Year
+ Years
?     +

- Dash indicates the incorrect output
+ Plus shows what it should be
? The Question mark line indicates the place of the character that’s different between the two lines. Here a + is placed under the missing s .

Here’s another example:

E       AssertionError: Expected different output when calling "arithmetic_arranger()" with ["3801 - 2", "123 + 49"]
E       assert '  3801      123    \n   - 2     + 49    \n------    -----    \n' == '  3801      123\n-    2    +  49\n------    -----'
E         -   3801      123
E         +   3801      123    
E         ?                ++++
E         - -    2    +  49
E         +    - 2     + 49    
E         - ------    -----
E         + ------    -----    
E         ?                +++++

The first line is long, and it helps to view it as 2 lines in fixed width characters, so you can compare it character by character:

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

Again, your output is first and the expected output is second. Here it’s easy to see extra spaces or \n characters.

E         -   3801      123
E         +   3801      123    
E         ?                ++++

Here the ? line indicates 4 extra spaces at the end of a line using four + symbols. Spaces are a little difficult to see this way, so it’s useful to use both formats together.

I hope this helps interpret your error!

[pkdvalis]

I’ve edited your code for readability. When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make it easier to read.

You can also use the “preformatted text” tool in the editor (</>) to add backticks around text.

See this post to find the backtick on your keyboard.
Note: Backticks (`) are not single quotes (').

[alexwtom02]

Hi thanks for your reply.
I can’t copy and paste the error code for some reason but the assertion error given is something like:

    1         1
  + 2    - 9380
- ---    ------
+ ---    ------
?              +
+   3     -9379

If I am correct this means that there is a space after the dashed lines. However when I add the word test to the end of the dashed line in the variable passed to the return call at the end (arranged_problems = f’{line1}\n{line2}\n{line3}test\n{line4}') it gives that line as:

- ---    ------test

This shows that there is no space and so I am confused. If you could help further that would be appreciated.

Edit:
I’ve also tried using line3 = line3.rstrip() but that hasn’t solved it

[pkdvalis]

@pkdvalis

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

You’re likely correct, there is a space there. Can you show this type of error line as well, the assert?

You might have to right-click/copy. You can do it, it’s just kind of fiddly the way it handles it.

[alexwtom02]

Hi,
Thank you for your help. I’ve now got it to pass all 10 tests